UL 2 – Part VI.

Airworthiness requirements SFD ultralight gliders, ultralight motor gliders, replicas of historic gliders

Text as of: 26. 03. 2019

CHANGE SHEET

Date of issue of the change	Edited/deleted/new paragraphs:	Date of inclusion	Ranked

CONTENT

DEFINITIONS, ABBREVIATIONS AND LABELS
TITLE A - GENERAL
SUBPART B - FLIGHT CHARACTERISTICS AND PERFORMANCE
TITLE C - STRENGTH
TITLE D - DESIGN AND CONSTRUCTION
TITLE E - PROPULSION SYSTEM
TITLE F - EQUIPMENT
TITLE G - OPERATING LIMITATIONS AND DATA
APPENDIX 1 – RESCUE SYSTEMS

 

DEFINITIONS, ABBREVIATIONS AND LABELS

1. General definitions

Tíha G = m∙g [N]

where: m mass [kg]
g gravitational acceleration [g = 9,81 m/s]

The International Standard Atmosphere (MSA) is defined as follows:

1. 1. air is a perfect dry gas
   2. the temperature at the height H = 0 m is 15 °C
   3. air pressure at height H = 0 m is 1013,25 hPa
   4. the temperature gradient from zero height to a height where the temperature reaches −56 °C is −0,0065 °C/m
   5. the air density ρ under the stated conditions is 1,225 kg/m³

If in the text part there is a reference to the relevant authority, for the purposes of fulfilling these requirements, the authorized person is meant, i.e. the Light Aircraft Association of the Czech Republic (hereinafter referred to as the authorized person).

2. Definition of speeds

tr>V_Fdesign speed with flaps extended

VA	design speed of turns (maneuvering)
VB	design speed for maximum gust size
VD	steep descent design speed
VDF	the highest speed demonstrated by a flight test
VFE	maximum allowable speed for use of flaps
VH	maximum speed in level flight at maximum permissible sustained power
VLO	maximum allowable speed for extending the landing gear
VNE	maximum unexceeded speed
VRA	maximum speed in strong turbulence
VS	stall speed or the lowest steady speed at which the glider is still controllable
VSO	stall speed or the lowest steady speed at which the glider is still controllable in the landing configuration
VS1	stall speed or the lowest steady speed at which the glider is still controllable in the specified configuration
VSF	calculated stall speed with fully extended flaps at maximum take-off weight
VT	maximum permissible speed for towing
VW	maximum allowable speed when taking off with a winch
VY	speed at best climb
CAS	calibrated airspeed (CAS = Calibrated Airspeed). Indicated airspeed corrected for instrument and installation error.
EAS	equivalent flight speed (EAS = Equivalent Airspeed). Calibrated airspeed, adjusted for adiabatic compressibility at given altitude. For MSA at sea level, the equivalent airspeed is equal to the calibrated airspeed.
IAS	indicated airspeed (IAS = Indicated Airspeed) is the airspeed as indicated by its speedometer (connected to the pitot-static system), calibrated with respect to the adiabatic compression of the air stream in a standard atmosphere at sea level, uncorrected for airspeed system errors.
CAS	true airspeed (TAS = True Airspeed). Flight speed in still air. Actual airspeed is the equivalent airspeed multiplied by (r/r0)½.

3. Definition from the field of strength

Supporting structure	There are those parts of the structure of an ultralight glider whose failure would seriously compromise the safety of the aircraft.
Maximum take-off weight MTOM	The largest weight at which an ultralight glider meets airworthiness guidelines
Weight of empty glider	It is stipulated in UL2-VI § 29
Operating load	The maximum load that can be expected in operation
Numerical load	The service load multiplied by the appropriate factor of safety, normally 1,5.
Operating multiple n	The ratio of the total aerodynamic force acting perpendicular to the flight path and the total weight of the glider. in straight-line steady flight this multiple is equal to one. Operating loads can be expressed in terms of aerodynamic forces or acceleration forces.

 

TITLE A - GENERAL

1. Purpose

This building code sets the minimum airworthiness requirements for ultralight gliders and replicas of historic gliders, which need to be met so that the use of the glider for the specified purpose is problem-free and does not jeopardize the safety of air traffic as well as the safety of third parties.

UL2-VI. § 3 Applicability

This Regulation contains minimum airworthiness requirements for:

1. UL gliders with:

a. maximum 2 places a
b. with a maximum take-off weight of no more than 250 kg in the single-seat version and 400 kg in the two-seat version and
c. at a minimum speed of no more than 65 km/h at the maximum permissible take-off weight in the landing configuration.

Note: The maximum flight weight when using the integrated rescue parachute is increased by 15 kg for a single-seater and 25 kg for a two-seater glider.

2. Powered UL gliders with:

a. maximum 2 places a
b. with a maximum take-off weight of no more than 300 kg in the single-seat version and 450 kg in the two-seat version and

Note: The maximum flight weight when using the integrated rescue parachute is increased by 15 kg for a single-seater and 25 kg for a two-seater glider.

c. on the ground with a detachable or in-flight retractable propulsion unit. The glider is capable of either independent take-off, or – after take-off using other means, maintaining level flight in defined atmospheric conditions.
d. at a minimum speed of no more than 65 km/h at the maximum permissible flight weight in the landing configuration.

3. Replicas of historic gliders whose original design was created before January 1, 1955 and production ceased before January 1, 1975, the design of which is similar to that of the original aircraft.

The maximum take-off weight does not exceed 600 kg, while the falling speed V_SO does not exceed 65 km/h.

 

SUBPART B - FLIGHT CHARACTERISTICS AND PERFORMANCE

I. In general

UL2-VI § 21 Keeping a license

1. 1. Each requirement of this Chapter must be demonstrated by testing a glider of a given type for every possible combination of weight and center of gravity position over the entire range of permissible configurations in which the glider will be operated.
   2. The pass must be performed for all configurations (eg, aerobrakes, flaps, landing gear positions, etc.) in which the glider can be operated, so that none are omitted.

Note: Subpart B does not list all the flight tests that are required to meet the certification requirements. The responsible authority has the right to determine the scope of the flight tests.

UL2-VI § 21 (explanatory notes)

1. Instrumentation for flight tests

a. For the tests, the glider must be equipped with suitable instruments for simple performance of the required measurements and observations. The authorized person may require the use of special measuring devices if conclusive results cannot be obtained by other means.
b. In the initial stage of the test program, the accuracy of the instruments must be determined as well as their calibration curves. Particular attention should be paid to errors in the airspeed indication system. The effect of the actual current configuration of the glider during flight tests must also be taken into account.

2. The following ground tests must be performed prior to flight tests:

a. Measurement:

– stiffness of control routes,
– steering friction,
– tensioning of control ropes of closed control rope routes,
– maximum deflections of control surfaces and flaps

b. Weighing the aircraft and determining the operational positions of the center of gravity.

3. Functional tests:

All ground functional tests must be performed before flight testing begins. In particular, it is necessary to test the problem-free operation of the towing rope switch at all possible angles of the towing rope in operation and in the expected range of applied forces.

UL2-VI § 23 Limitation of load distribution

1. Weight ranges and CG position ranges in which the glider can be safely operated shall be established. The demonstrated range of CG positions shall be from the extreme forward position to +1%SAT or +10 mm beyond the extreme aft position, whichever is larger.
2. The range of the position of the center of gravity must not be less than that which occurs when the weight of each crew member varies from 70 kg to 100 kg.

UL2-VI § 25 Weight limits

Maximum weight. The maximum weight must be determined so that:

1. It was not greater than:

a. the highest weight chosen by the applicant, a
b. the design weight, which is the highest weight for which the certificate is carried out considering all the strength load cases of this regulation.

2. It was not less than the mass which consists of the weight of the equipped glider, including the weight of the crew member of 100 kg for a single seat glider or of the weight of the crew members of 170 kg for a two seat glider, the minimum equipment required and the ballast.

UL2-VI § 25 (explanatory notes)

Recommendation: When determining the maximum weight, possible additional equipment should also be considered and attention should also be paid to the possible increase in weight during equipment changes, repairs, etc.

UL2-VI § 29 Weight of the equipped glider and the corresponding position of the center of gravity

1. The weight of the rigged glider and the appropriate position of the center of gravity must be determined by weighing the glider

a. with:

i. a permanently built-in load,
ii. required minimum equipment,
iii. installed rescue system.

b. without:

i. the weight of the crew member(s), a
ii. other easily removable load items.

2. The configuration of the glider when determining the weight of the equipped glider must be precisely defined and easily re-attainable at any time.

UL2-VI § 31 Burden

There are two types of load:

1. 1. 1. fixed load for correcting the position of the center of gravity of the glider a
      2. a removable load that is used to increase the weight of a crew member so that the position of the center of gravity is kept within permissible limits. This load can be adjusted before the start of the flight, but not during it.

II. Flight performance

UL2-VI § 45 In general

Proof of compliance with the requirements of this Chapter B for flight performance must be performed in calm air, with the conversion of measured performance to MSA at H = 0 m.

UL2-VI § 49 Falling speed

1 V_SO is the stall speed (CAS), if achievable, or the minimum steady-state speed at which the glider is still controllable, with:

a. extended landing gear in the landing position,
b. flaps in the landing position,
c. such a position of the aerodynamic brakes (extended or retracted) that causes the lowest V value_SO,
d. weights corresponding to the maximum weight, a
e. the position of the center of gravity in the most unfavorable position within the permissible limits.

2 V_S1 is the stall speed (CAS), if attainable, or the minimum steady speed at which the glider is still controllable, when:

a. such glider configuration in which the speed V_S1 verified during tests,
b. maximum glider weight, a
c. the most unfavorable position of the center of gravity for this configuration.

3. For motor gliders, the following must also be used during the test:

a. engine idling (inlet closed),
b. propeller in take-off position, a
c. cooling shutters closed.

4 V_SO to V_S1 must be determined by flight tests in accordance with the procedures according to UL2-VI § 201.

UL2-VI § 51 Take-off of a motor glider

1. The length of take-off at maximum weight and in no wind, from rest to reaching a height of 15 meters above the ground and at a speed of not less than 1,3 V_S1 must not exceed 600 meters when taking off from a dry, flat, grassy surface.

UL2-VI § 65 Ascent of a motor glider

1. The minimum rate of climb must not be lower than 1,25 m/s ori?

a. maximum engine take-off power,
b. retracted chassis,
c. max. take-off weight,
d. flaps in take-off position, a
e. without exceeding the specified operating limits of the drive unit.

UL2-VI § 73 Descent at high speed

If the glider's rate of descent at V_NE less than 10 m/s, a device must be used to increase the rate of descent to a value equal to or greater than 10 m/s.

UL2-VI § 75 Descent, approach

If the glideslope at 1,3 × V_S0 greater than 7, a device must be used to reduce the slip to a value less than or equal to 7.

III. Maneuverability and agility

UL2-VI § 143 In general

1. It must be possible to make a smooth transition from one position to another (including turns and glides) with the glider under all probable flight conditions without extraordinary demands on the pilot's skill, alertness and strength and without the risk of exceeding operational multiples.

2. All unusual flight characteristics that are observed during flight tests to obtain proof of compliance with the requirements of the regulation and all noticeable changes in flight characteristics caused by rain must be checked.

UL2-VI § 143 2. (explanatory notes)
Observed properties include stall speed and drag behavior.

3. If the pilot's applied control forces appear unusually high, compliance with the control force limits must be demonstrated by quantitative tests

(Force acting on handle or pedal)	Longitudinal steering [tax]	Lateral steering [tax]	Directional control [tax]	Aerodynamic brakes Tow rope switch Flap flaps [tax]
a. short-term action	10	10	20	10
b. prolonged action	2,0	1,5	10

UL2-VI § 145 Longitudinal steering

1. At any speed lower than 1,3xVS1, it must be possible to change the position around the lateral axis by interfering with the longitudinal control so that the glider immediately accelerates again to a speed of 1,3xVS1.
Test conditions: All possible glider configurations, glider balanced at 1,3xVS1 (if balance available).

2. It must be possible to change the configuration of the glider (landing gear, aerodynamic brakes, flaps, engine power, etc.) within the entire range of permitted operational limitations without special pilot skill without exceeding the control forces specified in UL2-VI § 143.

3. It must be possible without special piloting skill to maintain the glider in steady straight flight or in a climb:

a. when extending and retracting the flaps in the aerofoil,
b. when retracting and retracting the aerodynamic brakes at speeds between 1,1 x V_S1 and 1,5 x V_S1, where V_S1 is the stall speed with the airbrakes either extended or retracted, whichever is higher for the given brake position.
c. in the case of a motor glider with a smooth change of flap settings within the permitted range at a speed of 1,1 V_S1 and simultaneously setting the maximum continuous power.

UL2-VI § 151 Aerovlek

1. If the glider is equipped for air towing, the air towing must be proven for speeds up to V_T, without:

a. excessive control forces and deflections to keep the glider on a stable flight path with the wings in a horizontal position,
b. exceeding the control forces specified in UL2-VI § 143 at speeds up to V_T,
c. Difficulty in recovering a normal position after the glider has deviated laterally or vertically, a
d. there is a danger that the end or ends of the rope will get caught in some part of the glider when the tow rope is released.

2. Airfoil tests must be performed with a crosswind component of at least 0,2 x V_SO.

3. Fulfillment of the following requirements must be demonstrated:

a. From the starting position of the glider in the normal towing position, the glider is brought using directional and lateral control out of this position with a lateral inclination of 30° to the towing aircraft. The pilot must then be able to return the glider to its normal position in the airfoil without requiring extraordinary skill on the part of the pilot.
b. The glider must be placed in an elevated position above the flight path of the towing aircraft (approximately 15° above the flight path) and also in a lowered position (below the propeller jet of the towing aircraft). In both cases, the pilot must be able to return the glider to its normal position in the aerofoil without requiring extraordinary pilot skill

4. A suitable range of towing rope lengths must be tested and determined.

5. Tests must be performed for each position of the towing rope release mechanism and for each configuration that are approved for the towing.

