Download the valid version in the Czech language (link to the PDF version of the regulation)
Note: The content of the prescription is identical to the PDF document only in the Czech version. In foreign language versions, this is an automatic translation that is not legally binding.
ZL 2 – part I.
Content
TITLE 1 – Introductory provisions
TITLE 2 - Definitions
TITLE 3 – Technical requirements for airworthiness of ZK
TITLE 4 – Operational characteristics of the hang glider
TITLE 5 - Operating restrictions
TITLE 6 - Operating instructions
TITLE 7 - Amendments
TITLE 8 – Annex 1 ZL2/I
TITLE 9 – Annex 2 ZL2/I
TITLE 1 – Introductory provisions
1.1 these building standards contain the minimum requirements that must be met to obtain a hang glider Technical Airworthiness Certificate.
1.2 The procedure for verifying the airworthiness of hang gliders is determined by LA 2 procedures.
TITLE 2 - Definitions
2.1 A hang glider (HG) is an engineless heavier air aircraft that is designed for a maximum of two people and whose take-off is carried out by the pilot's take-off, aerofoil or winch, which is controlled by changing the position of the pilot's center of gravity, with the possibility of additional aerodynamic control around one axis. The maximum weight of an empty glider without a clamping device must not exceed 40 kg.
2.2 Aerodynamic control is control of the ZK in flight by means of deflection of control surfaces controlled by the pilot
2.3 The support structure ZK is a system of approach beams including end beams and struts, reinforcing ropes, keel beams, crossbars, transom and mast, including their structural nodes, the system of ropes and their anchoring and those parts of the structure, the failure of which would seriously endanger the safety of the ZK
2.4 A flexible cover is a cover of the bearing surface that does not maintain its flight shape at rest.
2.5 A fixed cover is a cover of the airfoil that maintains its flight shape at rest.
2.6 The ZK rope system is a system of ropes anchored in structural nodes that strengthen and stiffen the supporting structure.
2.7 The pilot's suspension is a device of the supporting structure used to suspend the carabiner of the ZK pilot's suspension harness
2.8 A suspension harness is a pilot's harness in which the pilot is suspended during flight at the ZK
2.9 The minimum weight of the ZK is the smallest weight at which the ZK complies with the standards for airworthiness
2.10 The maximum weight of the ZK is the largest weight at which the ZK complies with the standards for airworthiness
2.11 The maximum weight of a pilot is the largest permitted weight of pilots with full equipment
2.12 The minimum weight of the pilot is the smallest permissible weight of the pilot with full equipment
2.13 The weight of an empty hang glider is the weight of the ZK with a fixed weight and specified equipment without the weight of the pilot, rescue system, suspension harness, transport packaging, instruments and the weight of other, easily removable parts of the cargo.
2.14 Operating load is the largest load expected in operation
2.15 The operating load factor (n) is the ratio of the operating load to the ZK flight weight.
2.16 Bearing surface (S) is the area of the bearing surface projected onto a plane parallel to the chords airfoil and with the direction of flight.
2.17 Span (I) is the largest dimension of the bearing surface measured perpendicular to the direction of flight
2.18 Leanness (lambda)
lambda = l2/S
2.19 Surface load (q) where m is the mass of the ZK and g is the gravitational acceleration
q = mg/S(N/m)
2.20 Abbreviations
ZK – hang glider
TPLZ – technical certificate of airworthiness
TITLE 3 – Technical requirements for airworthiness of ZK
3.1 Design and construction
3.23.1 General
3.23.1.1 The strength of any part of the ZK, which has a significant effect on safety and which cannot be verified by proof calculation, must be proven by a test
3.23.2 Materials
3.23.2.1 The suitability and durability of all materials used must be proven primarily by a quality certificate or tests. All materials used for stressed parts must conform to approved standards and specifications
3.23.2.2 The production processes used must guarantee faultless constructions that are reliable in terms of preserving the original strength under the expected operating conditions.
3.23.3 Protection of parts
3.23.3.1 Each part of the supporting system must be sufficiently protected against harmful effects such as weather, corrosion, wear and tear during operation and transport.
3.23.4 Connection insurance
3.23.4.1 Approved means must be used to insure connections. Self-locking nuts on screws that can rotate during operation must not be used.
3.23.4.2 Assembly and disassembly
3.23.4.3 The structure must have such properties that no damage or permanent deformation occurs during assembly or disassembly. Incorrect installation of the ZK must be easy to check.
3.23.5 Adjustability
3.23.5.1 Any modifiability affecting flight performance must be detailed in the flight manual. The device allowing adjustment in flight must be arranged in such a way that the forces generated when handling it are manageable by the pilot and that they do not allow for spontaneous adjustment.
3.23.6 Strength properties of the material
3.23.6.1 Static strength properties
3.23.6.1.0.1 The strength properties of the materials used must be documented by a material certificate or a report on the result of the strength test so that their values can be used in the static calculation.
