Content last revised: 2010/12/01
Subchapters
 A (522.1522.3)
 B (522.21522.255)
 C (522.301522.597)
 D (522.601522.885)
 E (522.901522.1193)
 F (522.1301522.1449)
 G (522.1501523.1589)
 H (522.1801523.1857)
 J (522.1901523.1947)
Appendices
(2007/12/30)
Subchapter C  Structure
General
522.301 Loads

(a) Strength requirements are specified in terms of limit loads (the maximum loads to be expected in service) and ultimate loads (limit loads multiplied by prescribed factors of safety). Unless otherwise provided, prescribed loads are limit loads.

(b) Unless otherwise provided, the air and ground loads must be placed in equilibrium with inertia forces, considering each item of mass in the glider. These loads must be distributed so as to represent actual conditions or a conservative approximation to them.

(c) If deflections under load would significantly change the distribution of external or internal loads, this redistribution must be taken into account.
522.303 Factor of Safety
Unless otherwise provided, a factor of safety of 1.5 must be used.
522.305 Strength and Deformation

(a) The structure must be able to support limit loads without permanent deformation. At any load up to limit loads, the deformation may not interfere with safe operation. This applies in particular to the control system.

(b) The structure must be able to support ultimate loads without failure for at least three seconds.
However, when proof of strength is shown by dynamic tests simulating actual load conditions, the three second limit does not apply.
522.307 Proof of Structure

(a) Compliance with the strength and deformation requirements of 522.305 must be shown for each critical load condition. Structural analysis may be used only if the structure conforms to those for which experience has shown this method to be reliable. In other cases, substantiating load tests must be made.

(b) Certain parts of the structure must be tested as specified in Sub chapter D of this Chapter.
Note: Structural requirements contained in Subchapter C do not constitute all the structural requirements necessary to show compliance with Chapter 522.
Flight Loads
522.321 General

(a) Flight load factors represent the ratio of the aerodynamic force component (acting normal to the flight path of the glider) to the weight of the glider. A positive flight load factor is one in which the aerodynamic force acts upward, with respect to the glider.

(b) Compliance with the flight load requirements of this Subchapter must be shown:

(1) At each critical altitude within the range in which the glider may be expected to operate; and

(2) At each practicable combination of weight and disposable load.

522.331 Symmetrical Flight Conditions

(a) The appropriate balancing horizontal tail load must be accounted for in a rational or conservative manner when determining the wing loads and linear inertia loads corresponding to any of the symmetrical flight conditions specified in 522.333 through 522.345.

(b) The incremental horizontal tail loads due to manoeuvring and gusts must be reacted by the angular inertia of the glider in a rational or conservative manner.

(c) In computing the loads arising in the prescribed conditions, the angle of attack is assumed to be changed suddenly without loss of flight speed until the prescribed load factor is attained. Angular accelerations may be disregarded.

(d) Aerodynamic data required for the establishment of the loading conditions must be verified by tests, calculations or by conservative estimation.

(1) In the absence of better information the maximum negative lift coefficient in the normal configuration may be taken as 0.8.

(2) If the pitching moment coefficient C_{mo} is less than ±0.025, a coefficient of at least 0.025 must be used for the wing and horizontal tail.
(amended 2007/07/16)

522.333 Flight Envelope

(a) General. Compliance with the strength requirements of this Subchapter must be shown at any combination of air speed and load factor on and within the boundaries of the flight envelopes specified by the manoeuvring and gust criteria of subparagraphs (b) and (c) of this paragraph respectively.

(b) Manoeuvring envelope. Wingflaps in the en route setting, air brakes closed.
(See Figure 1.) 
(c) Gust envelope. Wingflaps in the en route setting. (See Figure 2.)
Figure 2  Gust Envelope

(1) At the design gust speed V_{B}, the glider must be capable of withstanding positive (up) and negative (down) gusts of 15 m/s acting normal to the flight path.
(amended 2007/07/16) 
(2) At the design maximum speed V_{D}, the glider must be capable of withstanding positive (up) and negative (down) gusts of 7.5 m/s acting normal to the flight path.