UL2-VI § 152 Take-off using a winch and a motor vehicle

1. If the glider is equipped for winch and/or motorized take-off, these take-off methods must be demonstrated at speeds up to V_W, without:

a. after detaching from the ground, maintaining the wing in a horizontal position and releasing the towing rope at any stage of take-off required extraordinary skill or strength of the pilot,
b. excessive forces and steering deviations were required, namely during a steady climb,
c. there was excessive pitch oscillation,
d. during climbing flight, it was necessary to use hand control forces in the "suppressed" direction. If leveling is used, the position during the climb must be given.

2. Tests shall be conducted with crosswind components not less than 0,2 x V_SO.

UL2-VI § 152 (explanatory notes)
To demonstrate compliance with winch take-off requirements, a minimum of 6 winch take-off tests covering a range of speeds up to VW must be completed. During these tests, a range of trip points should be selected along the flight path to account for the normal operating range and emergency trip.

UL2-VI § 153 Approach and landing

1. With a crosswind component of not less than 0,2 x V_SO it must be possible to perform a normal approach and landing, including landing and taxiing, without the pilot's special aeronautical skill and without showing a tendency to spin out of control on the ground.

2. After landing, there must not be an excessive tendency to turn, to oscillate or to overturn.

3. Use of aerodynamic brakes during approach and landing above or including 1,2 x V speed_S1 – while V_S1 is greater than the values ​​that refer to the configuration with the aerodynamic brakes in or out - it must not cause excessive changes in steering force or steering deflections or affect the controllability of the glider.

UL2-VI § 155 Force in longitudinal control during turns

It must be proven that the steering force in longitudinal control in a steady turn or when taking a turn increases in proportion to the load multiple.

UL2-VI § 161 Balancing

In general

After balancing the glider, the requirements of this paragraph must be met without the pilot applying any further forces or motion to the main control paths or to the relevant balance.

1. Transverse and directional balance

a. Transverse balancing

It must be possible to balance the glider so that in steady straight flight at a speed of 1,4 x V_S1, flaps in all flight positions, aerodynamic brakes, and, if available, with the landing gear in the retracted position so that it is not prone to yaw or pitch with the ailerons released and the rudder held in neutral.

b. Directional balancing

It must be possible to balance the glider so that in steady straight flight at a speed of 1,4 x V_S1, flaps in all flight positions, airbrakes, and, if available, with the landing gear retracted so as not to be prone to yaw with rudder released and aileron control held in neutral.

2. Longitudinal balancing

a. If the glider does not have adjustable balance in flight, it must be balanceable at all positions of the center of gravity in the speed range of 1,2 x V_S1 and 2,0 x V_S1 .

b. If the glider has adjustable balance in flight, it must meet the following requirements without the pilot applying any further forces or motion to the main control paths or to the relevant balance:

i. The glider must be balanceable in the speed range of 1,2 x V_S1 up to 2,0 x V_S1.with flaps in landing position, airbrakes engaged and landing gear in landing position.
ii. The glider must be towable in a speed range of 1,4 x V_S1 up to V_T.
iii. In the extreme positions of the balanced state in the speed range of 1,1 x V_S1 up to 1,5 V_S1 the steering force must be less than 10 daN.

IV. Stability

UL2-VI § 171 In general

The glider must meet the conditions of UL2-VI § 173 to UL2-VI § 181 inclusive. In addition, the glider must have sufficient stability and provide the pilot with sufficient response to control forces ("control feel") in all modes and flight conditions expected in normal operation.

UL2-VI § 173 Longitudinal static stability

Airspeed shall return to baseline from a deviation of ±15% or ±15 km/h of the balanced steady speed, whichever is greater, if the control force for the steady configuration without stall is reduced in the speed range to the VNE speed and if is achievable up to speed V_FE and downwards to the corresponding minimum airspeed.

UL2-VI § 175 Proof of longitudinal static stability

The power-to-speed control curve must have a stable slope under the following conditions:

1. Flight configurations:

a. at all speeds from 1,1 x V_S1 to V_NE,
b. flaps in position for overflight and circling,
c. undercarriage retracted,
d. Glider balanced for a speed of 1,4 x V_S1 and 2 x V_S1 (if equipped with balancing), a
e. retracted aerodynamic brakes.

2. Approach configuration:

a. at all speeds between 1,1 x V_SO to V_FE,
b. flaps in landing position,
c. extended landing gear,
d. glider balanced at a speed of 1,4 x V_SO (if equipped with balancing), a
e. aerodynamic brakes both retracted and extended.

3. Motor glider climb:

a. at all speeds between 0,85V_Y or 1,05V_S1, whichever is higher, up to 1,15 V_Y,
b. undercarriage retracted,
c. flaps in climb position,
d. maximum weight,
e. maximum performance,
f. glider balanced at speed V_Y (if equipped with a balancing device).

4. Motor glider cruise flight:

a. at all speeds between 1,3V_S1 to V_NE,
b. undercarriage retracted,
c. flaps retracted,
d. maximum weight,
e. power for level flight at 0,9 V_H,
f. glider balanced for level flight.

5. Motor glider approach:

a. at all speeds between 1,1V_S1 to V_FE,
b. extended landing gear,
c. flaps in landing position,
d. glider balanced at 1,5V_S1 (if equipped with a balancing device),
e. engine power set to idling,
f. aerodynamic brakes retracted and extended, a
g. propeller in take-off position (if it is adjustable).

UL2-VI § 175 (explanatory notes)

1. As a rule, qualitative tests are sufficient for the "aerodynamic brakes extended" configuration.
2. Flap positions should also include, if assumed, a negative setting (see UL2 VI § 335).

UL-VI § 177 Transverse and directional stability

1. If the glider is in steady straight-line flight, and when the aileron and rudder controls are gradually set in the opposite direction, each increase in the sideslip angle must correspond to an increased yaw deflection. This relationship may not be linear.

2. During a glide, there must not be such a reversal of control forces that would require special skill of the pilot in controlling the glider.

UL2-VI § 181 Dynamic stability

All the rapid oscillations that occur between the stall speed and the V speed_DF, must be s

a. Free, a
b. fixed

heavily dampened by the main driving routes.

V. Drag and drop properties

UL2-VI § 201 Drag characteristics in direct flight

1. Stall tests shall be conducted with the initial steady flight speed reduced by approximately 2 km/h per second until a stall condition is reached, manifested by either a downward pitching of the fuselage or pitching over the wing, and which is not immediately controllable , or reaching the height control stop. It must be possible to steer and correct roll or yaw in the sense of the corresponding steering deflection until the oversteer condition is reached.

2. When restoring the glider's normal flight position, it must be possible to prevent a bank of more than 30° by normal use of the controls. The glider must not show any uncontrollable tendencies to go into a corkscrew.

3. Yaw must not have a significant effect on drag behavior.

UL2-VI § 201 (3) (explanatory notes)
Yaw up to 5 degrees must not have a significant effect on drag behavior.

4. The loss of height from the onset of the stall condition to the re-attainment of level flight must be determined using normal procedures and the maximum pitch after pitching to the horizon.

UL2-VI § 201 (4) (explanatory notes)
The loss of height during a stall is the difference between the height at which the stall occurred and the height at which level flight was again achieved.

5. If the glider (in winch takeoff configuration) comes out of straight flight at 1,2 x V_S1 by rapidly moving the control lever to an angle of approximately 30° above the horizon, the following descent must not be abrupt and must not be such that immediate recovery of the starting position is difficult.

6. Proof of compliance with the requirements of paragraphs 1 to 5 must be made under the following conditions:

a. flaps in all positions,
b. aerodynamic brakes retracted and extended,
c. landing gear retracted and extended,
d. glider is balanced at 1,5 x V_S1 (if equipped with balancing), a
e. in the case of a motor glider:

i. propeller in take-off position
ii. engine in idle mode
iii. engine in 90% max. take-off thrust mode.

UL2-VI § 203 Dragging in a corner

1. When stalling in a clean 45° banked turn, it must be possible to achieve normal level flight again without showing a tendency to an uncontrollable bank or to a spin. Demonstration of compliance with this requirement must be performed under the conditions specified in UL2-VI § 201(f), which correspond to the critical glider towing procedures. In any case, landing configurations with both applied and extended airbrakes must be tested.

2. The loss of altitude from the start of the stall to the resumption of level flight must be determined using normal procedures.

VI. Corkscrews

UL2-VI § 221 In general

1. There must be no tendency to an imperceptible transition into a corkscrew.

2. It must be possible to return the glider to normal flight from each point of motion in the spin after no more than one additional revolution using the recommended motions of the control systems to terminate the spin without exceeding the allowable speed or operational positive multiple.

UL2-VI § 221 (2) (explanatory notes)
The procedures which are considered normally as standard methods to terminate a corkscrew are set out as follows:

a. deviation of directional control against the direction of rotation,
b. a short delay until rotation stops,
c. release of altitude control,
d. rudder in the middle position and gently picking up the glider.

UL2-VI § 223 Characteristics of spiral flight

If the glider shows a tendency to go into steep spiral flight, the situations in which these tendencies are at risk must be determined. It must be possible to terminate this flight condition without exceeding the allowable speed or the positive operational load factor from the glider revolutions. The demonstration of compliance with this requirement must be carried out without the use of aerodynamic brakes.

UL2-VI § 251 Vibration and shaking

At all speeds up to VDF, there must be no excessive vibration on any part of the glider. In addition, in any normal flight configuration, including the use of aerobrakes, there must be no shake that would adversely affect glider control, cause excessive crew fatigue, or damage the support structure. A shake that warns of overstretching is acceptable within the stated limits.

 

TITLE C - STRENGTH

I. In general

UL2-VI § 301 Load

1. The strength requirements are determined using the operational load (the highest expected load in operation) and the numerical load (the operational load multiplied by the prescribed safety factor). Unless otherwise specified, the prescribed loads are "operating loads".

2. Unless otherwise stated, air and ground loads must be balanced with inertial forces, taking into account the individual weight items of the glider. These loads must be distributed to represent the actual conditions or to approach them on the safe side.

3. If deformation due to loading would substantially change the distribution of external or internal forces, such distribution in the deformed state must be taken into account.

UL2-VI § 303 Safety factor

1. Unless otherwise specified, a safety factor of 1,5 must be used.

2. The safety factor must be multiplied by an additional safety factor if:

a. there is uncertainty about the strength of the component (part),
b. loss of strength must be expected in time until replacement,

and

c. exact strength values ​​are not available due to unknown manufacturing and testing methods. The size of this additional safety factor, unless otherwise stated below, must be determined for each type separately. The required time until the replacement of these parts (parts) is indicated in the Operation Technical Manual.
d. the additional safety factor is mainly determined for:

i. every part that has clearance (does not apply to pressing) and is subject to impact stress or vibration,
ii. rudder hinges (except rolling and joint bearings).
iii. bearings (joints) in drawbar steering that are subject to angular movement (except rolling and ball bearings),
iv. bearings (joints) in cable management.

application	Additional factor of safety	The resulting factor fU
joints (shear fit) with play, shock stress or vibration	2,0	fU = 2,0 x 1,5 = 3,0
rudder hinges (except rolling and articulated bearings)	4,44	fU = 6,67
bearings (joints) in the tie rod. management	2,2	fU = 3,30
bearings (joints) in cable management	1,33	fU = 2,0
Castings	2,0	fU = 1,5 x 2,0 = 3,0
Fittings - valid for all fittings all fasteners pressing (for fixed mounting)	1,15	fU = 1,5 x 1,15 = 1,725
seat belts and seats	1,33	fU 1,5 1,33 x = 2,0

Interpretation of the use of additional factors for composite structures.

The safety factor f for composite structures is in the range of 1,5 - 2,25, that is, an increasing factor of 1 - 1,5.

The use of the increasing factor depends on:

• component or part to which it will be applied,
• accuracy of calculations and their reliability,
• submitted tests of samples of composite material and their results, and
• verification of production, control procedures and experience of the manufacturer.

The Technical Commission will decide on the use of the relevant safety factor in cooperation with the chief engineer and the expert opponent of the project. In the case of amateur constructions, the chief technician and the construction supervision technician will decide on the use of the coefficient.

UL2-VI § 305 Strength and deformation

1. The structure must be able to transfer operational loads without permanent deformations. Under all loads up to the operating load, the resulting deformations must not affect safe operation. This is especially true for control systems.

2. The structure must be able to withstand the numerical load for at least 3 seconds without failure. If the strength test is performed by a dynamic test simulating real load conditions, then this time limit does not apply.

UL2-VI § 307 Evidence of structural strength

1. Compliance with strength and deformation requirements according to UL2-VI § 305 must be demonstrated for all critical load cases. The theoretical proof of strength can only be recognized if the type of construction used, based on experience, guarantees that reliable results will be achieved by the calculation methods used. Otherwise, verification by strength tests must be carried out.

II. Flight loads

UL2-VI § 321 In general

1. The load factor is given by the ratio of the component of the resulting aerodynamic force, which acts perpendicular to the glider's flight path, to the weight of the glider. A positive load multiple is one at which the resultant aerodynamic force acts upwards.

2. Compliance with the flight load requirements of this Subpart C must be demonstrated for all practicable combinations of weight and center of gravity.

UL2-VI § 331 Symmetrical flight conditions

1. When determining the wing load under symmetrical flight conditions according to UL2-VI § 333 to UL2-VI § 345, the relevant balancing devices on the horizontal tail surfaces must be taken into account so that the resulting load, including the load from linear inertial forces, corresponds to the actual conditions or is on the safe side.

2. The increase in load on the horizontal tail surfaces during turns and gusts must be balanced by the forces from the angular acceleration of the glider so that the resulting load corresponds to the actual conditions or is on the safe side.

3. In determining the load that will occur under the prescribed conditions, it is assumed that an instantaneous multiple will occur due to a sudden change in the angle of attack while maintaining speed. Angular accelerations can be neglected.