3.23.5.1.0.2 Where the temperature reached in a significant part of the structure under operating conditions could have a significant negative effect on the strength of the structure, the calculation must take this fact into account.
3.23.6.2 Fatigue strength
3.23.6.2.0.1 During the design of the structure, structural nodes with a dangerous stress concentration must be excluded, also with regard to the effects of vibrations.
3.2 Increasing safety factors
3.24.1 In general, the safety factor for ZK is 1,5
3.24.2 The safety factor of 1,5 must be multiplied by a special factor if:
3.24.2.0.0.1 there is doubt about the real strength of any part of the supporting system or
3.24.2.0.0.2 a reduction in in-service strength must be expected prior to normal replacement, or
3.24.2.0.0.3 the strength of the parts shows a variance that is caused by uncertainties in manufacturing and inspection methods
The size of this special coefficient must be chosen so that the failure of any part due to low strength for the reasons mentioned is unlikely.
3.24.3 Values of the increasing safety factor:
Forging – 2
Components subjected to severe stress - 2
Sail – 5
Connecting nodes – 2
Castings – 2
Pilot hinge – 2
Wool – 2
3.24.4 Building units
3.24.4.1 Assembly - the possibility of incorrect assembly must be made as difficult as possible by the structural design of the individual building parts or by clear and permanent marking
3.24.4.2 The frame must be arranged in such a way that it is practically impossible to damage the supporting parts during assembly and disassembly or during flight. The tubular framework must be reinforced in all places where the supporting tubes are weakened by holes. The minimum length of reinforcement of the pipe joint with a reinforcing insert is equal to three times the diameter of the pipe. It must be ensured that the pipes cannot be deformed to an unacceptable extent due to the tightening of the screws.
3.24.4.3 Plachta
3.24.4.3.1 Fabrics or other materials and semi-finished products used for the manufacture of sails must not be significantly exposed to the harmful effects of the environment with regard to the rapid deterioration of mechanical properties. It must demonstrate sufficient bending strength and sufficient resistance to ultraviolet radiation. Materials must be used so that fluctuations in temperature and humidity do not adversely affect flight characteristics.
3.24.4.3.2 Processing – the tarpaulin must be professionally processed. All seams that are stressed in flight must be sewn with a double zigzag stitch. Straight stitches must not be used in stressed areas.
3.24.4.3.3 The attachment of the tarpaulin must be done in such a way that the tarpaulin does not tear off from the supporting structure or the ropes at the required largest numerical multiple of ZK.
3.24.4.3.4 The stitching of the stitches in the load-bearing areas must be done by double sewing a zigzag stitch with a minimum length of 20 mm.
3.24.4.3.5 The pockets of the cover reinforcements must be made in such a way that damage to the load-bearing seams of the tarpaulin is practically excluded when the reinforcements are inserted.
3.24.4.3.6 Reinforcement of the part of the tarpaulin that is subjected to excessive stress during assembly or transport must be done in such a way as to avoid damage. Straps and loops must also be reinforced.
3.24.5 Rope system ZK
3.24.5.1 Steel ropes
3.24.5.1.1 The steel ropes used must consist of at least 49. wires
3.24.5.1.2 The ropes must be provided with protection against corrosion
3.24.5.1.3 The structure must not cause breaks in the ropes
3.24.5.1.4 Ropes must not be broken during assembly and disassembly and must not be guided over unprotected sharp edges.
3.24.5.2 Crimping or entangling the rope
3.24.5.2.1 The ropes must be crimped or braided according to the relevant standard
3.24.5.2.2 Each wire rope must have a separate ferrule at each end
3.24.5.2.3 The termination of the rope is carried out according to the technical standard TN-04
3.24.5.3 Eye sockets
3.24.5.3.1 The material and dimensions of the eyelets must correspond to the rope used
3.24.5.4 Rope tensioner
3.24.5.4.1 Tensioners must be secured against adjustment
3.24.5.4.2 The fastening of the turnbuckles must be arranged in such a way that the bending of the stems is excluded.
3.24.5.4.3 No tensioner may be placed on the bottom rope of the ZK
3.24.5.4.4 The disconnection of the ropes must not be changed arbitrarily
3.24.5.5 Pins
3.24.5.5.1 The studs must not be stressed in the threaded part by shearing or bending. Deviations must be proven by a fatigue test.
3.24.5.6 Fittings
3.24.5.6.1 Fittings must be sized to withstand the applied load without permanent deformations and fulfill all functions. It must not have any sharp edges or ribs that could damage other parts of the ZK.
3.24.5.6.2 Fittings whose function can be affected by temperature must perform their function safely in the temperature range from +70°C to -15°C.