522.335 Design Air Speeds
The selected design air speeds are equivalent air speeds (EAS):

(a) Design manoeuvring speed V_{A}
where:
V_{S1} = estimated stalling speed at design maximum weight with wingflaps neutral and air brakes retracted.

(b) Design flap speed, V_{F}

(1) For each landing setting, V_{F} must not be less than the greater of:

(i) 1.4 V_{S1}, where V_{S1} is the computed stalling speed with wingflaps neutral at the maximum weight.

(ii) 2.0 V_{SF}, where V_{SF} is the computed stalling speed with wingflaps fully extended at the maximum weight.


(2) For each positive enroute setting, V_{F} must not be less then the greater of:

(i) 2.7 V_{S1}, where V_{S1} is the computed stalling speed at design maximum weight with wing flaps in the particular positive enroute setting.

(ii) 1.05 V_{A}, where V_{A} is determined in accordance with subparagraph (a) of this paragraph, i.e. for wingflaps neutral.


(3) For all other settings, V_{F} must equal V_{D},


(c) Design Gust Speed V_{B}. V_{B} must not be less than V_{A}.

(d) Design Aerotow Speed V_{T}. V_{T} must not be less than 125 km/h.

(e) Design Winchlaunching Speed V_{W}. V_{W} must not be less than 110 km/h.

(f) Design Maximum Speed V_{D}. The design maximum speed may be chosen by the applicant but must not be lower than:
(km/h) for gliders of Category U.
(km/h) for gliders of Category A.
where:
W/S = wing loading (daN/m^{2}) at design S maximum weight.
Cd_{min} = the lowest possible drag coefficient of the glider.
For a powered glider, V_{D} must also not be lower than 1.35 V_{H}.
(Change 5221 (870831))
(Change 5222 (930630))
522.337 Limit Manoeuvring Load Factors
The limit manoeuvring load factors on the Vn diagram (see Figure 1) must have at least the following values:
Figure 1
Category  U  A 

n_{1}  +5.3  +7.0 
n_{2}  +4.0  +7.0 
n_{3}  1.5  5.0 
n_{4}  2.65  5.0 
522.341 Gust Load Factors

(a) In the absence of a more rational analysis, the gust load factors must be computed as follows:
where:
po = density of air at sealevel (kg/m^{3})
U = gust velocity (m/s)
V = equivalent air speed (m/s)
a = slope of wing lift curve per radian
m = mass of the glider (kg)
g = acceleration due to gravity (m/s^{2})
S = design wing area (m^{2})
k = gust alleviation factor calculated from the following formula:
where:
(nondimensional glider mass ratio)
where:
p = density of air (kg/m^{3}) at the altitude considered
l_{m} = mean geometric chord of wing (m)

(b) The value of n calculated from the expression given above need not exceed:
522.345 Loads with Air Brakes and Wingflaps Extended

(a) Loads with air brakes extended

(1) The glider structure including airbrake system, must be capable of withstanding the most unfavourable combination of the following parameters:
Equivalent Airspeed V_{D} (EAS) Air brakes from the retracted to the fully extended position Manoeuvring load factor from –1.5 to 3.5
(amended 2007/07/16) 
(2) The horizontal tail load is assumed to correspond to the static condition of equilibrium.

(3) In determining the spanwise load distribution, changes in this distribution due to the presence of the air brakes must be accounted for.


(b) Load with wingflaps extended. If wingflaps are installed, the glider must be assumed to be subjected to manoeuvres and gusts as follows:

(1) With wingflaps in all landing settings, at speeds up to V_{F}:

(i) manoeuvring up to a positive limit load factor of 4.0;

(ii) positive and negative gusts of 7.5 m/s acting normal to the flight path.