4. The aerodynamic values ​​needed to determine the load must be supported by tests, calculations or estimated in a safe way:

a. In the absence of more accurate data, the value of the highest negative coefficient of the relationship for the standard type configuration can be equal to - 0,8.
b. If the overturning moment coefficient is C_mo less than ±0,025, then the C factor must be used for the wing and tail surfaces_mo with a value of at least ±0,025.

III. Flight envelope of operating multiples (Vn diagram)

UL2-VI § 333 In general

1. Compliance with the strength requirements of this Chapter must be demonstrated for all combinations of flight speeds and load multiples, located on the perimeter and inside the load envelope, composed of turning and gust loads specified in the paragraph. 2. and 3 of this point.

2. Reversal envelope.

Configuration:

Flaps in cruising position, air brakes engaged (see Figure 1).

Figure 1
Turnover envelope

3. Gust envelope

Configuration:

Flaps in cruise position (see Figure 2).

a. At design maneuvering speed V_B the glider must be able to withstand a positive (upward) and negative (downward) gust of 15 m/s acting perpendicular to the flight path.
b. At design speed V_D the glider must be able to withstand a positive (upward) and negative (downward) gust of 7,5 m/s acting perpendicular to the flight path.

Figure 2
Gust envelope

 

UL2-VI § 335 Design airspeeds

The following design speeds are equivalent speeds (EAS):

1. Design rotation speed V_A

where:

V_S1 = calculated stall speed at design maximum weight with flaps in cruising position and airbrakes applied.

2. Design airspeed with flaps extended V_F:

a. In all landing figures, the speed must not be V_F less than the greater of the following values:

i. 1,4 V_S1, where V_S1 is the calculated stall speed with flaps in cruising position and maximum weight,
ii. 2,0V_SF, where V_SF is the calculated stall speed with the flaps fully extended and at maximum weight.

b. For all positive flight figures, the speed must not be V_F less than 1,05 V_A, where V_A is defined in paragraph 1, i.e. that the flaps are in the cruise position.

3. Design speed V_B for strong gusts:

V_B must not be lower than 1,15V_A

4. Design speed V_T in aerofoil:

V_T must not be lower than V_A

5. Design speed at start with winch V_W:

V_W must not be lower than 1,5V_S1 according to UL2-VI § 335 1.

6. Design maximum speed V_D:

Design maximum speed V_D may be chosen by the proposer, but may not be less than:

Where:

m/S = surface load in kg/m² at design maximum weight,
cw_min = minimum glider drag coefficient.

UL2-VI § 335 (explanatory notes)

1. For flaps that can be used both in fast flight and in slow flight, the expression "flaps in neutral position" given in UL2-VI § 335 1. and UL2-VI § 335 2. is defined as such a position of the flaps that will occur if they are retracted from the maximum negative position by one third of the total range intended for the flight configuration.
2. For flaps that can only be used in slow flight, such as slot flaps, brake flaps, and other flaps that normally extend only in the positive direction, "flaps in neutral" means the fully retracted position or the maximum upper position.

UL2-VI § 337 Operating turnover multiples

Operating turnover multiples according to the turnover envelope (see Figure 1) must have the following values:

n1	+ 4,0
n2	+ 3,0
n3	- 1,5
n4	- 2,0

UL2-VI § 341 Gust multiples

1. If a more accurate analysis corresponding to the actual conditions is not available, the calculation of the multiple of the gust must be calculated from the relation

Where:

U gust speed [m/s]
V equivalent flight speed [m/s]
α slope of the lift line of the wing [radian]
g gravitational acceleration [m/s²]
S design area of ​​the wing [m²]
ρ₀ air density at H=0m [kg/m³]
m glider weight [kg]
K gust mitigating factor determined from the relationship:

Where μ is the relative mass ratio of the aircraft, which is calculated as

lm geometric mean chord of the wing [m]
ρ is the air density at a given height

It is not necessary that the value of n, which is determined by the above relation, be greater than:

UL2-VI §345 Loads with aerodynamic brakes and flaps extended

1. Load with aerodynamic brakes extended:

a. The structure of the glider, including aerodynamic brakes, must be able to withstand the most unfavorable combination of the following parameters:

Equivalent speed	VD (EAS)
Aerodynamic brakes	From retracted to fully extended position
Turnover multiple	From -1,0 to +3,0

b. It is assumed that the loading of the horizontal tail surfaces corresponds to the conditions of static equilibrium.

c. The effect of extending the aerodynamic brakes on the change in load distribution along the wing span must be considered.

2. Load with flaps extended

If the glider has flaps, the following maneuvering and gust load cases of the glider are considered:

a. With flaps (in all landing positions) and speeds up to V_F:

i. flight maneuvers up to a positive operational multiple of 3,
ii. positive and negative gusts of 7,5 m/s acting perpendicular to the flight path.

b. With flaps in flight positions ranging from the maximum positive position to the maximum negative position according to the maneuvering conditions of point UL2-VI § 333 1. and the gust conditions of point UL2-VI § 333 3., except that the following need not be taken into account:

i. a speed higher than that corresponding to the speed V_F for a given flap configuration,
ii. the maneuvering multiple corresponding to the points above the segment AD or below the segment GE in Figure 1.

3. Flap flaps to limit speed

If flaps are used as drag-increasing devices (aerodynamic brakes), they must meet the requirements of UL2-VI § 345 (a) in all flap positions.

4. If the glider is equipped with a device that limits flap loading automatically, the glider must be designed for such critical combinations of flap speed and position that this device allows.

UL2-VI § 347 Unsymmetrical flight conditions

The glider is assumed to be in non-symmetrical flight positions according to UL2-VI § 349 and UL2-VI § 351. Unbalanced aerodynamic moments relative to the center of gravity must be balanced by inertial forces in a manner that corresponds to actual conditions or is on the safe side.

UL2-VI § 347 (explanatory notes)

It is assumed that the glider will maintain its initial position after a steering deflection to induce yaw or yaw until the deflection-induced load increment reaches its maximum value.

UL2-VI § 349 Cloning conditions

The glider must be designed for yaw loads resulting from aileron deflections and from the speeds specified in UL2-VI § 455 in combination with a factor equal to at least two-thirds of the positive maneuvering factor prescribed in UL2-VI § 337.

UL2-VI § 351 Turning conditions

The glider must be designed for turning loads due to the force on the vertical tail surfaces in accordance with UL2-VI § 441 and UL2-VI § 443.

UL2-VI § 361 Engine bed load

1. The engine bed and its attachment must be designed for the following load cases:

a. operating torque load from the propeller, which corresponds to the take-off power and the respective propeller revolutions with the simultaneous application of 75% of the operating load from case A according to Chapter C, point UL2-VI § 333.
b. operational torque load from the propeller, which corresponds to the maximum continuous power and the respective propeller revolutions under the simultaneous application of the operational load from case A according to Chapter C, point UL2-VI § 333.
c. if the propeller has its own propeller bearing, the operating torque load from the engine can be used as the operating torque load from the propeller in paragraph a. and b.

2. For conventional piston engines with a direct ("hard") propeller drive, the operating torque from the engine used in paragraph 1 above is calculated by multiplying the mean (average) torque by the appropriate factor according to the following table:

	Two-stroke engine	Four-stroke engine
1 cylinder	6	8
2 cylinders	3	4
3 cylinders	2.5	3
4 cylinders	1.5	2
5 or more cylinders	1.33	1.33

Note: The term "hard" transmission means direct drive, toothed wheel or toothed belt drive, for other types of drive (e.g. centrifugal clutch) and non-conventional engines, the relevant factor must be consulted with the responsible authority.

UL2-VI § 363 Side load of engine bed

The engine bed and its mountings must be designed for a lateral load with a lateral service factor not less than one-third of the service factor from case A (1/3 n1).

UL2-VI § 375 Winglets

1. If the glider has winglets, then it must be designed for the following loads:

a. lateral load corresponding to the winglet's maximum yaw angle at V_A ,
b. gust load acting perpendicular to the winglet surface at V_B and V_D ,
c. mutual influence of the aerodynamic load on the wing and winglet,
d. operating load of the hands during ground operation of the glider, a
e. wing tip load according to UL2-VI § 501, if the winglet may contact the ground.

UL2-VI § 375 1. (explanatory notes)

For the wing, the influence of the winglet on the following quantities must be taken into account:

a. change in buoyancy distribution,
b. additional bending and twisting moment on the attachment points of the winglet, taking into account the aerodynamic and mass forces acting on the winglet,
c. inertia forces, a
d. the effect of drag on the twist of the wing

2. If a more accurate calculation method is not used, then the load can be determined as follows:

a. Winglet lift due to yaw angle at V_A:

Where:

C_lMax value of the maximum lift of the winglet profile
SW winglet area

b. Winglet lift in horizontal gust at V_B to V_D:

Where:

For a horizontal gust, the size of which is determined in UL2-VI § 333
a_W winglet airfoil slope [rad]
k gust coefficient according to UL2-VI § 443

The above load L_Wg need not be greater than

c. A hand load of 15 daN must be considered at the end of the winglet:

i. in the horizontal direction outwards and inwards parallel to the axis of the wing, a
ii. in a horizontal direction towards the front and back parallel to the axis of the trunk.

In addition, the mounting load according to UL2-VI § 591 must be considered if the winglets are not perpendicular to the plane of the wing.

IV. Control surface and control system

UL2-VI § 395 Load of driving routes

1. All parts of the main control system, including the stops and their supporting structure, must be designed for a load that corresponds to at least 125% of the calculated design hinge moments of the movable control surfaces under the conditions prescribed in UL2-VI § 415 to UL2-VI § 455. When determining the hinge moments, reliable aerodynamic values ​​must be used. The effect of auxiliary flaps must be taken into account. In no case must the load on any part of the system be less than 60% of the forces from the pilot according to UL2-VI § 397 when acting with hands or feet.

2. For the design values ​​of the forces of the pilot when acting on the hands or feet, it must be considered that they act on the relevant control lever or control pedal in the same way as in flight, and that it is brought into balance by the reaction forces at the point of attachment of the control levers of the control surfaces.

UL2-VI § 397 Loading by forces from the pilot

1. In addition to the requirements according to UL2-VI § 395 (1.), all control systems used for direct control of the glider around its longitudinal, transverse or vertical axis (main control system) and other control systems that influence the behavior of the glider in flight must , as well as the places for their fixing or support must be designed up to the stops (including the stops) for operational loads, which are indicated in the table.

Management	Acting force	Method of force introduction
	[tax]	[Requirement: Simple Link System]
Longitudinal steering	35	Pull and push on the control lever
Lateral steering	20	Side-to-side movement of the control stick
Directional control	90	Push the steering pedal forward
Aerodynamic brakes, spoilers, flaps	35	Push and pull on the hand controller
Towing hitch	35	Push with the hand controller

UL2-VI § 399 Dual control systems

Dual control systems must be designed for the following loads:

1. simultaneous action of both pilots in the same direction, a
2. simultaneous action of both pilots in the opposite direction, while it is assumed that both pilots exert 75% of the forces according to UL2-VI § 397 1.

UL2-VI § 405 Secondary management

Secondary control systems such as landing gear retract and extend systems, trim controls, etc. must be designed to withstand the maximum forces that the pilot can exert on their controls.

UL2-VI § 405 (explanatory notes)

Design base forces derived by hand or foot shall not be less than:

1. force exerted by hand on small wheels, handles, etc., which are controlled only by fingers or hand: P = 15 daN
2. the force exerted by the hand on the levers and wheels which are operated by arm strength without using body weight: P = 35 daN
3. the force exerted by the hand on the levers and wheels which are operated arm strength with support or using body weight: P = 60 daN
4. force derived by the leg force of the pilot in a seat with support (e.g. using a foot brake) P = 75 daN

UL2-VI § 411 Stiffness and deformation of control paths

1. The range of movement of the control surfaces or surfaces that the pilot can use in the cabin must not be dangerously reduced by the flexible deformation of the steering system under any flight conditions. If ropes whose tension is adjustable are used in the system, then the lowest value (tension) must be used to demonstrate compliance with all relevant requirements.

UL2-VI § 411 (explanatory notes)

1. As a fulfillment of the requirement of UL2-VI § 411, it can be used to demonstrate that, when loaded with a force according to the table, no part of the control system should be lengthened or shortened by more than 25%:

force (N)	Method of force introduction
120	Pull and push the handle
80	Move the handle to the side
150	Push the pedal

However, an extension greater than 25% is acceptable if flight tests demonstrate compliance with UL2-VI § 143 and UL2-VI § 629.

The proportional elongation is determined by the relation

D = 100 a/A

where

and – the movement of the control body in the cabin, if the rudder is blocked in the neutral position
A – movement of the control lever (pedal) from neutral to the extreme corresponding position

2. In the case of rope controls, the permissible tension of the ropes must be determined with regard to the resulting changes depending on the temperature (see UL2-VI § 689).

UL2-VI § 415 Load due to ground gust

The control system from the control surface to the stop, or if installed, to the locking device, must be designed for the service load based on the suspension moment, calculated from the relation

M_R = kxl_R xS_R xq

Where:

M_R operating rudder hinge moment [Nm]
l_R mean depth of the control surface behind the axis of rotation [m]
S_R the area of ​​the control surface behind the axis of rotation [m²]
q dynamic pressure corresponding to a speed of 50 km/h
k coefficient for the operating hinge moment in ground gust, which is given in the following Table 1:

Table 1

Control surface	k	Notes
Lateral steering	±0,75	Lateral control blocked in the middle position
Lateral steering	±0,50	Lateral steering fully deflected + moment on one, – moment on the second control surface
Height control	±0,75	Height control fully retracted (-) or fully suppressed (+) deflected or in a position where it can be blocked
Directional control	±0,75	Steering deflected fully to the right or left or locked in the middle position

V. Horizontal tail surfaces

UL2-VI § 421 Balancing load

1. The horizontal tail balance load is the load necessary to maintain the balance of the aircraft under any flight conditions without pitching accelerations about the transverse axis.