3.24.5.6.3 Fittings must be protected against corrosion. Possible contact of different materials must not be the cause of electrochemical corrosion
3.24.5.7 Pilot's compartment
3.24.5.7.1 The pilot's compartment must be designed in such a way as to eliminate as much as possible the risk of injury to the pilot by projecting parts, for example during an emergency landing
3.24.5.8 Suspension harness
3.24.5.8.1 The ZK suspension harness must comply with technical standards TN-05 and TN-04
3.3 Strength
3.25.1 Load
3.25.1.1 The strength requirements are determined by data on the operational load (the highest load that can be considered during operation) and the intermediate strength load (the operational load multiplied by the safety factor). Unless otherwise stated, operating loads are always given.
3.25.2 Factor of safety
3.25.2.1 The value of the safety factor is set at 1,5
3.25.3 Strength and deformation
3.25.3.1 The supporting system must be able to transfer the operating load without causing permanent deformations. Under all loads up to operational loads, the resulting deformations must not endanger the safe operation of the ZK. In the static strength test, the supporting system must be able to transfer the load to the intermediate strengths for a period of at least three seconds without the structure breaking. However, the three-second limit does not apply if the strength is demonstrated by dynamic tests in which real stress conditions such as in flight are simulated.
3.25.4 Fortification certificate
3.25.4.1 A dynamic load test on a test car is required if the strength requirements cannot be reliably demonstrated by calculation
3.25.5 Load Multiplier
3.25.5.1 The required load multiples are the total load multiples. When calculating the load under the prescribed extreme conditions, it must be assumed that the relevant multiple is caused by a sudden change in the angle of attack at a constant speed.
3.25.6 Required load multiples (n)
| Load sense | Operating | Between the fortresses |
| positive | n = 4 | n = 6 |
| negative | n=-2 | n=-3 |
The required load multiples are related to the maximum permissible flight weight. A license plate can be recognized for a negative load of ZK.
TITLE 4 – Operational characteristics of the hang glider
4.1 Proof of flight characteristics
4.26.1 Proof of the flight characteristics of the ZK must be provided by appropriate flight or other tests.
4.26.2 Unless otherwise stated, compliance with all individual requirements of this chapter must be demonstrated for all limit values of weight and position of center of gravity and for all limit values of pilot weight, center of gravity position and limit values of ZK adjustment proposed by the manufacturer
4.2 Instrumentation for flight tests
4.27.1 For flight tests, the ZK must be equipped with devices that allow it to be carried out in a simple way necessary measurements and observations.
4.3 Load distribution limits
4.28.1 The range of weights and suspensions in which the ZK can be safely operated must be established.
4.4 Maximum weight
4.29.1 The maximum weight must not be greater than:
4.29.1.0.1 the highest weight proposed by the applicant
4.29.1.0.2 the highest computing weight, or
4.29.1.0.3 the highest weight with which the operational properties are demonstrated
4.5 The lowest weight of ZK
4.30.0.0.1 The load per unit area of the ZK wing must not be less than 50 N/m
4.6 The weight of an empty hang glider must not exceed 40 kg
4.7 Weight of the pilot
4.32.1 The weight of the pilot means the weight of the pilot together with the suspension harness, rescue system and other gear
4.8 Burden
4.33.1 Fixed weight adjusting the position of the center of gravity
4.33.2 A load that is dependent on the weight of the pilot in order to achieve the minimum permissible weight of the pilot
4.9 Slipperiness
4.34.1 The lowest ZK glide must be at least 4
4.10 Speeds
4.35.1 Falling speed (Vs)
4.35.1 Stall speed is the lowest steady speed at which the ZK is still controllable if:
4.35.1.1.1 the pilot is suspended approximately upright,
4.35.1.1.2 flight weight corresponds to the highest landing weight,
4.35.1.1.3 the center of gravity and the point of suspension are in such a position that it is possible to achieve a falling speed
4.35.2 Top speed ZK
4.35.2.1 The highest permissible speed of ZK must be at least 55 km/h. In doing so, the pilot must not exceed the permissible forward position of the center of gravity and must hold the bar in his hands.
4.11 Ground tests
4.36.1 All ground functions must be tested prior to commencement of ground tests. Especially it is it is necessary to record the weight of the ZK and check the suspension harness.
4.12 Take-off characteristics
4.37.1 The ZK must be controllable during take-off and must not exhibit any exceptional flight conditions. With ZK it must be possible to take off without external assistance, without requiring exceptional effort or dexterity on the part of the pilot.
4.12 Approach and Landing
4.38.1 Control of landing gear in flight at all permissible speeds must not cause excessive changing the necessary control forces or control deviations, nor affect the controllability of the ZK in such a way that it would require extremely special interventions by the pilot.
4.38.2 There shall be no excessive yaw, overturn or pitching moments during landing.
4.14 In-Flight Properties
4.39.1 It must be possible to fly the ZK in the full range of speeds and in all modes and perform all normal flight positions, without requiring excessive effort and dexterity of the pilot.
4.39.2 It must be possible to change the flight mode smoothly under all likely operating conditions without it would require exceeding the operating load multiples.