(2) With wingflap positions from the most positive enroute setting to the most negative setting, the manoeuvring conditions of 522.333(b) and the gust conditions of 522.333(c), except that the following need not be considered:
(amended 2007/07/16)
(i) speeds greater than the V_{F} appropriate to the wingflap setting;

(ii) manoeuvring load factors corresponding to points above the line AD or below the line GE of Figure 1.
(amended 2007/07/16)



(c) Speed limiting flaps. If wingflaps are to be used as a dragincreasing device for the purpose of speed limitation (airbrake) conditions specified in 522.345(a) must be met for all wingflap positions.

(d) When an automatic wingflap load limiting device is used, the glider must be designed for the critical combination of air speed and wingflap position allowed by that device.
(Change 5221 (870831))
522.347 Unsymmetrical Flight Conditions
The glider is assumed to be subjected to the unsymmetrical flight conditions of 522.349 and 522.351. 522.351 Unbalanced aerodynamic moments about the c.g. must be reacted in a rational or conservative manner, considering the principal masses furnishing the reacting inertia forces.
522.349 Rolling Conditions
The glider must be designed for the rolling loads resulting from the aileron deflections and speeds specified in 522.455 in combination with a load factor of at least twothirds of the positive manoeuvring load factors prescribed in 522.337.
522.351 Yawing Conditions
The glider must be designed for yawing loads on the vertical tail surface specified in 522.441 and 522.443.
522.361 Engine Torque

(a) The engine mount and its supporting structure must be designed for the effects of:

(1) the limit torque corresponding to takeoff power and propeller speed, acting simultaneously with 75% of the limit loads from flight condition A of 522.333(b);

(2) the limit torque corresponding to the maximum continuous power and propeller speed, acting simultaneously with the limit loads from flight condition A of 522.333(b).


(b) For reciprocating engines the limit torque to be accounted for in 522.361(a) is obtained by multi plying the mean torque by one of the following factors:

(1) 1.33 for engines with 5 or more cylinders;

(2) 2 for engines with 4 cylinders;

(3) 3 for engines with 3 cylinders;

(4) 4 for engines with 2 cylinders;

522.363 Side Load on Engine Mount

(a) The engine mount and its supporting structure must be designed for a limit load factor in a lateral direction, for the side load on the engine mount, of not less than onethird of the limit load factor for flight condition A (1/3n1).

(b) The side load prescribed in (a) may be assumed to be independent of other flight conditions.
522.371 Gyroscopic Loads
For powered gliders of airworthiness Category A, the engine mount and its supporting structure must be designed for gyroscopic loads resulting from maximum continuous r.p.m.
522.375 Winglets

(a) When winglets are installed the glider must be designed for 

(1) The side loads due to maximum sideslip angle of the winglet at V_{A};

(2) Loads resulting from gusts acting perpendicularly to the surface of the winglet at V_{B} and V_{D};

(3) Mutual interaction effects of winglets and wing on aerodynamic loads;

(4) Hand forces on the winglets; and

(5) Loads due to wingtip landing as specified in 522.501, if the winglet can touch the ground.


(b) In the absence of more rational analysis the loads must be computed as follows:

(1) The lift at the winglets due to sideslip at V_{A} 
where: CL_{max} = maximum lift coefficient of winglet profile
SW = area of winglet

(2) The lift of the winglets due to lateral gust at VB and VD 
where: U = lateral gust velocity at the values as described in 522.333(c)
a_{W} = slope of winglet lift curve per radian
k = gust alleviation factor as defined in 522.443(b)
The above described load LW_{g} need not exceed the value

(3) Hand forces of 15 daN must be assumed to act at the tip of the winglet 

(i) In horizontal inboard and outboard direction parallel to the spanwise axis of the wing; and

(ii) In horizontal forward and backward direction parallel to the longitudinal axis of the fuselage.


In addition, the rigging loads as specified in 522.591 must be applied if the winglet plane is not normal to the plane of the wing.
(Change 5222 (930630))
Control Surfaces and Systems
522.395 Control System Loads

(a) Each flight control system, including stops, and its supporting structure must be designed for the loads corresponding to at least 125% of the computed hinge moments of the movable control surfaces in the conditions prescribed in 522.415 through 522.455. In computing the hinge moments reliable aerodynamic data must be used. The effects of tabs must be taken into account. In no case must the loads in any part of the system be less than those resulting from the application of 60% of the pilot efforts specified in 522.397(a).