2. Horizontal tail surfaces must be designed for such balancing loads as will occur at any point on the turn envelope and at any position of the aerodynamic brakes and flaps in accordance with UL2-VI § 333 and UL2-VI § 345.

UL2-VI § 423 Rotating loads

The horizontal tail surfaces must be designed for the turn loads that can be expected in pilot-induced pitch turns at all speeds up to speed. spines of V_D.

UL2-VI § 423 (explanatory notes)
Loads shall be determined for sudden elevation rudder deflection, taking into account the following cases:

a. velocity V_A, full upward deflection
b. velocity V_A, full downward deflection
c. velocity V_D, one third of full upward deflection
d. velocity V_D, one-third of the full downward deflection.

In doing so, the following assumptions must be made:

a. The glider is initially in level flight and its position and flight speed do not change
b. Loads are balanced by inertial forces.

UL2-VI § 425 Gust loads

1. The horizontal tail surface must be designed for gust loads up to the values ​​specified in UL2-VI § 333 3.

2. If a more accurate, realistic analysis is not available, the forces acting on the horizontal tail surface must be calculated from the following relationship:

Where:

P load on the horizontal tail surface [N]
P_o horizontal tailplane balancing load acting on the horizontal tailplane before the gust load [N]
ρ_o air density at H = 0 m [kg/m³]
k_H gust coefficient (unless a more accurate, realistic analysis is available, the same value as for the wing can be used)
S_H horizontal tail surface area [m²]
α_H slope of the lift line of the horizontal tail surface [radian]
U gust speed [m/s]
V flight speed [m/s]
dε/dα derivative of the air stream skew at the location of the horizontal tail surface

VI. Vertical tail surface load

UL2-VI § 441 Rotating loads 

The vertical tail surface must be designed for the loads from turns that occur under the following conditions:

a. full rudder deflection at the higher of V speeds_A to V_T,
b. one-third full rudder deflection at speed V_D.

UL2-VI § 441 (explanatory notes)
For glider tail surfaces where the horizontal tail surface is located above the vertical tail surface, the tail surfaces and their mountings, including the rear of the fuselage, must be designed for the prescribed vertical tail surface loads and the yawing moment induced by the horizontal tail surface acting in the same direction.

If a more precise analysis is not available, for T-tail surfaces the induced pitching moment from yaw or deflection of the rudder can be determined from the relation:

Where:

M_R0 induced moment from the horizontal tail surface [Nm],
S_H horizontal tail surface area [m²],
b_H horizontal tail span [m],
β yaw angle [radian].

UL2-VI § 443 Gust loads

2. The vertical tail surface must be designed for side gusts up to the values ​​specified in UL2-VI § 333 3.

3. If a more accurate, realistic analysis is not available, the gust forces must be calculated from the relationship:

Where:

P_S vertical tail surface load in gust [N],
α_S vertical tail lift curve slope [radian],
S_S vertical tail surface area [m²],
V flight speed [m/s],
U gust speed [m/s],
k_S gust factor; a value of 1,2 can be used,
ρ_o air density at H = 0 m [kg/m³].

UL2-VI § 443 (explanatory notes)
For glider tail surfaces where the horizontal tail surface is located above the horizontal tail surface, the tail surfaces and their attachments, including the rear of the fuselage, must be designed for the prescribed vertical tail surface loads and for the yawing moment induced by the horizontal tail surface acting in the same direction.

If a more accurate analysis is not available, for T-tail surfaces the induced pitching moment from the gust load can be determined from the relation:

Where:

M_R0 induced moment from the horizontal tail surface [Nm],
S_H horizontal tail surface area [m²],
b_H horizontal tail span [m].

VII. Additional conditions for tail surfaces

UL2-VI § 447 Combined loading of tail surfaces

1. Provided that the glider is in maneuvering load conditions corresponding to point A or D of the turn envelope (depending on which conditions lead to a higher balancing load), the asymmetrical distribution of the balancing load of the horizontal tail surfaces must be combined with the load of the vertical tail surfaces according to UL2- VI § 441 so that the bending moment increases.

UL2-VI § 447 1. (explanatory notes)

1. If a more precise analysis is not available, the asymmetrical distribution can be determined by multiplying the air load on one side by a factor of (1+x) and on the other side by a factor of (1-x):

a. For point A of the turnover envelope, x = 0,34. For point D, x = 0,15.
b. The induced pitching moment of the T-tail may not be included in the unsymmetrical loading of the horizontal tail.

2. It must be assumed that 75% of the load according to UL2-VI § 423 (for horizontal tail surfaces) and according to UL2-VI § 441 (for vertical tail surfaces) is applied simultaneously.

UL2-VI § 449 Additional loading of butterfly tail surfaces

A glider with butterfly tail surfaces must be designed for a load where the gust acts perpendicular to one part of the tail surface at a speed greater than V_B.

VIII. Wings

UL2-VI § 455 Wings

The aileron must be designed for a load that corresponds to the following conditions:

a. maximum aileron deflection at speed V_A or V_T, whichever is higher, and
b. one third of full aileron deflection at speed V_D.

IX Ground load

UL2-VI § 471 In general

The operational ground load specified in this section is defined as the external load and inertial forces acting on the glider structure. In all specified ground load conditions, the external forces must be in balance with the inertial forces and moments so that the model physics match the actual conditions or be on the safe side.

UL2-VI § 473 Assumptions of ground load

1. The following requirements must be met for the maximum design weight.

2. For ground loads in this subsection, an operational landing impact factor at the glider's center of gravity of n=3 may be used. Alternatively, a value corresponding to a landing with a descending speed of 1,5 m/s can be used.

3. It can be considered that during the landing impact the lift of the wing balances the weight of the glider and acts at the center of gravity. The product of the ground forces can be equal to the inertial product minus one.

UL2-VI § 477 Arrangement of landing gear

Points UL2-VI § 479 to UL2-VI § 499 apply to gliders with a conventional landing gear arrangement. For unusual landing gear arrangements, it is necessary to check additional landing conditions, depending on the layout and design of the landing gear.

UL2-VI § 477 (explanatory notes)

In connection with the requirements of this point, a landing gear can be described as conventionally arranged if it consists of:

1. from a single wheel or a pair of wheels on a common axis under the fuselage or two, laterally located, separate wheels (with shock absorbers or without shock absorbers) located directly or approximately under the center of gravity of the glider, together with the nose wheel, or an auxiliary support (sled), located on bottom of the fuselage (the front auxiliary rest goes from the front of the fuselage to the main wheel(s), the rear section continues aft approximately below the trailing edge of the wing). The back rest can be replaced or supplemented with a suitable tail support (spur). Both supports can be replaced by suitable reinforcement of the hull structure.

2. from one flexible main strut on the bottom of the fuselage running from the front of the fuselage to a point approximately below the trailing edge of the wing. This rest can be supplemented with a tail rest or a wheel.

3. from the supports located at the ends of the wing.

UL2-VI § 479 Normal landing conditions

1. A normal landing is considered when the glider is in the following flight positions:

a. for gliders with a spur and/or spur wheel - in a normal horizontal position.
b. for a glider with a nose wheel - a position in which:

i. nose and main landing gear touch the ground at the same time, a
ii. the main landing gear wheels touch the ground and the nose landing gear is just off the ground.

2. Vertical load component of main landing gear P_VM must be determined from the conditions specified in point UL2-VI § 725.

3. Vertical load component of main landing gear P_VM acts simultaneously with the horizontal component of the load P_H backwards so that the resulting load acts at an angle of 30° from the vertical axis.

4. For gliders with a nose wheel, the vertical component P must be calculated_VN on the nose wheel, when considering the flight position according to paragraph 1. b) (i) of this point, according to the relationship below and must be combined with the horizontal component acting backwards according to point 3.

Where:

m glider mass [kg],
g gravitational acceleration [m/s²].

UL2-VI § 481 Landing on the stern landing gear

For the structural solution of the spur and its fastening to the supporting structure, including the tail surfaces with fixed balancing masses, the load of the spur in the case of landing on the stern landing gear (with the main landing gear just above the ground) must be determined in the following way:

Where:

P force on spur [N],
m glider mass [kg],
g gravitational acceleration [m/s²],
iy radius of inertia of the glider [m],
L distance of the spur from the center of gravity of the glider [m].

UL2-VI § 481 (explanatory notes)

If you cannot value i_y (radius of inertia) to determine in a more accurate way, the value can be used

i_y= 0,225 x L_r

In these cases, L corresponds_R total hull length without rudder. When designing the spur, in addition to the above-mentioned calculated vertical load of the spur, it is also necessary to consider the lateral load.

UL2-VI § 483 Landing on one wheel

In the arrangement of the main landing gear with two wheels located laterally (see UL2-VI § 477 of explanation 1.) under the conditions according to UL2-VI § 479 1. to 3. and 4. the load must also be introduced on each wheel separately, while it is possible to consider eventual limitation due to lateral inclination. If a more detailed analysis is not available, the operating kinetic energy can be calculated from the relation:

Where:

V_v descent speed = 1,5 m/s,
m glider mass [kg],
And gauge [m],
i_x radius of inertia of the glider [m].

UL2-VI § 485 Lateral load conditions

It is necessary to consider the effect of the lateral force on the main chassis (left and right) at the point of contact of the wheel or support (sled) with the ground, perpendicular to the axis of symmetry. The magnitude of this force is 0,3 P_v and acts simultaneously with half of the vertical load, specified in UL2-VI § 473.

UL2-VI § 497 Falling on a spur

1. If the center of gravity of an unloaded glider, with respect to the longitudinal direction, lies behind the plane of contact of the main landing gear with the ground, then the rear part of the fuselage, including the spur and tail surfaces, must be designed to withstand the load created in the event of a fall of the spur from a height when the glider is tilted to the highest possible forward position (the main landing gear is still on the ground) and from this height it is lowered to the ground.

2. If the center of gravity of the glider in all load conditions is located behind the point of contact of the main landing gear with the ground, then the requirement according to 1. does not apply.

UL2-VI § 499 Additional conditions for bow wheels

To determine the ground load of the nose wheels and their attachment, and assuming that the damper and tires are in the position corresponding to the static load, the following conditions must be met:

1. For forward loads, the additional load components on the axis must have the following magnitude:

a. a vertical load component of 2,25 times the static reaction of the wheel a
b. a forward load component of 0,4 times the vertical component.

2. For lateral loads, the operating components of the load at the point of contact of the wheel with the ground must have the following magnitude:

a. a vertical load component of 2,25 times the static reaction of the wheel, a
b. a lateral load component of 0,7 times the vertical component.

UL2-VI § 501 Landing with a spin

Appropriate measures must be taken to ensure that the load is transferred after the tip of the wing touches the ground. It is assumed that at the point of contact of the wing with the ground towards the rear, an operating load of T = 20 daN acts parallel to the longitudinal axis of the glider. The resulting turning moment must be balanced by the lateral force R on the stern spur / stern wheel or on the bow skid / bow wheel.

X. Emergency landing conditions

UL2-VI § 561 In general

1. Although the glider may be damaged in an emergency landing, it must be designed to protect each crew member under the following conditions.

2. The supporting structure must be designed so that each crew member has a good chance of protection from serious injury in a light emergency landing, with the correct use of harnesses, under the following conditions:

a. The crew member is exposed to independently acting numerical inertial forces, corresponding to the accelerations listed in Table 2

Table 2

Up	4,5 g
Forward	9,0 g
To the side	3,0 g
Down	4,5 g

b. The forward part of the fuselage should be designed to provide adequate protection to the crew under a numerical load equal to 4 times the weight of the glider (4g) directed rearward and upward at an angle of 45° to the longitudinal axis of the glider, acting on the most forward part of the nose of the fuselage that is suitable for introducing such a load.

3. A glider with retractable landing gear must be designed so that its construction protects each crew member during a landing with the landing gear retracted under the following conditions:

a. downward numerical inertial force corresponding to an acceleration of 3 g,
b. glider-ground friction coefficient equal to 0,5.

4. With the exception of the requirements specified in point UL2-VI § 787, the load-bearing parts of the structure must be designed in such a way that, under loads corresponding to the accelerations specified in paragraph 2.a) of this point, it can safely hold isolated masses that could injure a crew member when released under the conditions light emergency landing.

UL2-VI § 563 Load with rescue system

1. The strength support structure between the connection point of the rescue system support rope and the seat and the harnesses must be designed so that, in the event of the rescue system being put into operation, it will transmit the impact after deployment, which corresponds to the data of the rescue system manufacturer.

2. The effect of impact on the support structure of the glider after deployment of the ZS canopy must be considered.

3. The load on the rescue system is dealt with in Annex I of this regulation.

XI. Towing load

UL2-VI § 581 Aerovlek

1. It is assumed that the glider is initially in a position corresponding to steady level flight at a speed V_T and the load from the towing rope to the towing hitch acts in the following directions:

a. forward horizontally,
b. forward and upward in the plane of symmetry and at an angle of 20 ° from the horizontal direction,
c. forward and downward in the plane of symmetry and at an angle of 40 ° from the horizontal direction, a
d. horizontally forward and sideways at an angle of 30 ° from the plane of symmetry.

2. It is assumed that the glider is initially in the same position as specified in UL2-VI § 581 1. and the rope load is increased to 1,2 Q due to recoil_name.

a. The resulting increase in load from the rope must be balanced by the sliding and rotational inertial forces. These additional loads must be added to those incurred according to UL2-VI § 581 1.
b. Q_name must not be less than 1,3 times the load corresponding to the maximum weight of the glider.

UL2-VI § 583 Taking off with a winch, behind a motor vehicle

1. It is assumed that the glider is initially in a position corresponding to steady level flight at a speed V_W, while the load of the rope on the towing hitch has a forward and downward direction in the range of an angle of 0 ° to 75 ° from the horizontal position

2. The load from the towing rope must be determined as the smaller of the following two values:

a. 1,2Q_name according to UL2-VI § 581 2. , or
b. forces at which equilibrium is achieved, either:

i. full deflection of the elevator up, or
ii. maximum lift of the wing.