4.39.3 Unusual operating characteristics observed during the tests shall be recorded to the test report.
4.15 In-Flight Properties
4.40.1.1 Speed control
4.40.1.1. It must be proven that the ZK complies with the following requirements:
4.40.1.1.1 acceleration from 1,1 Vs to 1,5 Vs in a maximum of 5 s
4.40.1.1.2 ZK must be able to maintain approximately horizontal flight without special maneuverability. This must be possible even with the landing gear retracted or extended
4.40.1.2 Lateral and directional control
4.40.1.2.1 By appropriately repositioning the pilot's center of gravity, it must be possible to go from a 30 degree bank turn in one direction to a 30 degree bank turn in the opposite direction in 5 s. This turn must be possible without requiring special piloting skill.
4.16 Balanceability
4.41.1 ZK must be able to balance to a speed between lowest descent and best glide
4.41.2 ZK must continue to fly at the same speed with the trapeze freely held, without changing the direction of flight and must tendency to corner or sideslip
4.17 Stability
4.42.1 ZK must show sufficient stability under all normally occurring operating conditions
4.42.2 Static longitudinal stability
4.42.2.1 The steering force must increase with speed so that each major change in speed produces such a change in hand force that the pilot is clearly aware of it. The required control force must show an increase at each speed when the landing gear is retracted or extended and when the pilot is in the ready-to-land position.
4.42.2.2 The deflection of the bar must increase with increasing speed.
4.42.2.3 Retraction height - the ZK must be found to return to a steep flight position at zero initial speed with zero angle of attack to normal flight with a loss of height of up to 50 meters without sudden movement.
4.42.2.4 ZK behavior after a stable flight failure.
4.42.2.4.1 It must be proven that the ZK exhibits sufficient self-stable flight characteristics at all permitted flight speeds, that is, it will independently return to its original flight mode after a failure with the bar firmly held.
4.42.3 Directional and lateral stability
4.42.3.1 Straight flight – ZK must remain in straight flight without side slides for 10 seconds while holding the trapeze freely.
4.42.3.2 Flight in a turn - during a flight in a turn, the reversible steering force must not be so great as to make steering difficult.
4.42.4 Dynamic stability
4.42.4.1 Rapid oscillations that occur between the fall and the maximum permissible speed must be damped, both when the bar is loosely held and when it is firmly held.
4.18 Drag tests in direct flight
4.43.1 Putting into stalled flight condition - Stall tests in straight flight must be carried out in such a way that the speed is slowly reduced until a stalled flight condition is reached, which is manifested by an uncontrollable tilting from the front or over the wing.
4.43.2 Return to normal flight status – When returning to normal flight status from a stall, it must it should be possible to avoid a transverse tilt of more than 30 degrees by normal use of the steering. At the same time, the ZK must not show any unmanageable inclination to the corkscrew.
4.43.3 Fall – When the ZK in normal flight condition is indicated by a corresponding rapid movement of the controls from direct flight at high speed to a longitudinal slope of about 30 degrees above the horizon, the subsequent fall must not be sharp and the return to normal flight condition must not be difficult.
4.43.4 Corkscrew and steep spiral - There must be no tendency to corkscrew or steep spiral
4.19 Properties at high speeds
4.44.1 Each ZK must be designed in such a way that it is not possible to accidentally exceed the maximum permissible speed
4.20 Control of air brakes and landing aids
4.45.1 Built-in airbrakes or landing aids, if any, must be capable of being extended or retracted at each speed up to the maximum permissible speed without causing damage to the strength system or causing significant changes in flight attitude.
4.21 Flutter (flatr) and shaking
4.46.1 No part of the ZK may exhibit excessive oscillations throughout the permissible range of speeds. In addition, in normal flight, there must be no shaking that is so violent that it would lead to an unacceptable influence on the ZK control, excessive fatigue of the pilot or damage to the strength system. Shaking as a drag warning within these limits is allowed.
TITLE 5 - Operating restrictions
5.1 General
5.47.1 Operating limitations set out in this paragraph and other operating data that are necessary for safe ZK operation must be made available to the pilot and listed in the operating instructions - the ZK operating manual.
5.2 Determination of flight speed
5.48.1 All airspeeds must be given in values as read on the speedometer.
5.48.2 The speedometer system shall be arranged to show as far as possible the actual airspeed.
The data error does not exceed +- 8 km/h.
5.3 Flight and Operations Manual
5.49.1 Each individual ZK must be supplied with a flight and operations manual in which all operating data and limitations - see LA Procedures 2
TITLE 6 - Operating instructions
6.1 Each operating manual must contain at least the information listed in this chapter. If additional data are required for operational safety due to an unusual solution, mode of operation or operational characteristics, then they must also be provided.