(b) Pilot forces used for design are assumed to act at the appropriate control grips or pads as they would in flight, and to be reacted at the attachments of the control system to the control surface horns.
(Change 5221 (870831))
522.397 Loads Resulting from Limit Pilot Forces

(a) In addition to 522.395(a) the control systems for the direct control of the glider about its longitudinal, lateral, or yawaxis (main control system) and other control systems affecting flight behaviour and supporting points must be designed to withstand as far as to the stops (these included) limit loads arising from the following pilot forces:
Control Pilot Force
daNMethod Of Force Application Assuming Single Lever Control Systems Elevator
35
Push and pull handgrip of control stick Ailerons
20
Move handgrip of control stick sideways Rudder
90
Apply forward pressure on one rudder pedal Air brakes 35 Push and pull handgrip of control lever Spoilers Wngflaps
Towing cable
35
Pull control handle release 
(b) the rudder control system must be designed to a load of 100 daN per pedal acting simultaneously on both pedals in forward direction.
(Change 5221 (870831))
522.399 Dual Control Systems
Dual control systems must be de signed for:

(a) the pilots acting together in the same direction; and

(b) the pilots acting in opposition, each pilot applying 0.75 times the load specified in 522.397(a).
522.405 Secondary Control Systems
Secondary control systems such as those for landing gear retraction or extension, trim control, etc., must be designed for supporting the maximum forces that a pilot is likely to apply to those controls.
522.411 Control System Stiffness and Stretch

(a) The amount of movement available to the pilot of any aerodynamic control surface may not, in any condition of flight, be excessively reduced by elastic stretch of the control circuits.
If there are cables in the system and tension can be adjusted, the minimum value must be used for demonstrating compliance with all appropriate requirements. 
(b) For cable operated systems, the allowable rigging tension in the cables must be established, taking into consideration the variations in temperature (see 522.689) which may occur.
(Change 5221 (870831))
522.415 Ground Gust Conditions
The control system from the control surfaces to the stops or when installed the arresting devices must be designed for limit loads corresponding to hinge moments calculated from the expression:
M_{R}= k l_{R} S_{R} q
where:
M_{R} = limit hinge moment
l_{R} = mean chord of control surface aft of hinge line
S_{R} = area of control surface aft of hinge line
q = dynamic pressure corresponding to an air speed of 100 km/h
k = limit hinge moment factor due to ground gust, taken from the following table:
Control Surface 
K  Remarks 

Aileron  ±0.75  Control column secured in midposition 
±0.50  Ailerons at full travel: + moment at the one, moment at the other aileron  
Elevator  ±0.75  Elevator fully up () or fully down (+) or in the position in which it can be locked 
Rudder  ±0.75  Rudder at full travel right or left, or locked in neutral 
Horizontal Tail Surfaces
522.421 Balancing Loads

(a) A horizontal tail balancing load is the load necessary to maintain equilibrium in any specified flight condition with no pitching acceleration.

(b) The horizontal tail must be designed for the balancing loads occurring at any point of the limit manoeuvring envelope and in the airbrake and wingflap positions as specified in 522.333 and 522.345.
522.423 Manoeuvring Loads
The horizontal tail must be designed for the most severe loads likely to occur in pilotinduced pitching maneuvers, at all speeds up to V_{D}.
(amended 2007/07/16)
522.425 Gust Loads
In the absence of a more rational analysis, the horizontal tail loads must be computed as follows:
where:
P = horizontal tail load (N)
Po = horizontal tail balancing load acting on the horizontal tail before the appearance of the gust (N)
po = density of air at sealevel (kg/m^{3})
S_{t} = area of horizontal tail (m^{2})
a_{h} = slope of horizontal tail lift curve per radian
U = gust speed (m/s)
k_{H} = gust factor. In the absence of a rational analysis the same value may be taken as for the wing.
V = speed of flight (m/s)
= rate of change of downwash angle with wing angle of attack
(Change 5221 (870831))
522.427 Unsymmetrical Loads for Powered Glider
The slipstream effect on fixed surfaces and on rudder loads must be accounted for if such loading is to be expected.
(Change 5221 (870831))
Vertical Tail Surfaces
522.441 Manoeuvring Load
The vertical tail surfaces must be designed for manoeuvring loads imposed by the following conditions:

(a) At speed the greater of V_{A} and V_{T}, full deflection of the rudder.