It is assumed that horizontal mass inertial forces can be used to supplement the balance of horizontal forces.

3. It is assumed that the load on the rope under the conditions according to UL2-VI § 583 1. suddenly increases to a value of 1,2 Q_name. (see UL2-VI § 581 2.). The additional load resulting from this situation must be balanced by the sliding and rotational inertial forces of the glider.

UL2-VI § 585 Strength of towing hitch attachment

1. The hitch must be designed for a service load of 1,5 Q_name (see UL2-VI § 581 2.) when force is applied in the directions defined in UL2-VI § 581 and UL2-VI § 583.

2. The towing hitch must be designed for operational loads from the maximum weight of the glider, which act at an angle of 90° to the plane of symmetry of the glider.

UL2-VI § 587 Starting with a rubber rope

1. For a glider standing on the ground and ready for take-off, the rubber rope must be considered as a forward force acting on the take-off hanger, which corresponds to 1,2 times the maximum take-off weight and which acts in any direction below the horizontal plane between 0° and 20° .

2. The same tensile force as according to UL2-VI § 587 1. acts as a reaction force towards the back on the clamping device.

3. A force corresponding to 90 times the maximum flight weight acts on the launch hinge in a horizontal plane with a lateral angle of 0,5° to the longitudinal axis of the aircraft.

XII. Other loads

UL2-VI § Loads during wing assembly

The service value of the mounting load is determined as twice the reaction at the wing end rib in the positive and negative directions that occurs when either the split wing is simply supported under the root and end ribs or the continuous wing is supported under both end ribs. This load represents the glider assembly load and is assumed to be introduced at the end of the wing and balanced by the reactions and moments acting on the wing root.

UL2-VI § 593 Handling loads on the horizontal tail surface

At each end of the horizontal tailplane, consider the operating hand handling load:

a. in the vertical direction, a
b. in the horizontal direction parallel to the longitudinal axis,

which corresponds to 5% of the design maximum take-off weight, but at least 10 daN.

UL2-VI § 597 Loads with solitary substances

The fastening of all single masses that are part of the glider equipment must be designed to carry all loads corresponding to the maximum design multiples of flight and ground loads.

 

TITLE D - DESIGN AND CONSTRUCTION

UL2-VI § 601 In general

The suitability of any structural part or part, with the use of which there is no previous experience and which in terms of strength has a significant effect on the safety of operation, must be verified by tests.

UL2-VI § 603 Materials

The suitability and durability of materials used for parts whose failure could endanger safety must:

a. be proven on the basis of previous experience or tests, a
b. correspond to the approved specifications, which guarantee their strength and other properties that are used in the design.

UL2-VI § 605 Production methods

The production methods used must continuously guarantee the production of the primary supporting structure without defects. If manufacturing processes (eg gluing, spot welding, heat treatment or plastic processing) require precise control for this purpose, this activity must be carried out according to approved manufacturing processes. Non-conventional production methods must be proven by appropriate tests.

UL2-VI § 607 Protection of connections

Approved securing devices and securing procedures must be used to secure all fasteners in the primary structure, steering and other mechanical systems important to the safe operation of the glider. In particular, self-locking nuts must not be used for pivots that rotate in service, unless an additional locking element is used, which, however, must not use friction alone for insurance.

UL2-VI § 609 Construction protection

Each part of the supporting structure must:

1. be sufficiently protected during operation against harmful effects or reduction of strength due to any causes, including weathering, corrosion and abrasion,

2. have suitable means for ventilation and drainage.

UL2-VI § 611 Inspections

The design of the glider must allow for inspections (including inspections of the main support structure and control systems), thorough inspection, repair and replacement of each part, adjustments for proper fit and proper operation, lubrication and maintenance.

UL2-VI § 612 Assembly and disassembly

The design of the glider must have such properties as to prevent damage or permanent deformation during assembly and disassembly by untrained helpers, especially where such damage would not be clearly detectable. Incorrect assembly must be prevented by appropriate design measures. Proper assembly of the glider must be easy to check.

UL2-VI § 613 Strength static values ​​and calculated values

1. The strength properties of the materials used must be documented by a sufficient number of tests so that the calculated values ​​can be determined on the basis of statistical data.

2. The design values ​​must be chosen so that the probability of insufficient strength of any part of the supporting structure, including considering the dispersion of material properties, is very low.

UL2-VI § 613 2. (explanatory notes)

Material specifications need to be established separately as part of the certification process or need to conform to published standards. When determining the design numerical values, the basic material values ​​may be changed and/or extended by the designer if the method of production (e.g. with regard to the type of construction or deformation), machining or subsequent heat treatment needs to be taken into account.

3. If, under normal operating conditions, a temperature that has a significant effect on strength is reached on the strength-bearing element or on the primary bearing structure, this effect must be taken into account.

UL2-VI § 613 3. (explanatory notes)

A temperature of up to 54 °C is considered a normal operating temperature for the structure.

UL2-VI § 619 Increasing factors

1. The safety factor prescribed in UL2-VI § 303 must always be multiplied by the appropriate combination of increasing factors determined in UL2-VI § 621 to UL2-VI § 625, UL2-VI § 657, UL2-VI § 693 and UL2-VI § 619 1.

UL2-VI §619 1. (explanatory notes)

For increasing combinations of safety factors, all of the following, corresponding factors that come into consideration for the specified part, must be included:

1. coefficient for castings derived according to UL2-VI § 621,

2. the highest of the special coefficients prescribed in UL2-VI § 623, UL2-VI § 625, UL2-VI § 657, UL2-VI § 693 or UL2-VI § 619 2. , and

3. two-hinge-factor prescribed in UL2-VI § 625 5.

2. For each part of the primary supporting structure that is not covered by points UL2-VI § 621 to UL2-VI § 625, UL2-VI § 657 and UL2-VI § 693, but whose strength

a. is uncertain,
b. may deteriorate in service before normal replacement, or
c. exhibits significant variance due to uncertainties in the manufacturing process or during controls, the safety factor must be chosen so that failure of the part as a result of inappropriate strength is unlikely.

UL2-VI § 621 Safety factors for castings

For castings whose strength will be proven by at least one static strength test and for which only optical inspection is used, a safety factor of 2,0 must be used. This factor may be reduced to a value of 1,25 if the reduction is verified by tests on at least three casting samples and if these castings as well as other manufactured castings are optically and radiographically inspected or are inspected by other non-destructive testing methods (NDT) of the same level .

UL2-VI § 623 Safety factor for storage

1. For connections using bolts or pins, a factor of 2,0 must be used with regard to:

a. influence of relative movement during operation, a
b. shocks or vibrations caused by play (looseness of bearing).

2. Hinges of control surfaces and connecting elements of the control system, which have the safety factors prescribed in UL2-VI § 657 and UL2-VI § 693, already fulfill the conditions of paragraph (a).

UL2-VI § 625 Coefficients for connections

The following applies to all joints (connecting parts used to connect one structural element to another):

1. For all joints, the strength of which is not proven by a strength test for operational and numerical loads, during which the actual stress conditions of the joints with the environment were simulated, an increasing factor of at least 1,15 must be used for

a. all elements of the connection,
b. all connecting parts, a
c. all storage of interconnected elements of the structure.

2. The joint factor does not need to be used for joints that are supported by extensive test results (e.g. continuous sheet metal joints, welded joints and bolted joints in wood).

3. An integral joint is considered a joint up to the point where the typical cross-section of the affected structural element is reached.

4. By calculation, test or both, it must be proven that the fastening of the seat, as well as the lap and shoulder harnesses to the supporting structure will transfer the load of inertial forces according to UL2-VI § 561 multiplied by an increasing factor of 1,33.

5. If only two bearings are used on an individual control surface, flap or aerodynamic brake, an increasing factor of 1,5 must be used for these bearings and for the structural elements that connect them to the primary support structure.

UL2-VI § 627 Fatigue strength

The primary support structure of the glider shall, as far as possible, be designed and constructed to exclude areas of high stress concentrations where variable stresses exceeding the fatigue limit may occur in normal service.

UL2-VI § 629 Flutter

1. The glider must at least V. in all configurations and at all permissible speeds_D exhibit resistance to flutter, divergence and control reversal. In the range of permissible speeds, the glider must have sufficient damping so that the aeroleastic oscillations die out quickly.

2. Proof of compliance with the requirements of paragraph 1 must be made as follows:

a. using a ground aeroelastic test including analysis and assessment of the determined oscillations and frequencies in order to determine flutter-inducing conditions, or using

i. numerical methods with regard to the occurrence of a critical speed in the range up to 1,2 V_D and
ii. by another approved procedure.

b. systematic flight tests to induce flutter in flight at speeds up to V_DF. These tests shall demonstrate that sufficient damping is available and that there is no rapid decay of damping when approaching V_DF.
c. flight tests at a speed approaching V_DF , which will sufficiently prove that

i. the effectiveness of steering around all three axes does not decrease in an unusually rapid manner, a
ii. there are no signs of impending divergence of the wing, tail surfaces and fuselage.

UL2-VI § 629 2. (explanatory notes)

For gliders whose V_D is not greater than 170 km/h, the approval authority may decide that a license is not needed according to UL2-VI § 629 2. a).

I. Control surfaces

UL2-VI § 655 Development

1. Movable control surfaces must be arranged so that there is no restriction between the control surfaces to each other or to other fixed elements of the structure, if one surface is held in any position and the others move through their entire range of deflections. This requirement must be met:

a. at operating load (positive or negative) for all control surfaces and in the entire range of their deviations a
b. during operational load of the glider's supporting structure, with the exception of the control surfaces.

2. If an adjustable stabilizer is used, it must be equipped with stops that limit the range of its adjustment to ensure safe flight and safe landing.

UL2-VI § 657 Rudder hinges

1. Hinges of control surfaces, except for ball and roller bearings, must have a safety factor of 6,67 due to the numerical strength of the softest material used as a bearing.

2. For ball or roller bearings, their nominal load must not be exceeded.

3. The hinges of the control surfaces must have sufficient strength and stiffness when loaded with forces parallel to the axis of rotation.

UL2-VI § 659 Mass balancing

Fastenings and surrounding structures for local mass balances used on rudders shall be designed for the following inertial loads:

a. 24 g perpendicular to the plane of the rudder surface
b. 12 g forward and backward
c. 12 g parallel to the axis of the rudder

II. Control systems

UL2-VI § 671 In general

Each control must work easily enough, smoothly in the right sense so as to ensure its safe function.

UL2-VI § 675 Stops

1. Each control system must have stops that safely limit the range of deflection of each moving aerodynamic surface controlled by that control system.

2. All stops must be located so that their wear, play, or adjustment of the steering system will not adversely affect the glider's handling characteristics by changing the range of motion of these positions.

3. Each stop must withstand loads that correspond to the design conditions for the control system.

UL2-VI § 677 Balancing

1. Provisions must be made to prevent accidental, incorrect or sudden balancing action. There must be a device near the trim control that indicates to the pilot the direction of movement of the trim control and its effect on the movement of the glider. In addition, a device must be provided to indicate to the pilot the position of the balancer with respect to its range of adjustment positions. These devices must be visible to the pilot and must be designed and located to prevent confusion.

2. Steering of auxiliary rudders shall be self-locking, except that the rudder is sufficiently balanced and no dangerous tendency to flutter appears. The self-locking control of the auxiliary rudders must have sufficient rigidity and reliability in the part from the auxiliary rudder to the connection of the self-locking member to the supporting structure of the glider.

UL2-VI § 679 Locking device in the control system

If a device is used that serves to block the glider control system on the ground, a device must be used that:

a. clearly warns the pilot if the blocking device is in operation, a
b. prevent the blocking device from being activated in flight.

UL2-VI § 683 Functional tests of control systems

Functional tests must prove that the system designed for the load according to UL2-VI § 397 does not

a. blocking / blocking,
b. excessive friction, a
c. excessive deformation if steering is controlled from the cab.

UL2-VI § 685 Structural parts of the control system

1. Each structural part of the control system must be designed and constructed to prevent blocking, chafing and restriction of movement caused by crew members, loose objects or frozen moisture.

2. There must be means in the cabin to prevent foreign objects from entering places where they could cause jamming in the system.

3. Measures must be implemented in the control system to prevent the contact of ropes or tie rods with other parts of the structure.

4. All parts of the steering system must be designed or clearly and permanently marked in such a way that the risk of incorrect assembly, which could result in a malfunction of the steering system, is unlikely.

UL2-VI § 687 Springs

The reliability of the use of any spring elements in the control system must be demonstrated by tests in which actual operating conditions are simulated such that spring failure does not cause flutter or other dangerous flight characteristics.

UL2-VI § 689 Ropes and rope systems

The following requirements apply to ropes and rope systems:

1. Each rope system must be designed in such a way that there are no dangerous changes in the tension of the ropes in the entire range of deviations in operating conditions, even in the event of expected changes in temperature and humidity

2. All rope guides, pulleys, ends and tensioners must be visually inspected. Compliance with this requirement may not be required if it can be demonstrated that there will be no impairment of the airworthiness of these parts during the approved period of operation.

3. Each type and size of pulley must correspond to the rope for which the pulley is used. Each sheave must have a tight cover to prevent the rope from slipping off the sheave or getting stuck if the rope is loose. Each pulley must lie in the plane of the rope in front of and behind the pulley so that the rope does not rub against its edge.

explanations to point 3.

The inner diameter of the guide groove of the pulley should not be less than 300 times the diameter of the individual wire of the rope.

4. Guides must be installed so as not to change the direction of the rope by more than 3°, except where it is shown by test or experience that a greater change in direction is permissible. The radius of curvature of the line must not be less than the radius of the sheave for the same rope.

5. On all parts that make an angular movement, tensioners must be connected so that they can be freely adjusted in the entire range of deflections.

UL2-VI § 693 Joints

Joints in steering systems with rods that carry out angular movement (except those with ball or roller bearings) must have a safety factor of at least 3,33, taking into account the strength of the softest material used as a bearing. This factor of safety may be reduced to a value of 2,0 for connections in the cable management system. For ball or roller bearings, their permissible nominal load capacities must not be exceeded.

