NOTICE Amendments to this manual will be priced and sold individually by the Superintendent of Documents. A status sheet listing the amendments and their prices will be sent periodically to interested purchasers of this, manual, If you wish to receive these notifications, please fill out the form be- low and return it to the Superintendent of Documents, SOT LIBRARY, FOR 10-8 40 TECHNICAL UNIT aye 291983 DOT LIBRARY mag3.2 ‘TO: Superintendent of Documents Government Printing Office Washington 25, D.C. Please send me all notifications regarding amend Manuals. (s to Civil Aeronautics Name. Address (Siret) a) (Site)INTRODUCTORY NOTE This manual contains in consolidated form (1) Civil Air Regulations Part 4a, Airplane Airworthiness, dated April 7, 1960, and Amendment 44-13 and (2) the rales, policies, and interpretations issned by the Administrator of the Federal Aviation Ageney in application to the various sections of the regulations. FAA ries are supplementary regulations issued pursuant to authority expressly conferred on the Administrator in the Civil Air Regulations, Such rales are mandatory and must be complied with. FAA policies provide detailed technical information on recommended methods of complying with the Civil Air Regulations. Such policies are for the guidance of (he public nnd axe not manslatory in nature, FAA interpretations define or explain words and phrases of the Civil Air Regulations, Such interpretations are for the guidance of the public and ‘will be followed by the Agency in determining compliance with the regulations. ‘This manual is arranged to give the number, title, and text of each seetion of the regulations followed by any rales, policies, or interpretations applicable to that, section. These rules, policies, or interpretations of the Administrator are identified by consecutive dash numbers wppended to the regulation section ‘number ‘As amendments and other pertinent materials pertaining to Part 4a are issued, they will be included in this manual,igo LIBRARY #08 1G-A Contents Subpart A— Airworthiness Requirements General Scope. Airplane Airworthiness and Type Cert Requirements for issuance. Data required for airwort Tata required for type en Inspection and tests Approval of eireraft component (FAA rules which apply to t2¢. 4.31) Subpart B—Definitions Weights... Structural terms. Air density, p.. Speed... Design yunt velvliy, U. Dynainie pressure, Load factors. Aerodynamic coetielents, Cz, Cx, OP, ete Standard atmosphere (standard air)... Primary structure Subpart C—Structural Loading Conditions General Structural Requirements Strength. Deformations. Sines seereecaeinen Proof of strength and rigidity Materials, fabrication, protetion, ee 4a63 4085,convents, Flight Loads General Air speeds... fara. Gust load factors... Factors of safety. Symmetrical Flight Conditions (Flaps Rerracted) 5m I (postive high angle of stack) Condition I (ostie high angle of stack modied) Condition Tt (negative high angle ofatse) Conatdon Monnet my Condition 1V (negaiive low angle of attack) Condition V (inverted ght) = Symmetrical Flight Canditians (Flaps or Auxiliary Devices in Operation) Condition VIM (negative gust, laps deflected) -- Condition 1X (dive. flaps deflected). Unsymmetrieal Flight Conditions Liftewire-cut Dragewire-cut_- : ‘Unsymmetrieal propeller thrust Wing tanks empty... Wing Load Distribution Wing toaa aistribation. Control Surface Loads 4a... Damping (horizontal surfaces) ‘Tab effects (horizontal surfaces) < dat19aM a CONTENTS: Vertical Tail Surfaces Maneuvering Damping (vertieal surfaces) Gusts (vertical surfaces) Wing flaps. Taps. Special Devices Special devices... : General Control wires or push roda._ Blovator eystems. i Rudder systems Alleron syzteme.. Flap and tab control systems. Control System Loads General ____ Level tnading aa ‘Three-point landing. Energy absorption... Side load. ‘One-whee! innding. Braked landing. Side loads on tail wheat of 4a.t61....