(b) At speed V_{D}, onethird of full deflection of the rudder.
522.443 Gust Loads

(a) Vertical tail surfaces must be designed to withstand lateral gusts to the values described in 522.333(c).

(b) In the absence of a more rational analysis, the gust load must be computed as follows:
where:
P_{f} = gust load (N)
av = slope of vertical tail lift curve per radian
S_{f} = area of vertical tail (m^{2})
r_{o} = density of air at sealevel kg/m^{3})
V = speed of flight (m/s)
U = gust speed (m/s)
k = gust factor, should be taken as 1.2
Supplementary Conditions for Tail Surfaces
522.447 Combined Loads on Tail Surfaces

(a) The unsymmetrical distribution of the balancing load on the horizontal tail which arises in flight conditions A and D of the Vn envelope shall be combined with the appropriate manoeuvring load on the vertical surface as specified in 522.441 acting in such a direction as to increase the rolling torque.

(b) 75% for Category U and 100% for Category A of the loads according to 522.423 for the horizontal tail and 522.441 for the vertical tail must be assumed to be acting simultaneously.
(Change 5222 (930630))
522.449 Additional Loads Applicable to Vtails
A glider with Vtail, must be designed for a gust acting perpendicularly with respect to one of the tail surfaces at speed V_{B}.
Ailerons
522.455 Ailerons
The ailerons must be designed for control loads corresponding to the following conditions:

(a) at speed the greater of V_{A} and V_{T} the full deflection of the aileron; and

(b) at speed V_{D}, onethird of the full deflection of the aileron.
Ground Loads
522.471 General
The limit ground loads specified in this Subchapter are considered to be external loads and inertia forces that act upon a glider structure. In each specified ground load condition, the external reactions must be placed in equilibrium with the linear and angular inertia forces in a rational or conservative manner.
522.473 Ground Load Conditions and Assumptions

(a) The ground load requirements of this Subchapter, must be complied with at the design maximum weight.

(b) The selected limit vertical inertia load factor at the c.g. of the glider for the ground load conditions prescribed in this Subchapter:
(amended 2007/07/16)
(1) may not be less than that which would be obtained when landing with a descent velocity of 1.77 m/s;
(amended 2007/07/16) 
(2) may not be less than 3.
(amended 2007/07/16)


(c) Wing lift balancing the weight of the glider may be assumed to exist throughout the landing impact and to act through the c.g. The ground reaction load factor may be equal to the inertia load factor minus one.
522.477 Landing Gear Arrangement
522.479 through 522.499 apply to gliders with conventional arrangements of landing gear. For unconventional types it may be necessary to investigate additional landing conditions depending on the arrangement and design of the landing gear units.
(Change 5221 (870831))
522.479 Level Landing Condition

(a) For a level landing, the glider is assumed to be in the following attitude.

(1) For gliders with a tail skid and/or wheel, a normal level flight attitude.

(2) For gliders with nose wheels, attitudes in which 

(i) The nose and main wheels contact the ground simultaneously; and

(ii) The main wheels contact the ground and the nose wheel is just clear of the ground.



(b) The main gear vertical load component P_{VM} must be determined to the conditions in 522.725.