UL2-VI § 697 Control of flaps and aerodynamic brakes

1. Each flap control must be designed so that flaps deflected to any position in which flight performance requirements are demonstrated will not change their position spontaneously when the control is secured or, unless it is demonstrated that such movement is not hazardous.

2. Control of flaps and aerodynamic brakes must be designed in such a way that it cannot be unintentionally extended or rearrangement. The applied control forces and rate of adjustment must not be so great at any permissible speed as to affect the operational safety of the glider.

3. Aerodynamic brakes or other glider drag-increasing devices shall comply with the following:

a. If the device is divided into several parts, these parts must be controlled by a single controller.
b. It must be possible to eject the device at any speed up to 1,05V_NE, without damaging the supporting structure, and retract at any speed up to V_A with a hand force not exceeding 20 daN.
c. The time required to extend and retract the device must not exceed 2 seconds.

UL2-VI § 699 Flap position indicator

A device must be located near the flap control that shows the pilot the current position of the flaps during their movement and after the movement has ended.

UL2-VI § 701 Connecting flaps

The movement of the flaps on opposite sides of the plane of symmetry of the glider must be synchronized by mechanical linkage, unless it has been demonstrated that the glider has safe flight characteristics even when the flaps are retracted on one side and extended on the other side.

UL2-VI § 711 Trip mechanism

1. Towbars used for winch takeoffs must be designed to automatically disengage the towline when the glider passes the towline.

2. The suitability of the towing hitch used must be proven.

3. It must be avoided as much as possible that screws or other protrusions on the switch itself or the surrounding supporting structure, including the chassis, could catch the towing rope or its parachute.

4. It must be shown that the force Q_name in each direction required to close the circuit breaker (see UL2-VI § 583) does not exceed the value specified in UL2-VI 143 3. and that the circuit breaker functions flawlessly under all conditions.

5. The range of movement of the release lever in the cockpit must not exceed 120 mm, including free travel.

6. The release lever in the cockpit must be arranged and designed so that a force can be easily developed according to UL2-VI § 143 3.

7. Easy visual inspection of the tripping mechanism must be provided.

UL2-VI § 713 Towing hitch

Depending on the launch(s) for which the type certificate is requested, the glider must be equipped with one or more towbars that meet the following conditions:

1. Towing hitches to be used for air towing:

a. must be located so that the probability of unobserved shutdown is as low as possible, a
b. must be placed on the fuselage as far forward as possible so that the probability of dangerous uplift during aerofoil is as small as possible and that under the conditions according to UL2-VI § 581 (a) (3) a tilting moment in the sense of "heavy on the head" occurs on the glider , whose angle, however, must not be greater than 25°.

2. Towing slings to be used for take-off by winch or motor vehicle must be equipped with a device that will automatically release the tow line in the event that the glider flies over the winch or tow motor vehicle.

3. If more than one towing hitch is installed, their controls must be designed so that all are released simultaneously.

III. Landing gear

UL2-VI § 721 In general

1. The glider must be designed in such a way that even when landing on an unprepared soft surface there is no danger to the crew members.

2. If the glider is equipped with a retractable undercarriage, it must be designed so that it can land normally even with the undercarriage retracted.

3. Wheels, skis and spurs and their attachments must be designed in such a way as to minimize the possibility of the towing rope catching on these structural elements.

4. If the glider's main landing gear consists of one or more wheels, the glider must be equipped with a mechanical braking device, e.g. a wheel brake.

5. The stern spur must be equipped with a shock-absorbing device.

UL2-VI § 723 Shock absorption

The ability to adequately absorb impacts must be demonstrated by testing.

UL2-VI § 723 (explanatory notes)

If the damping performance is not significantly affected by the spring rate, static tests may be performed. If a significant effect is expected, dynamic tests must be performed.

UL2-VI § 729 Retractable undercarriage mechanism

1. Each retractable landing gear mechanism and the supporting structure in which it is incorporated must be designed for maximum flight multiples with the landing gear retracted.

2. Retractable undercarriages must be shown to be able to be retracted and extended without difficulty up to the maximum V-undercarriage extension speed_LO.

3. A glider with a retractable undercarriage that is not manually controlled mechanically must have an auxiliary device for extending the undercarriage.

UL2-VI § 731 Wheels and tires

The static load rating of each wheel must meet or exceed the greater of the applied ground load or static load requirements. With double or tandem landing gear, each wheel must carry 70% of the maximum take-off weight.

IV. Cabin layout

UL2-VI § 771 Cab - general

1. The cockpit and its equipment must allow each pilot to perform his tasks without excessive concentration or fatigue.

2. Devices must be used that enable safe fixing of weights in the glider according to point UL2-VI § 31 2.

UL2-VI § 773 View from the cabin

Each cockpit must be designed to avoid glare and reflections that would limit the pilot's view and must be designed to:

a. the pilot's view from the cabin was sufficiently clear, clear and undistorted for safe control of the glider, a
b. each pilot was protected against the weather. Rain must not excessively affect the pilot's view of the flight path during normal flight and during landing.

UL2-VI § 773 b. (explanatory notes)

Fulfillment of the requirement in UL2-VI § 773 b. can be achieved by a corresponding opening in the cabin glazing.

UL2-VI § 775 Protruding signs and windows

1. Glazing and windows must be made of material whose fragments cannot cause serious injury.

2. The front and side parts of the glazing must have a light transmittance of at least 70% and must not significantly change the natural colors.

UL2-VI § 777 Controls and controls in the cab

1. All controls and controls in the cab must be arranged so that they can be operated comfortably and prevent confusion and inadvertent operation.

2. Controls and controls in the cockpit must be located and arranged so that the pilot can achieve full deflection in the seat and with lap and shoulder harnesses in use. Neither his clothing (including winter clothing) nor the structural elements of the cabin may prevent him from doing so

3. In gliders with dual controls, the following secondary controls and controls must be reachable from both seats as a minimum:

a. tow rope switch
b. aerodynamic brakes
c. flaps
balancing d
e. a device for opening and dropping the cabin cover
f. control mechanism of the rescue device
g. engine intake

UL2-VI § 777 d. (explanatory notes)

Double balancing shall not be required if it is demonstrated that at the most unfavorable position of the elevator balance surface the steering forces are sufficiently small and that no steering difficulties arise.

UL2-VI § 779 Sense of movement and action of control elements and controllers in the cabin

Cockpit controls and controls shall be designed to operate as follows:

Control and control element	A sense of movement and effect
Lateral steering	right (clockwise) right wing down
Height control	upwards to raise the nose of the fuselage
Directional control	right pedal forward for hull bow to right
Balancing	corresponding to the movement of the controller
Aerodynamic brakes	pull: the brakes extend
Flap flaps	drag: the flaps extend or fold down
Disconnecting the tow rope	pull: the rope disconnects
Control mechanism of the rescue device	drag: putting into action

UL2-VI § 780 Color marking and position of control elements and controls in the cabin

Controls and controls must be labeled and arranged as follows:

Control element	Color	Location
Disconnecting the tow rope	yellow	For left hand operation
Aerodynamic brakes	Blue	For left-hand control or in the case of a two-seater glider between the pilots' seats
Balancing (for longitudinal balancing only)	Green	Preferably for left hand control
Lever for opening the cabin cover	white	Not determined
Overlay drop lever (if used)	Red	It is not specified, it must be easily accessible
Other controls	Clear markings, but not yellow, blue, green, white, red or yellow/black
Control mechanism of the rescue device	Red	It must be easily accessible

If the same lever is used for both opening and dropping the cabin cover, it must be marked in red.

UL2-VI § 781 The shape of the levers of the control elements in the cabin

The towing rope release lever must be designed in such a way that LA 20daN release force can be applied even with gloves on.

UL2-VI § 785 Seats and safety belts

1. Each seat and its fastening to the supporting structure must be designed for the weight of the crew member according to UL2-VI § 25 1. a. and for maximum load multiples that correspond to the expected flight and ground loads including the emergency landing conditions specified in UL2-VI § 561.

2. Each seat and its attachment to the supporting structure must be adapted to transfer the reaction forces from the loaded defined in UL2-VI § 397 2.

3. The seats, including the upholstery, must not deform under load during flight in accordance with UL2-VI § 581 and UL2-VI § 583 in such a way that the pilot cannot safely reach the control and control elements or their incorrect use may occur.

4. Each glider seat must be designed so that each crew member can sit comfortably.

5. The strength of safety belts must not be lower than that which corresponds to the numerical load from flight and ground cases, as well as from emergency landing conditions according to UL2-VI § 561 2., taking into account the geometry of the arrangement of belts and the seat.

6. Each safety belt must be designed to hold the pilot safely in the original position (sitting or lying down) under the action of all accelerations that may occur during operation.

UL2-VI § 786 Protection against injury

1. Fixed parts of the strength structure or attached parts of the equipment must be upholstered, if necessary, to protect the occupants from injury in light emergency landing conditions.

2. Parts of the strength structure must be constructed or arranged so that injury to a crew member under the conditions defined in UL2-VI § 561 2. b) is extremely unlikely.

UL2-VI § 787 Luggage compartment

1. Each baggage compartment must be designed for the maximum load weight shown on the label and for the critical load distributions at the corresponding largest multiples that may arise in flight and ground load cases.

2. The luggage compartment must be arranged in such a way that the occupants of the cabin are protected from injury that could be caused by the movement of the contents of the luggage compartment during emergency landing conditions according to UL2-VI § 561.

UL2-VI § 807 Emergency exit

1. The pilot's cabin must be equipped in such a way that, in the event of danger, it is possible to leave it quickly and without problems.

2. A simple and easy-to-use opening system must be available for a closed cabin. The system must work quickly and be designed so that it can be operated by any person strapped into a seat in the cabin, and it must also be operable from outside.

UL2-VI § 809 Rescue system

The conditions for the rescue system are listed in Annex I of this regulation.

UL2-VI § 831 Ventilation

The cabin must be sufficiently ventilated under normal flight conditions.

UL2-VI § 857 Electrical grounding

1. If the glider is equipped with a winch or motor vehicle for take-off, there must be an electrically conductive connection between the metal parts of the towing hitch and the control lever.

2. The connection must be made with a copper conductor, with a cross-sectional area that must not be less than 1,33 mm².

UL2-VI § 881 Handling on the ground

Adequate means of safe transport and ground handling of the glider must be available.

UL2-VI § 883 Distance from the ground

1. If the edge of the wing touches the ground, the distance between the tail surfaces must not be less than 0,10 m.

2. If the edge of the wing touches the ground, the fully down deflected wing must not touch the ground.

UL2-VI § 885 Overlays

Removable covers must be well fixed to the structure.

 

TITLE E - PROPULSION SYSTEM

UL2-VI § 901 Definition and development

1. The applicant must demonstrate that each combination of engine, exhaust system and propeller on the airplane for which the airworthiness certificate is being carried out is compatible with that airplane, works satisfactorily and operates safely within the specified conditions.

2. The propulsion system includes all parts which:

a. are necessary to derive forward thrust, a
b. have an effect on the safety of the drive unit.

3. The propulsion unit must be designed, arranged and built in such a way that

a. safe operation was ensured,
b. was accessible for necessary inspections and maintenance, a
c. the installation regulations of the engine manufacturer were followed.

Note to paragraph 3.a:

A test run of the complete propulsion system lasting at least 3 hours will be recognized as a certificate. First, the engine must run for 1 hour at 75% of maximum continuous power. Then it is necessary to proceed according to the following program:

• Start and stop 10 times, start and idle for 5 minutes
• 5 minutes full power
• 5 minutes of cooling at low idle speed
• 5 minutes full power
• 5 minutes of cooling at low idle speed
• 15 minutes 75% continuous power
• 5 minutes of cooling at low idle speed
• 15 minutes full power
• Switch off the engine and let it cool down, repeat the program. At the same time, there must be no obvious damage to any part of the drive system or any of its components.

UL2-VI § 902 Gliders with retractable engines or propellers

Powered UL gliders with retractable engines or propellers must comply with the following requirements:

a. Insertion and extraction must be possible without risk of damage without requiring extraordinary skill or effort or excessive time.
b. It must be possible to secure the insertion (extraction) mechanism in extreme positions.
c. Openable covers must not obstruct insertion / extension and must be secured against accidental opening.

UL2-VI § 905 Propellers

1. The propeller must meet UL 2 Title J specifications.

2. Engine power and propeller shaft speed must not exceed the limits for which the propeller is certified or approved.

UL2-VI § 903 Motors

The provisions of this article apply to reciprocating engines which are designed and built in the usual way. The regulations are used for piston engines for ultralight aircraft.

UL2-VI § 925 Propeller safe distance

For an uncovered propeller, the safe distance at maximum weight, worst center of gravity and worst blade setting must not exceed the following values:

1. Ground clearance: at least 170 mm between the propeller and the ground (for each nose landing gear airplane) or 230 mm (for each spur landing gear airplane). In doing so, the landing gear must be statically compressed and the aircraft is either in the normal horizontal take-off position or in the taxiing position, whichever position is more critical. In addition, a safe distance must be maintained in the horizontal position at take-off if:

a. the critical tire is completely free of pressure and the relevant chassis strut is statically loaded, or
b. the critical undercarriage strut is at stop and the corresponding tire is statically loaded.

2. Distance from other parts of the aircraft:

a. The smallest radial distance of 25 mm between the end of the propeller blade and the adjacent parts of the aircraft, plus the additional radial distance that is necessary to dampen harmful vibrations (pay special attention to the springing of the elastic hangers).
b. At least 13 mm longitudinal distance between propeller blades or their fairings and other parts of the aircraft.
c. A safe distance between other rotating parts of the propeller or propeller hub (including its cover) and other parts of the aircraft must be maintained under all operating conditions.
d. Distance from persons on board.

There must be sufficient distance between the propeller and the person(s) on board so that the person on board who is strapped to the seat cannot come into contact with the propeller during careless operation.