6.2 Operating Limitations
6.51.1 Limiting flight speed
6.51.1.1 stall speed at the smallest and largest permitted weight of the pilot
6.51.1.2 maximum speed limit
6.51.2 Weights
6.51.2.1 Minimum pilot weight
6.51.2.2 Maximum pilot weight
6.51.2.3 The weight of the empty ZK and the position of the center of gravity at the weight of the empty ZK
6.51.3 Permissible range of pilot suspension point on ZK
6.51.4 Load multiplier when selecting a steep flight
6.51.5 Other requirements – If ZK imposes special requirements on pilots, they must be listed in the operating instructions (high performance gliders)
6.3 Operating Procedures
6.52.1 Operating procedures must contain data on normal and emergency procedures (take-off, flight, landing instructions) as well as data that is necessary for safe operation. In particular, a checklist of mandatory actions before take-off must be drawn up.
6.4 Assembly and transportation
6.53.1 The operating instructions must contain instructions for assembling and disassembling the ZK in the correct order and for its transport.
6.5 Maintenance
6.54.1 The instructions must contain the following data for the maintenance of the ZK:
6.54.1.1 Description of ZK
6.54.1.2 ZK adjustment data that will guarantee trouble-free operation
6.54.1.3 Service life and operating periods for replacement of parts
6.54.1.4 Procedure for determining the position of the center of gravity of the ZK
6.54.1.5 Schedule and scope of maintenance work and planned inspections
6.54.1.6 List of original parts and materials required for minor repairs
6.54.1.7 List of special tools if needed
6.54.1.8 Recommendations for daily maintenance
6.54.1.9 Instructions for storage
6.54.1.10 Operating times for individual parts and systems
TITLE 7 - Amendments
7.1. Classification of changes:
7.55.1 Those changes that do not affect the strength of the structure or the flight characteristics are insignificant
7.55.2 Those changes that affect the flight characteristics or the strength of the ZK structure are significant
7.2 All significant changes are subject to the obligation to notify or request them in advance consent of the LAA CR technical inspector with whom the ZK is registered and who will assess their influence on the airworthiness of the ZK.
TITLE 8 Annex 1 ZL2/I
Technical standard
for the strength control of suspension gliders controlled by changing the center of gravity with a flexible coating
1. Hang Glider - Small Slenderness - λ < 4
Tubing
Run-up beam
Transverse
Keel
Flying end of beam tube lflight must withstand a 0,22 G bendpil. The free end of the keel must not be longer than 1,5 of the length of the front part of the keel.
See Table I.
At the point of connection of the cross member to the tube of the leading beam, reinforce it externally or internally with a duralumin tube of min. length 8 d1 . Total wall thickness at the point of reinforcement min. 3 mm.
Trapeze
Use a pipe of the same diameter and wall thickness. A vertical (trapezoidal) pipe must withstand a buckling of 3,5 Gpil.
See Table II:
Suitable material quality is 424201.6, 424203.6.
Screws
Material of min. strength 800 MPa, tough. Class 15 steels are most suitable.
Minimum diameters:
For the connection of the transom - the riser. pipe M8
For connecting the transom - keel M8
For other connections M6
Screw connections must be secured:
Connections that can be disassembled and assembled when unfolding and folding the ZK with safety pins or cotter pins. Other connections with self-locking nuts.
Defectoscopy of screws
It is prescribed for the main connecting bolts of the approach beams and the central fittings.
Minimum ductility of screws according to 1.2.1. must be greater than 10%.
Card:
– burst test
– hardness test
– bending test – bending over the edge by 90° with a mean bending radius of max. 1,5 x diam. screw
One of the listed tests is sufficient.
Wool
Minimum load capacity of all ropes = 6.Gpil (table bearing capacity). In amateur constructions, a practical test of a rope with an end according to ČSN 313442 or 024481 is required with tension = 3.Gpil
Recommended ropes:
aerial rope diam. 2,5 mm ČSN 024321.65
aerial rope diam. 3,15 mm ČSN 024322.65, 024323.65 (ONL 3725)
When using ropes with a textile core, it is necessary to preserve the core with a suitable agent (grease, resistin, silicone oil) in order to prevent length changes due to moisture.
Pilot hinge
The pilot suspension is made of nylon or polyester rope (strap). It must be for two independent jobs. Min. rope strength 5 KN.
The connecting carabiner or eye must have a strength of min. 10 kn.
Plachta
A sewn tarpaulin of min. strength 10 kNm-1. In all places where the sail is connected to the frame and in places of stress concentration, the sail must be reinforced.
Fittings, center construction and connecting parts
It must correspond to the strength of the material used and the structural design to the strength of the pipes and ropes. The material used for these parts must be tough (alloyed steel and hardened duralumin). The design must not allow the screws to bend when folding the hang glider!