(c) The main gear vertical load component P_{VM} must be combined with a rearward acting horizontal component P_{H} so that the resultant load acts at an angle of 30° with the vertical.
(amended 2007/07/16) 
(d) For gliders with nose wheels the vertical load component P_{VN} on the nose wheel in the attitude of subparagraph (a)(2)(i) of this paragraph must be computed as follows and must be combined with a rearward acting horizontal component according to subparagraph (c) of this paragraph taking into account 522.725(a):
(amended 2007/07/16)P_{VN} = 0.8 mg
where:
m =mass of glider (kg)
g =acceleration of gravity (m/s^{2}).
(Change 5221 (870831))
522.481 Taildown Landing Conditions
For design of tail skid and affected structure and empennage including balancing weight attachment, the tail skid load in a tail down landing (main landing gear free from ground) must be calculated as follows:
where:
P = tail skid load (N)
m = mass of the glider (kg)
g = acceleration of gravity (m/s^{2})
i_{y} = radius of gyration of the glider (m)
L = distance between tail skid and glider c.g. (m)
(Change 5221 (870831))
522.483 Onewheel Landing Condition
If the two wheels of a main landing gear arrangement are laterally separated, the conditions under 522.479(a)(2), (b) and (c) must be applied also to each wheel separately taking into account limiting effects of bank. In the absence of a more rational analysis the limit kinetic energy must be computed as follows:
(amended 2007/07/16)
A = ½ m_{red} V_{v}^{2}
where:
V_{v} = rate of descent
(amended 2007/07/16)
m =mass of the glider (kg)
a = half the track (m)
i_{x} =radius of gyration of the glider (m)
(Change 5221 (870831))
522.485 Side Load Conditions
A side load acting on one side of the main landing gear (both from right and left) normal to the plane of symmetry at the centre of the contact area of the tire or skid with the ground, must be assumed. The applied load is equal to 0.3 P_{V} and must be combined with a vertical load of 0.5 P_{V} where P_{V} is the vertical load determined in accordance with 522.473.
(amended 2007/07/16)
522.497 Tail Skid Impact

(a) Except as provided in (b), if the c.g. of the unloaded glider in side view is situated behind the ground contact area of the main landing gear, the rear portion of the fuselage, the tail skid and the empennage must be designed to withstand the loads arising when the tail landing gear is raised to its highest possible position, consistent with the main wheel remaining on the ground, and is then released and allowed to fall freely.

(b) If the c.g. in all loading conditions is situated behind the ground contact area of the main landing gear (a) need not be applied.
522.499 Supplementary Conditions for Nose Wheels
In determining the ground loads on the nose wheel and affected supporting structures, and assuming that the shock absorber and tyre are in their static positions, the following conditions must be met:

(a) For forward loads, the limit force components at the axle must be:

(1) A vertical component of 2.25 times the static load on the wheel; and

(2) A forward component of 0.4 times the vertical component.


(b) For side loads, the limit force components at the ground contact must be:

(1) A vertical component of 2.25 times the static load on the wheel; and

(2) A side component of 0.7 times the vertical component.

(Change 5221 (870831))
522.501 Wingtip Landing
There must be means to ensure that ground loads acting at the wing tips are adequately resisted. A limit load T=40 daN must be assumed to act rearward at the point of contact of one wingtip with the ground, in a direction parallel to the longitudinal axis of the glider, the yawing moment so generated must be balanced by side load R at the tail skid/wheel or nose skid/wheel (see Figure 4).
(Change 5221 (870831))
Emergency Landing Conditions
522.561 General

(a) The glider although it may be damaged in emergency landing conditions must be designed as prescribed in this paragraph to protect each occupant under those conditions.

(b)The structure must be designed to give each occupant every reasonable chance of escaping serious injury in a crash landing when proper use is made of belts and harnesses provided for in the design, in the following conditions:

(1) The occupant experiences, separately, ultimate inertia forces corresponding to the accelerations shown in the following:
Upward 7.5 g
(amended 2010/05/27)Forward 15.0 g
(amended 2010/05/27)Sideward 6.0 g
(amended 2010/05/27)Downward 9.0 g
(amended 2010/05/27) 
(2) An ultimate load of 9 times the weight of the glider acting rearwards and upward at an angle of 45^{o} to the longitudinal axis of the glider and sideward at an angle of 5^{o }acts on the forward portion of the fuselage at a suitable point not behind the pedals.
(amended 2010/05/27)


(c) Each glider with a retractable landing gear must be designed to protect each occupant in a landing with wheel(s) retracted under the following conditions:

(1) a downward ultimate inertia force corresponding to an acceleration of 3g;

(2) a coefficient of friction of 0.5 at the ground.