II. Fuel system

UL2-VI § 951 In general

1. Each fuel system must be designed and arranged to safely provide such fuel flow and pressure as are intended for proper engine operation under all normal operating conditions.

2. Each fuel system must be arranged so that fuel can be drawn from only one tank to supply the engine, unless the air spaces of the tanks are interconnected so that the tanks are emptied simultaneously.

The fuel system must be constructed in such a way that it cannot be blocked by generated fuel vapors.

UL2-VI § 955 Fuel flow

1. Fall system.

The fuel flow during auto-filling (both from the main and reserve stores) must be 150% of the fuel consumption at maximum engine take-off power for each engine.

2. System with fuel pump.

The filling amount of fuel in each filling system (both from the main and from the reserve supply) must be 125% of the fuel consumption at the specified maximum take-off power of the engine.

UL2-VI § 959 Inexhaustible quantity of fuel

The inexhaustible amount of fuel must be determined for each tank as the amount at which the first signs of fuel failure occur under the most unfavorable conditions for such fuel supply during take-off, climb, approach and during landing. This amount must not exceed 5% of the tank volume.

UL2-VI § 963 Fuel tanks - General

1. Each fuel tank must withstand without failure the vibrations, inertial forces, hydrostatic load and external forces acting on it during operation.

2. If "spillover" of fuel in the tank can substantially change the position of the center of gravity of the airplane, measures must be taken to reduce the "spillover" to an acceptable level.

UL2-VI § 965 Tests of fuel tanks

Each fuel tank must withstand a pressure of 0,01 MPa without damage or leakage.

UL2-VI § 967 Fuel tank installation

1. Each fuel tank must be secured in such a way as to prevent concentrated loading caused by the fuel's own weight. In addition:

a. a soft spacer must be placed (if necessary) between the tank and its mounting to prevent chafing of the tank, and
b. the materials that are used to attach or cover the attachment must not be absorbent, or must be modified in such a way as to prevent the absorption of fuel.

2. Each space in which the tank is built must be ventilated and equipped with drainage to prevent the accumulation of flammable liquids or vapors in it. Every space adjacent to the space in which the tank is built must also be well ventilated and equipped with drainage.

3. No fuel tank may be located where it could be hit in the event of an engine fire.

4. It must be proven that the location of the tank installation site will in no way limit the operation of the aircraft or the freedom of movement of the persons on board, and that the escaping fuel cannot directly affect the persons on board.

5. Damage to the structure due to a hard landing in which the landing gear load exceeds the required numerical value, but the total load does not exceed the values ​​for an emergency landing, must not lead to the destruction of the fuel tank or fuel lines.

UL2-VI § 971 Fuel tank drain sump

1. Each fuel tank, if permanently installed, must have a drainable sump effective in all normal positions on the ground and in flight, the volume of which is either 0,10% of the tank volume or 120 cm³ (the larger value is decisive). If not:

a. an accessible sludge container or 25 cm drain tank must be built into the fuel system³ ,
b. the fuel tank drain must be built in such a way that, in the normal position on the ground, water flows from all parts of the tank to the sludge tank or drain tank, and
c. the sludge outlet must be easily accessible and able to be easily put into operation.

2. Each fuel system outlet must be equipped with a device that can be safely manually or automatically locked in the closed position.

UL2-VI § 973 Fuel tank filler necks

The filler necks of the fuel tanks must be outside the area intended for persons. Poured fuel must not flow into the space in which the fuel tank is located or into any other part of the aircraft, outside of its own tanks.

UL2-VI § 975 Fuel tank venting

Each fuel tank must be vented at its top. Besides, they have to

1. each vent valve must be constructed and located in such a way that the risk of its clogging by ice or other foreign bodies is reduced to a minimum,

2. each vent must be designed to prevent suction of fuel due to negative pressure during normal operation,

3. every venting must be brought out into the free space.

UL2-VI § 977 Fuel strainer and filter

1. A fuel cleaner (fuel filter) must be placed between the fuel outlet from the tank and the carburetor inlet (or engine driven fuel pump if installed).

2. At the outlet of each fuel tank there must be a cylindrical strainer with three to six meshes per centimeter (suction basket). The diameter of the strainer must be at least equal to the diameter of the outlet from the fuel tank and the length of the strainer at least twice the diameter of the outlet from the fuel tank.

3. Each strainer or each filter must be easily accessible for inspection and cleaning.

UL2-VI § 993 Fuel lines and connections

1. Each fuel line must be installed and fixed in such a way as to prevent its excessive vibration and to withstand the loads created by the hydrostatic pressure of the fuel and from flight multiples.

2. Each fuel pipe that is fixed on such parts of the aircraft, the position of which can change with each other, must be equipped with a flexible member.

3. Flexible hoses must be proven to be usable for the intended purpose.

4. Leakage of fuel from any pipe or joint shall not directly impact hot surfaces or equipment so as to cause fire, or directly impact persons on board.

UL2-VI § 995 Fuel cocks and their control

1. A device must be installed that would allow the pilot to quickly shut off the fuel supply to the engine in flight.

2. The pipe section between the fuel "STOP" cock and the carburetor must be as short as possible.

3. Each fuel "STOP" - cock must have either solid stops or effective locking in the "OPEN" and "CLOSED" positions.

III. Oil system

UL2-VI § 1011 In general

1. If the engine is equipped with an oil system, this system must supply the engine with a sufficient amount of oil at a temperature that does not exceed the maximum value for safe continuous operation.

2. Each oil system must have a usable volume that is sufficient to supply for the maximum flight time.

UL2-VI § 1013 Oil tanks

1. Oil tanks must be built in such a way that

a. have met the requirements according to Chapter E, point UL2-VI § 967 paragraphs 1, 2, and 4. A
b. withstand all vibrations, inertial forces and hydrostatic loads that may occur in operation.

2. It must be possible to check the oil level without removing the cover parts (outside the filler cap) and without using tools.

3. If the oil tank is built into the engine compartment, it must be made of heat-resistant material.

UL2-VI § 1015 Tests of oil tanks

Oil tanks must be tested in accordance with Subpart E, Clause UL2-VI § 965, and a pressure of 0,035 MPa must be used for pressure tests.

UL2-VI § 1017 Oil pipes and joints

1. Oil lines must comply with Subpart E, Section UL2-VI § 993, and each oil line and connection must be made of material capable of withstanding the maximum operating oil temperatures.

2. The vent pipe must be arranged so that

a. there could be no accumulation of condensed water, which could freeze, or oil, which could clog the pipes, and

b. discharge from the vent pipe when oil foaming could not cause a fire hazard or so that the oil leaking from the pipe could not contaminate the wind shield in front of the person(s) on board or in front of the pilot(s).

IV. Cooling

UL2-VI § 1041 In general

Powerplant cooling equipment must be capable of maintaining the temperature of all powerplant components and engine operating fluids within the limits established by the engine manufacturer for all expected operating conditions or required by the airplane manufacturer for those operating conditions.

V. Intake system

UL2-VI § 1091 Air supply system

The air supply system must safely ensure the supply of the required amount of air to the engine under all expected operating conditions. The ingress of foreign bodies (grass, dirt, etc.) must be effectively prevented, preferably with a filter (sieve).

VI. Exhaust system

UL2-VI § 1121 In general

1. The exhaust system must effectively ensure the safe removal of exhaust fumes without the risk of fire and without contamination of the space intended for people with carbon monoxide.

2. Any part of the exhaust system the surface of which is hot enough to ignite flammable liquids or vapors shall be so located and covered that leakage from any system through which flammable liquids or vapors pass cannot cause a fire by liquid contact or steam with any part of the exhaust pipes including their covers.

3. All parts of the exhaust system must be far enough away from neighboring flammable parts, or they must be separated by heat-resistant covers.

4. The exhausts must not be located in the dangerous vicinity of the outlets of the fuel and oil system.

5. All parts of the exhaust system must be ventilated so that an unreasonably high temperature does not occur anywhere.

UL2-VI § 1125 Exhaust pipes

1. The exhaust pipe must be made of refractory material and have provisions to prevent expansion damage after heating to operating temperature.

2. The exhaust and damping system must be mounted in such a way as to withstand all vibrations and inertial forces that arise during normal operation.

3. Parts of the exhaust system that are connected to parts that change their relative position must be flexibly connected.

VII. Engine control device and its accessories

UL2-VI § 1141 In general

That part of each control device of the propulsion unit which is located in the engine compartment and must remain in operation even in the event of fire must be at least of heat-resistant material.

UL2-VI § 1145 Ignition switch

1. Each ignition circuit must be equipped with a separate switch.

2. Each ignition current circuit must be switched on independently and its operation must not be conditioned by switching on any other switch.

3. Ignition switches must be arranged and designed to prevent their inadvertent use.

4. The ignition switch must not be used as a main switch for other circuits.

UL2-VI § 1149 Propeller speed

Propeller speeds and settings must be limited to values ​​that effectively ensure safe operation under normal operating conditions.

1. During takeoff and climb at the speed recommended for best climb, the propeller must limit the engine speed with the throttle fully open so that it does not exceed the maximum allowable speed.

2. During gliding flight at speed V_NE with the inlet closed or the engine stopped, the propeller must not reach such revolutions that would exceed 110% of the maximum permissible revolutions of the engine or propeller (the lower value is decisive).

UL2-VI § 1191 Fire wall

1. The engine must be separated from the rest of the glider by a fire wall, cover or equivalent means if the structural arrangement permits.

2. The fire wall or cover must be constructed in such a way that no dangerous amount of liquid, gas or flame can escape from the engine compartment to other parts of the glider.

3. The fire wall or cover must be heat-resistant and protected against corrosion.

UL2-VI § 1193 Engine covers and engine nacelles

The following applies to the engine cover:

1. Engine covers must be designed and secured to withstand the vibration, inertia and air forces that may be expected in service.

2. Enclosures must be equipped with such a device that the escaping substances from all parts of the enclosures can drain quickly and without residue in all normal configurations on the ground and in flight. Leaking substances must not be diverted to places where there could be a fire hazard.

3. All parts of engine covers exposed to high temperatures due to proximity to parts of the exhaust system or due to direct contact with exhaust gases must be made of heat-resistant material.

 

TITLE F - EQUIPMENT

I. In general

UL2-VI § 1301 Function and construction

1. Each item of gear must

a. be of a type and design that enables the expected function to be fulfilled,
b. be, if possible, provided with suitable inscriptions for identification, description of function and operational limitations or any suitable combination of these elements,
c. be built in such a way as to comply with the specified restrictions that apply to this equipment, a
d. to work flawlessly after installation.

UL2-VI § 1301 a. (explanatory notes)

a. Faultless function should not be impaired by frost, heavy rain or high humidity.
b. If a flight safety device is installed, it must be proven that its operation is not affected by the glider's electrical devices.

2. Instruments and other equipment must not adversely affect each other or endanger the safe operation of the glider.

UL2-VI § 1303 Flight and navigation instruments

The following flight instruments must be installed in all gliders:

a. speedometer
b. altimeter
c. compass

UL2-VI § 1307 Other equipment

Each crew member must wear seat belts.

II. Installation of devices

UL2-VI § 1321 Arrangement and visibility

Flight and navigation instruments must be placed clearly and must be easy to read for each pilot.

UL2-VI § 1321 (Acceptable means of identification)

In order to meet this requirement, two-seat gliders with two controls may require a double instrument installation.

UL2-VI § 1323 Speedometer system

1. The speedometer system must be calibrated so that the speedometer indicates the correct airspeed under MSA conditions, H = 0 ms with a total system error of no greater than ± 6 km/h or ± 5%, whichever is greater. This requirement must be met in the speed range of 1,2 Vs1 to V_NE with flaps in neutral and aerodynamic brakes engaged.

2. The calibration curve of the speed measuring system (IAS – CAS speeds) must be constructed based on the results of flight tests.

3. The speedometer system must be capable of indicating the speed V_so at least up to 1,05 V_NE.

UL2-VI § 1325 Static pressure system

1. Each device containing a pressure box with a static pressure connection must be vented so that changes in glider speed, opening and closing windows, humidity or the influence of other foreign substances do not significantly affect the accuracy of the data.

2. Static pressure systems must be designed and constructed so that

a. the safe drainage of condensed moisture was enabled,
b. Pipe penetration was prevented and excessive deformation or narrowing in bends did not occur, and
c. the materials used were durable, usable for the intended purpose and protected against corrosion.

III. Electrical systems and equipment

UL2-VI § 1353 Design and installation of storage batteries

1. Accumulator batteries must be designed and built in accordance with the provisions of this point.

2. Explosive or poisonous gases escaping from the accumulator battery during normal operation or as a result of any possible malfunction of the charging device or the battery system must not accumulate in the glider in dangerous quantities.

3. Corrosive liquids or vapors that may escape from the battery must not cause damage to the surrounding supporting structure or adjacent important parts of the equipment.

UL2-VI § 1365 Electrical lines and accessories

1. Each electrical line must have a sufficient cross-section, must be appropriately routed, attached and connected in such a way that the occurrence of short-circuits and the associated fire hazard are with a high probability excluded.

2. Every electrical device must have overload protection. No safety device may be intended for more than one electrical circuit important to flight safety.

IV. Another gear

UL2-VI § 1431 Radio and radio navigation devices

Each used radio and radio navigation equipment device must meet the following conditions:

1. The equipment and its antennas must not create sources of danger neither by themselves, nor by the way in which they are used, nor by their influence on the operational characteristics of the glider.

2. The equipment and its control and indicating elements must be arranged in such a way that they are easy to operate. The construction must be done in such a way that overheating is prevented by sufficient ventilation.

UL2-VI § 1441 Oxygen devices and oxygen supply

1. The oxygen apparatus must be of an approved type.

2. The oxygen device and its construction must exclude hazards during its use and must not adversely affect other parts of the construction part.

3. Devices must be used to enable the crew to immediately ascertain in flight the usable oxygen supply in each oxygen cylinder.