Hang glider – slenderness λ > 4 – transverse structure, reinforced lead tube
Tubing
Run-up beam
Transverse
The flying end of the approach beam and the cross member must withstand a buckling of 4,4 Gpil
See Table III
At the point of connection of the cross member to the tube of the leading beam, reinforce it outside or inside with a duralumin pipe by min. length 8 dl. Total wall thickness at the point of reinforcement min. 3 mm.
Trapeze: Like gliders of small slenderness
Screws: Like gliders of small slenderness
Wool: Like gliders of small slenderness
Pilot suspension: Like gliders of small slenderness
Plachta
A sewn tarpaulin of min. strength 15 kNm-1. In all places where the sail is connected to the frame and in places of stress concentration, the area must be reinforced.
Fittings and connecting parts: Like gliders of small slenderness
Outrigger
Strut lengths lv > 300 mm. The outrigger must support 50 N (5 kg) at the end in all directions.
Hang glider – slenderness λ > 4, leading beams unreinforced (without outriggers).
Run-up beam – must withstand the bending moment M without permanent deformationo = 0,28Gpil.
The condition for the flying end of the beam is:
The calculated values are shown in Table IV.
Connection of the leading beam with the crossbar.
Connection when the riser pipe is not drilled in the place of tensile stress: The reinforcement in the place of the connection (cover or insert) must meet the condition Wz = 1,5Wo , min length of reinforcement is 8 dl
Connection by means of screws (pipe drilled at the point of tensile stress): the reinforcement at the point of connection (sheath or insert) must meet the condition Wz = 2,25Wo.
Calculation: dp – the outer diameter of the reinforcement
dv – inner diameter of gain
The insert or cover must not cause a strength notch. It is recommended to thin the edge of the cover or cut it diagonally.
Defectoscopy of cracks must be carried out very carefully, especially in the vicinity of the junction of the riser - transom at +, - 1 m.
Test of the bending strength of the pipes for the approach beam - the pipe is supported at two points 1 /m/ apart and loaded in the middle with a load weighing mpil. There must be no permanent deformation. The calculated values are shown in Table V. ie bending. moment M = 0,25 mpil.gl
A hang glider of an unusual design.
The strength and technical requirements must be consulted with the LAA CR.
TABLE I.
Maximum length of the flying end of the nose tube for gliders of small slenderness λ < 4 (unreinforced nose spars)
TABLE II.
The maximum length of the trapeze arm in meters.
TABLE III.
The maximum length of the transom for more slender gliders – λ > 4
TABLE IV.
Maximum length of the flying end of the lead pipe, unbound, – λ > 4
TABLE V.
Distance of supports for proof of bending strength of pipes in meters.
Technical nroma for duralumin tubes for hang gliders.
Introductory provisions
Duralumin tubes made according to Czech or foreign standards can be used for the production of hang gliders, which must meet the strength and quality requirements to ensure the safe operation of ZK.
Pipe inspection and mechanical removal of pipe surface defects caused by contamination.
The customer shall inspect the pipes no later than 14 days after receiving the pipes from the supplier. After the pipes are de-preserved, the pipes are checked for cracks by color defectoscopy or another method. Special attention must be paid to the lead pipe at +- 1 m from the point of connection of the lead pipe with the cross member. The surface of pipes that have passed the inspection for cracks is then carefully visually inspected in order to detect surface defects and traces of mechanical damage. Detected defects can be removed by cleaning up to a depth equal to half of the permitted tolerance, while the lower limit tolerance of the pipe must not be exceeded. Pipes with deeper defects must be discarded or the defective area reinforced with an insert. After the inspection according to the previous point, it is possible to anodize the surface of the pipes.
Pipe storage
The tubes must be preserved and stored in dry and closed but well-ventilated rooms. Storage in the open is not allowed.
Surface treatment of pipes
Pipes and other parts of ZK must be protected against corrosion with suitable surface protection:
– by anodizing
– a suitable coating. In this case, it is necessary to carry out regular inspections
– It is necessary to provide anti-corrosion protection for the inner surfaces of the pipes as well
Technical standards for hang glider covers
Introductory provisions
This directive establishes uniform principles for the use of suitable materials for ZK covers.
Determination of types of materials suitable for ZK covers
a) Technical conditions for fabrics serving as covering material for ZK.
I. General appearance of the fabric
When laid on a flat surface, the fabric must not form any bulges, bulges or undulations in the direction of the weft and especially in the direction of the warp.
II. Straightness of the weft system
The straightness of the weft system is determined by the maximum bending or undulation of the weft system (see Fig. 1.)
Max. the permissible value is 1,5%. It is calculated from the relationship: U = X1/ H . 100 /%,cm,cm/
III. The directness of the curriculum
The straightness of the warp system is determined by the maximum bending or undulation of the system (see Fig. 2.)
Max. the permissible value is 0,5%. It is calculated from the relationship: O = X2/H.100 /%,cm,cm/
Minimum fabric strength
The strength of the fabric in the warp direction should be at least 220 N/cm.
The strength of the fabric in the weft direction should be at least 180 N/cm.