(d) Except as provided in 522.787, the supporting structure must be designed to restrain, under loads up to those specified in subparagraph (b)(1) of this paragraph each item of mass that could injure an occupant if it came loose in a crash landing.
(amended 2010/05/27) 
(e) For a powered glider with the engine located behind and above the pilot’s seat, an ultimate inertia load of 15g in the forward direction must be assumed.
(Change 5221 (870831))
Towing and Launching Loads
522.581 Aerotowing

(a) The glider must be initially assumed to be in stabilized level flight at speed V_{T} with a cable load acting at the launching hook in the following directions:

(1) horizontally forwards;

(2) in plane of symmetry forwards and upwards at an angle of 20° with the horizontal;

(3) in plane of symmetry forwards and downwards at an angle of 40° with the horizontal; and

(4) horizontally forwards and sidewards at an angle of 30° with the plane of symmetry.


(b) With the glider initially assumed to be subjected to the same conditions as specified in 522.581(a), the cable load due to surging suddenly increases to Q_{nom} assuming the use of a textile rope.
(amended 2007/07/16)
(1) The resulting cable load increment must be balanced by linear and rotational inertia forces. These additional loads must be superimposed on those arising from the conditions of 522.581(a).

(2) Q_{nom} is the rated ultimate strength of the towing cable (or weak link if employed). For the purpose of these requirements it must be assumed to be at not less than 1.3 times the glider maximum weight and not less than 500 daN.

522.583 Winchlaunching

(a) The glider must be initially assumed to be in level flight at speed V_{W} with a cable load acting at the launching hook in a forward and downward direction at an angle ranging from 0° to 75° with the horizontal.
(amended 2007/07/16) 
(b) The cable load must be determined as the lesser of the following two values:

(1) 1.2 Q_{nom} as defined in 522.581(b), or
(amended 2007/07/16) 
(2) the loads at which equilibrium is achieved, with either:

(i) the elevator fully deflected in upward direction, or

(ii) the wing at its maximum lift.
A horizontal inertia force may be assumed to complete the equilibrium of horizontal forces.



(c) In the conditions of 522.583(a), a sudden increase of the cable load to the value of 1.2 Q_{nom} as defined in 522.581(b), is assumed. The resulting incremental loads must be balanced by linear and rotational inertia forces.
(amended 2007/07/16)
522.585 Strength of Launching Hook Attachment

(a) The launching hook attachment must be designed to carry a limit load of 1.5 Q_{nom}, as defined in 522.581(b), acting in the directions specified in 522.581 and 522.583.
(amended 2007/07/16) 
(b) The launching hook attachment must be designed to carry a limit load equal to the maximum weight of the glider, acting at an angle of 90° to the plane of symmetry.
Other Loads
522.591 Rigging and Derigging Loads
A rigging limit load of plus and minus twice the wingtip reaction, determined when either a semispan wing is simply supported at root and tip or when the complete wing is simply supported at the tips, where this would be representative of the rigging procedure, must be assumed to be applied at the wing tip and reacted by the wing when supported by a reaction and couple at the wing root.
(Change 5221 (870831))
522.593 Hand Forces at the Horizontal Tail Surfaces
A limit hand force of 3% of the design maximum weight of the glider but not less than 15 daN must be assumed to act on either tip of the horizontal tail surface:

(a) in the vertical direction;

(b) in the horizontal direction, parallel to the longitudinal axis.
(Change 5221 (870831))
522.595 Load on the Attachment Point of the Parachute Ripcord
The attachment point for the parachute ripcord (if provided) must be designed for a limit load of 300 daN acting in all possible directions.
522.597 Loads from single masses
The attachment means for all single masses, which are part of the equipment of the glider, must be designed to withstand loads corresponding to the maximum design load factors to be expected from the established flight and ground loads.