4. Oxygen cylinders must be secured so that they do not create a source of danger during an emergency landing.

UL2-VI § 1449 Oxygen supply control equipment

Devices must be used to enable the crew to verify that oxygen is being supplied to the breathing units.

 

TITLE G - OPERATING LIMITATIONS AND DATA

UL2-VI § 1501 In general

1. The operational limitations specified in UL2-VI § 1505 to UL2-VI § 1523 and other limitations and data that are necessary for safe operation must be established.

2. Operational restrictions and other data that are necessary for safe operation must be accessible to the pilot as stipulated in UL2-VI § 1541 to UL2-VI § 1585.

UL2-VI § 1505 Flight speed

1. All airspeeds must be determined as indicated by the speedometer (IAS).

UL2-VI § 1505 (1) (explanatory notes)

Speeds (EAS) that result from strength constraints must be recalculated accordingly.

2. Maximum speed V_NE must not exceed 90% of the maximum speed demonstrated by flight tests (VDF).

3. Maximum speed V_DF must not exceed the maximum design speed V_D and must not be less than 90% of the design maximum speed determined according to UL2-VI § 335.

UL2-VI § 1507 Turnover speeds

The rotation speed must not exceed the design rotation speed V_A determined according to UL2-VI § 335.

UL2-VI § 1511 Speeds of use of flaps

At any setting of the positive deflection of the flaps (see UL2-VI § 335), the maximum permissible speed for the operation of the flaps must not be V_FE greater than 95% of V speed_F according to UL2-VI § 335, on which the supporting structure is dimensioned.

UL2-VI § 1513 Speeds for extending and retracting the drive unit

A range of power unit extension and retract flight speeds must be established along with any associated power unit extended flight speed limitations.

UL2-VI § 1515 Speed ​​for use of chassis

Maximum permissible speed for handling V chassis_LO, must be determined for the retractable landing gear if it is lower than the maximum speed V_NE. However, its value must not be lower than V_T or V_W– depending on which speed is greater.

UL2-VI § 1518 Speed ​​for air towing, winch start and start behind a motor vehicle

1. The maximum permissible speed in the aerofoil must not exceed the designed speed V_T, which is determined according to UL2-VI § 335, and must not exceed the speed demonstrated during flight tests.

2. The maximum permissible speed during a winch start or a start behind a motor vehicle must not exceed the designed speed V_W determined according to UL2-VI § 335 and must not exceed the speed demonstrated during flight tests.

UL2-VI § 1519 Weight and position of the center of gravity

1. The maximum weight defined according to UL2-VI § 25 1. must be established as an operational limitation.

2. The limitation of the position of the center of gravity defined in paragraph UL2-VI § 23 must be established as an operational limitation.

3. The weight of the equipped glider and the corresponding position of the center of gravity must be defined in accordance with UL2-VI § 29.

UL2-VI § 1529 Maintenance Manual

A maintenance manual must be created that contains information that the applicant considers important for proper operation and maintenance. The applicant must include at least the following important information in the handbook:

1. system descriptions,

2. lubrication plan, which must contain intervals between lubrication, specification of lubricants and lubricating fluids applicable to individual systems,

3. pressures and electrical loads, permissible for individual systems,

4. tolerances and adjustment values ​​that are necessary for the correct functioning of the glider,

5. methods and preparations for blocking, lifting and dragging on the ground,

6. the method of balancing the control surfaces and the maximum permissible value of the clearances in the hinges and the dead run in the control circuits,

7. permitted values ​​of pretension in the cables of control systems, determined in accordance with UL2-VI § 411 2.,

8. distinction between supporting and secondary (auxiliary) structures,

9. times between inspections and the scope of inspections necessary for proper maintenance of the glider,

10. special glider maintenance/repair procedures,

11. special inspection and test procedures, including a list of special tools,

12. data for weighing and determining the position of the center of gravity, which are necessary for the undisturbed operation of the glider,

13. determining the time of operation and the time limitation of the service life (replacement or maintenance) of parts of the glider, accessories and additional devices that are subject to these limitations,

14. a list of documents for the maintenance of parts, accessory parts and additional accessories that are approved independently of the glider,

15. materials needed for small repairs,

16. recommended methods of cleaning and technical maintenance,

17. assembly and disassembly instructions,

18. determination of support points and conditions for land transport,

19. list of labels and markings and their location.

I. Markings and labels

UL2-VI § 1541 In general

1. The glider must be equipped with:

a. marking and labels according to UL2-VI § 1545 to UL2-VI § 1557,
b. other additional data, labeling of devices and labels that are necessary for safe operation if they have an unusual design solution, unusual operational indicators or operational characteristics.

2. All markings and labels mentioned in paragraph 1.:

a. must be placed in a conspicuous place, a
b. must not be easily removable, changeable or difficult to read.

3. The same units as the speedometer must be used on the data and speed plates.

UL2-VI § 1543 Marking on devices

The following applies to all devices:

1. If the marks are placed on the glass cover of the device, it must be ensured that it is not possible to turn the glass cover in relation to the dial.

2. The arcs and lines must be wide enough and positioned so that the pilot can clearly see them without obscuring any part of the dial.

UL2-VI § 1545 Speedometer

The speedometer must have the following color markings:

1. Radial red line for speed V_NE .

2. Yellow arch in the upper part of the dial (area of ​​increased attention) by V_NE to the rotation speed V_A .

3. Green arc in the region of normal operating range, the lower limit of which is the rate of 1,1V_S1 at maximum weight (flaps in neutral position, see UL2-VI § 335) with retracted landing gear, and whose upper limit is the speed in strong turbulence V_RA.

4. White arc for the flaps extended speed range, the lower limit of which is a stall speed of 1,1 V_S0 for the maximum weight and whose upper limit is the maximum permissible speed V_FE for positive flap deflection.

UL2-VI § 1555 Designation of control and control elements

1. Every steering and control element in the cockpit, with the exception of the main controls, must be clearly marked and its function and method of use indicated.

a. The handle of the release mechanism of the parachute rescue system must be marked especially clearly and easily and must be arranged in such a way that the probability of inadvertent use is reduced to the smallest possible extent.

UL2-VI § 1555 1. (explanatory notes)

Instead of a verbal description, the marking of the control should preferably be marked with easily understandable and commonly used symbols.

2. The color marking of controls and control elements must agree with the colors specified in UL2-VI § 780.

UL2-VI § 1557 Miscellaneous markings and labels

1. Luggage Compartment: Each luggage compartment must have a label indicating the load weight limit.

2. For gliders with undercarriage wheel or undercarriage wheels, the tire pressure must be indicated.

3. If a removable weight is used, the weight installation location must be labeled with instructions for proper placement of the removable weight for all configurations for which the removable weight is required.

4. Maximum take-off weight of the glider.

5. Maximum and minimum crew weight.

6. Maximum permissible nominal strength of the securing member for the towing rope.

UL2-VI § 1559 Notice of operating restrictions

All gliders must have a placard in the pilot's field of vision with the following speed limit information (if not shown on the speedometer):

1. maximum permissible speed for winch start and start behind a Vw motor vehicle (if winch start and start behind a motor vehicle is allowed),

2. maximum permissible speed for aerofoil V_T (if air towing is allowed),

3. maximum turning speed V_A ,

4. the maximum allowable speed for extending the landing gear V_LO, if the chassis is available.

II. Flight manual

UL2-VI § 1581 In general

1. A Flight Manual must be prepared and submitted for each glider. Each flight manual must contain at least the information specified in UL2-VI § 1583 to UL2-VI § 1585.

2. Separation of data: All parts of the glider flight manual that contain the data specified in UL2-VI § 1583 to UL2-VI § 1585 must be separated from all other parts of the glider flight manual and must not be easily removable or falsifiable.

3. Additional data: All data not listed in UL2-VI § 1583 to UL2-VI § 1585, but necessary due to unusual construction, unusual operational indicators or operational characteristics, must be available.

4. Units: Speed ​​data on the dial and in the flight manual must always be in the same units.

UL2-VI § 1581 (explanatory note)

Note: Flight and maintenance manuals may be combined if a clear separation/distinction is made in the Content.

UL2-VI § 1583 Operating restrictions

1. Flight speed limitations: The limitations must include:

a. The data required to indicate the flight speed limit on the speedometer according to UL2-VI § 1545, and at the same time an explanation of the meaning of these individual limit values ​​and the meaning of the color markings.
b. Velocity data V_RA, VA, V_LO, V_T, V_W, and their meaning if applicable.

2. Weights. The following information must be provided:

a. maximum take-off weight,
b. the weight of the equipped glider including the weight of the rescue system and the relevant position of the center of gravity, while the weight of the rescue system must be part of the weighed weight of the equipped glider,
c. load distribution, ie crew and (if permitted) cargo.

3. Load. The required data must include:

a. restrictions on weight and extreme positions of the center of gravity according to UL2-VI § 23 and UL2-VI § 25, including those parts of the glider that are included in the weight of the equipped glider according to UL2-VI § 29,
b. data enabling the pilot to determine whether the position of the center of gravity and the distribution of the load under different combinations of loads still remain within the specified permissible range,
c. data on the correct deployment of removable ballast for each flight configuration for which the use of removable ballast is required.

4. Multiples. The following positive operating turnover multiples are established:

a. for V_A the multiple that corresponds to points A and G in Figure 1 according to UL2-VI § 333 2,
b. for V_NE multiple that corresponds to points D and E in Figure 1 according to UL2-VI 333 2.

5. Rubber rope start: The following information must be provided:

maximum permissible tensile force at 100% stretching (elastic elongation).

6. Air tow, start with winch or motor vehicle. The following information must be provided for an air tow, winch launch or motor vehicle:

a. the maximum permissible nominal strength of the towing rope or the strength of the fuse,
b. the minimum length of the towing rope determined according to UL2-VI § 151 4.
c. the value of the maximum force in the rope when starting with a winch or behind a motor vehicle.

7. Start with your feet (by your own power). If the glider is capable of launch by the pilot's own forces, all necessary data for a safe launch must be provided.

UL2-VI § 1585 Operating data and procedures

Information on normal and emergency procedures must be given, as well as any other information necessary for safe operation, including the following:

1. Falling speed in different configurations.

2. Any loss of height greater than 30 m or exceeding the longitudinal slope by more than 30⁰ below the horizon, which occurs during the resumption of normal level flight after putting the glider into a maneuver according to UL2-VI § 201.

3. Any height loss greater than 30 m that occurs during the resumption of normal level flight after the glider has been maneuvered according to UL2-VI § 2031.

4. How to prevent accidental corkscrewing. In the case of a glider that is not demonstrably resistant to accidental corkscrewing, the procedure for removing the corkscrew must be indicated.

5. Display of labels and their text.

6. Gliding properties in configuration with aerodynamic brakes extended.

UL2-VI § 1587 Performance data

The following information must be established:

1. instrument error of the speedometer device, a

2. proven crosswind speed limit.

 

APPENDIX I - RESCUE SYSTEMS

I. In general

1. For the installation of a certified rescue system (ZS), it is necessary to demonstrate that it fully meets the requirements of the regulation for rescue systems for ultralight aircraft as currently amended.

2. The installation of a rescue system in a UL aircraft by its manufacturer or owner must be approved by the manufacturer of the type-certified ZS.

3. The structure and its attachment points must be documented in the Operations Manual.

II. Rescue system load

1. The structure between the attachment points of the rescue system's support ropes must be designed to withstand the dynamic impact that occurs when the rescue system is put into operation and corresponds to the values ​​specified by the manufacturer. Furthermore, it is required that the design and fastening of the seats, safety belts and subsequent structures up to the anchorage points of the vehicle must withstand the forces caused by the weight of the crew as a result of the dynamic shock from the vehicle.

2. Dynamic shock multiplied by a factor of 1,5 = safe load.

3. If the load-bearing ropes are fixed at several points of the load-bearing structure, then each individual fixing point must bear the load, which is defined as follows:

a. Main curtains are always front hinges, which must be dimensioned as follows:

i. One main hinge – must be sized for a safe load.
ii. More main ones of hangers (usually 2) - each hanger must be sized for the following load: (safe load divided by the number of main hangers) multiplied by a factor of 1,33.

b. Zadni hinges (stabilizing).

i. The strength of each hinge – each individual fastening point must be dimensioned as follows: (safe load divided by the number of all fastening points, including the main ones) multiplied by a coefficient of 1,33.

Example of calculating the load from the rescue system:

Input data: flight weight 450 kg, speed V_D = 300 km/h, dynamic impact from ZS is 5 g, the aircraft has 4 hinges (2 front main and 2 rear stabilizers), basic safety factor = 1,5, additional safety factor = 1,33.

Safe load:

Stabilizer hinge load:

4. When designing the ZS attachment points, it must be considered that the dynamic impact acts on the strength structure in all the following directions:

a. in a vertical plane from a direction parallel to the longitudinal axis of the aircraft backwards to a direction of 60° upwards and
b. in the range of 30° to both sides from the axis of symmetry.

III. Building a rescue system

1. The attachment of the rescue system must be designed for a maximum multiple that corresponds to the specified flight and landing load cases, including the prescribed load during an emergency landing.

2. If the rescue system is located in front of the propeller, such a device must be installed to prevent interruption of the propeller support cables.

3. In the event of putting the rescue system into operation, the fastening and the surrounding strength structure must be able to absorb a possible recoil.

Warning: the amount of recoil can be thought of as a numerical value.

4. The device that activates the rescue system must be located so that it is easily accessible by the pilot and easy to use even under overload conditions.

5. The structure between the attachment points of the support cables and the seat, including the safety belts, must be able to absorb the shock when the rescue system is deployed according to Chapter B.

6. The rescue system must adjust the angle of the cabin so that the risk of injury to the pilot is low in the event of an impact. At the same time, the possible influence of the wind or the loss of parts of the glider must also be taken into account. If the operation of other aids is not expected (such as an airbag or fixed chassis), the longitudinal inclination of the cabin during the impact must be between 20° and -40°.