The strength of the fabric in the diagonal direction / 45° / should be at least 120 N/cm.
Maximum elasticity of the fabric at a tension of 23,5 N/cm
The elongation in the direction of the warp must be a maximum of 0,8%.
The stretch in the weft direction should be a maximum of 1%.
The elongation in the diagonal direction / 45° / should be a maximum of 10%.
The method of sewing covers and the use of suitable threads for polyester materials
The sewing method must comply with all principles of aerodynamic cleanliness and maximum cover strength. Places with stress concentration must be reinforced. Threads for sewing must always be made of polyester or polyamide.
All seams must be made with a basting stitch.
Service life of ZK covers
The durability is limited by the type of cover fabric, the period of use and the formation of permanent deformations that cause the covers to shake. It also depends on the degradation of strength due to UV radiation and operational wear.
In case of indecision, it is necessary to carry out a strength test of a sample cut from the coating.
Repairs
The damaged area must be repaired with the same type of fabric used, the strength must not be reduced and the shape of the cover must not be disturbed by the repair.
Technical standard for ropes used by ZK
Ropes ZK
Steel ropes are used to ensure the load capacity of the entire ZK system is 6 times the maximum take-off weight. Min. the diameter of the lower transverse rope must be min. 3,15 mm.
Marking of ropes
The diameter, limit deviations and strengths are given by the relevant standards. A selection of standards is in Table No. I.
Ropes with a steel core are recommended for the construction of ZK due to their insensitivity to changes in humidity (changes in humidity cause length differences in ropes with a hemp core).
Termination of ropes
The rope ends with an eyelet. The design of eyelets is defined by the standard ČSN 0,24490 Light eyelets for steel ropes.
The eyelet must not break when the rope is loaded at the point of contact with the tongue or screw.
The surface of the socket must resist corrosion. The diameter of the eyelet D must be at least twice the diameter of the rope, the inner length Lt must be min. 2,25 of diameter D - see fig 1.
Design of rope terminations
The termination of the rope can be done by crimped braiding or with sleeves according to ČSN 0,24481.
Two aluminum alloy sleeves are used with the spacing as shown.
Sleeve length Lt is 2 – 2,5 times the diameter of the sleeve dt.
The size of the sleeves is given in table no. 2.
TABLE No. 2.
Semi-finished sleeves are given by the dimensional standard ON 427716 Flat-oval tubes for cable eye sleeves.
Flat-oval tubes are hot-pressed or cold-drawn from soft aluminum alloy, quality 424413.11 and 424400.11. The dimensions of the flat-oval pipes are shown in table no. 3.
TABLE No. 3.
Pressing is carried out under cold static pressure in a suitably adjusted tool - jaws.
Selection from standards for steel ropes
Technical standard for hanging harnesses ZK
Introductory provisions
The harness must ensure a secure connection and attachment of the pilot to the ZK. The risk of injury to the pilot by parts of the harness must be eliminated, especially during an emergency landing. The harness must transfer all resulting loads from the pilot's body as efficiently as possible. The harness must not restrict the pilot during take-off and flight. The pilot falling out of the harness must be excluded in all positions. If the harness is equipped with a rescue system and the system is activated manually, the control handle must be easily accessible without excessive pilot skill.
Fabric materials for supporting parts of harnesses
Fabric materials – synthetic material based on polyamide, polyester or polypropylene materials. Natural materials such as jute, linen, cotton, leather or leatherette may not be used for the supporting parts of the harness.
The main sling must be routed under the pilot's body.
Threads for sewing harnesses
Threads made of synthetic materials (polyamide, polyester) with min. bearing capacity of 70 N and min. avg. 0,3 mm. The ends of the sewn joints must be secured against spontaneous fraying.
The picture shows suitable methods of connecting the straps and sewing the strap to the fabric.
Strength
The harness must withstand a load between strengths of 9 times the maximum permissible weight of the pilot, but at least 900 kg in the normal flight position of the pilot under a load of 2 x 10 sec. It is not permissible to damage any supporting part, such as straps, seams, etc.
The prone harness must have a shoulder hinge stop to prevent the pilot from tipping upside down. This stop (hinge) must withstand a load test of min. 2000 N.
Hanging carabiners, loops
Hanging carabiners must have a certificate for a load of min. 18000 N, must be equipped with a lock with pin and tooth (screwing).
Connecting the straps with self-locking buckles at the supporting parts of the harnesses must be done in such a way as to prevent the end of the strap from being pulled out of the buckle (by bending the end and stitching, etc.)
Type plate
The harness must have a permanent nameplate with the following information:
a) manufacturer
b) type designation
c) production number / year of production
d) LAA CR Type Certificate number
e) max. permissible weight
TITLE 9 Annex 2 ZL2/I
Technical standards for the scope of technical documentation for Type ZK approval
Introductory provisions
This directive establishes the scope of the preparation of the technical documentation necessary for the issuance of the LAA ČR Type Certificate. The following documents are required:
– drawings of the ZK assembly and its adjustment
– drawings of sub-assemblies of individual construction nodes
– production drawing of individual parts of the structure
– drawings of the cover (cuts or unstitched cover from which the similarity with the compared cover can be assessed)
– cover sewing workflow
– strength calculation
– reports on stability and strength tests performed
– protocols on the performed test flights
– a report on the operation of prototypes
– flight and technical manual
Auxiliary Power Unit Requirements = Auxiliary Motor (abbreviation PM) for hang glider
A. In general
1. Definition of Hang glider with auxiliary propulsion unit - auxiliary engine:
– Belongs to the category of motorless hang gliders
– It must be possible to take off with a pilot run
– The weight of the ZK is max. 40 kg
– The auxiliary propulsion unit is not part of the hang glider
– The auxiliary drive unit is part of the pilot harness
– When flying with an auxiliary propulsion unit, only one person may fly on ZK
2. Auxiliary power unit - auxiliary engine:
– The auxiliary drive unit is part of the pilot harness
– The auxiliary drive unit must be technically approved either as a type (TyP) or individually as a prototype
– The auxiliary drive unit must meet the technical and design requirements
– The auxiliary drive unit must have specified limits for use and an operating and technical manual
– The auxiliary drive unit is registered in the SFD register under the name and serial number with the year of manufacture.
3. Forms for PM:
– ZK registration sheet attachment – Hang glider auxiliary propulsion unit.
– Test report of auxiliary unit (PM) to hang glider.
– Protocol on the performance of ZK flight tests with an auxiliary propulsion unit
4. Validity of technical inspection:
The validity of the technical inspection is determined by the relevant ZL technical inspector for a maximum period of 6 years.
B. Design and Construction
1. Auxiliary move. the unit is attached to the pilot suspension harness and includes:
– Connection frame with the pilot's harness
– Engine bed
– Engine with accessories
– Engine control
– Ignition switches
– Pipe with propeller drive shaft
– Propeller drifter
– Propellers
– Auxiliary supports (retractable legs)
The auxiliary power unit and all its components must meet the relevant requirements of UL-2 Part II, SFD Airworthiness Requirements - Powered Hang gliders.
2. Pilot's suspension harness
A suspension harness is a pilot's harness in which the pilot is suspended from the hang glider in flight. A suspension harness in the sense of the airworthiness requirement is a system of straps with a connecting element to the hang glider. If the rescue system container is integrated into the harness, airworthiness requirements apply to all parts of the harness affecting the function of the rescue system in the same sense as for rescue devices. The suspension harness must meet all the requirements of the relevant technical regulation, for example LTF 2008 Lufttuchtigkeitsforderungen fur Hangegleiter und Gleitsegel, or other generally recognized regulations.
The auxiliary drive unit is connected to the pilot's suspension harness by means of a frame inserted into the longitudinal pockets.
The suspension harness includes:
– Cord for tipping
– Closing the harness – zip and its control
– Auxiliary support with their control
– Safety system with locking needle and release
– Engine switch
– safety shutdown of the engine
3. Rescue system
The rescue system is a rescue parachute including a connecting strap, an inner container, a harness attachment and an outer container with elements for attaching the outer container to the harness separate from the harness. Instead of a separate outer container, a usable outer container is integrated into the harness, of which it is a fixed part.
Airworthiness requirements according to the relevant regulation apply to all parts of the harness that affect the function of the rescue device.
C. Flight tests, flight characteristics of ZK with auxiliary propulsion unit
Flight tests and verification of flight characteristics are always performed with a specific auxiliary propulsion unit and a specific hang glider, and the following are verified:
– The method of filling the fuel tank with gasoline, it is checked whether the carrying straps of the harness are not smeared with gasoline.
– Handling of ZK with auxiliary propulsion unit on the ground.
– The position of the pilot above the crossbar on the ground – the length of the connecting strap – the harness.
– Engine control on the ground, shutdown.
– Take-off properties (in light headwinds), ease of flipping from take-off position to lying flight.
– Hinge position on ZK
– Glider response and adding and subtracting engine clearance.
– Optimum rate of climb.
– Flight characteristics in gentle turns.
– Flight characteristics in sharp turns
– Tilting and tilting of auxiliary supports
– Flight characteristics of the ZK with the power unit switched off.
– Stability around the transverse axis.
– Stability around the longitudinal axis.
– Landing properties.
D. Operating Data and Limitations
1. The PM must have an "Operational and Technical Manual" that contains:
– Technical data.
– Operating and maintenance instructions.
– Operation and maintenance records.
2. A hang glider equipped with a PM must have a flight and operations manual that includes, among other things:
– ZK weight without Auxiliary drive unit.
– PM weight including pilot's harness.
– Maximum weight on the ZK hinge.
– Maximum amount of fuel.