- Float Seaplanes Landing with inclined reactions (Goat seaplanes).. Float aitechment members... : Landing with vertical reactions (Goat seaplanes). Safety factors. : Landing with side Toad (float seaplan Local bottom pressures. Distributed bottom pressures. ‘Step fouling condition Bow loading condition ‘Stern Ionding condition... ‘Side loading conditio a 3Ba convents Seaplane Float Loads ‘Seaplane float loads. ‘Seaplane float bottom loads. Wing-Tip Float Loads ‘Sen wing foads.. daar. Engine torque. ‘Migh angle of attack and torque. Engine mounts, nacelle, ete ‘Side lond on engine mount. Up load on engine mount... Passonger leads... Safety belt lande ‘Axial load Joint slippage in wood beams. Bolt holes. Box beams: 1B 15 18 16 16CAM da CONTENTS Drag Trusses ae 20 20 20 20 20 » Nonparallel wires. 20 Tail and Control Surfaces Proof of tail and control surfaces 20 Vibration tests... --.--- 2 Proof of control systems. a Control system tests. = 2 Operation test. a ‘Control system joints a Proof of landing gear 2 Energy absorption tests. a Proof of hulls and floats. eee a Fuselages and Engine Mounts Proof of fuselages and engine mounts : a Clin! cotmn londe 2 2 a 2 2 SUBPART E—Detail Design and Construction General... Materials, Workmanship, and Fabrication Methods Sear ieee eee EEE co M301 ‘Materials and workmanship. 22 Fabrication methods. Stig. Gluing. a Torch welding. 22 Bleetrie welding. aeltaa Brazing and soldering. 2 Protect 28 Inspection Esvin CONTENTS Joints, Fittings, and Connecting Purts Joinis, mcangs, and connecting parts. Bole, pins, and serews. Wood screws... Bycholto. ‘Wire anchorages. =~ Counter wire sizes. Flutter Prevention General futter prevention measures... 42.328... Detail Design of Wings External bracing. Wire-braced menoplanes.. Internally braced biplanes. Fabrie covering ‘Metal-covered wings Detail Design of Tail and Control Surfaces Flap controls Pap controle ‘Tab controls. Spring devices. Single-eable controls Control syetem locks. ‘Trim controls CAM 4a 23 23 28 23cant 42 ‘CONTENTS Detail Design of Landing Gear Hulls and Floats 2 27 27 2 2% 8 Ps 28 28 28 i ft » Operation information and limitations____ 29 Windows and windstelds. 2 20 : 29 2 Opening between pilot comparinient and passengers” cabin 29 Passenger and Baggage Compartments Passenger compartments 2 Passenger chars 2 ‘Baggage compartive 2 Reinforcement Near Propellers Reinforcement near propeller i 0 Subpart F—Eyuipuent 20 3 “Approval af aircraft componcits (FAA Fale wBichappiy Yo see fab2i)-— dnS2e-i 30 Life preserver of flotation device. 30 Pre eathnguahing apparat 30 Non-Air Carrier (NAC) Airplanes Noneair carter (NAG) airplanes. 20 al contact day ying (within 100 males of a Sized base). 30 ‘sual contact day fying (limited detan n NAC landplanes; visual contact aight fying... at Instrument day ying. a Instrument night fying 2 [NAC seaplanes and amphibians. 2CONTENTS Air-Carrier Airplanes; Passenger (ACP) ACP seaplunes and amphibians Installation Requirements Instaiaion requirements. Conan eseeeoneeee Instrument Installation Instruments. Air-speed indicator : Power plant instruments and controls... Fuel quantity gauge: ‘Magnetic compass. Navigational instruments. ‘Gyroscopic instruments. Safety belts Fire extinguishers. Safety belt signal Position lights. ‘Master switch. Propellers oe Conirollabie piteh. Propeller clearance. anor CAM 4a 38 38 33 33 33 33 Ey a 34 3 34 34 35, seesCaM 4a CONTENTS: Fuel Systems Pan Capacity and feed.. 36 ‘Tank installation 236 ‘Tank constructio 38 ‘Tank strength. a7 Gauge. a7 Lines and ftings.—- at 37 BH ay Doar sr Filer openings... -----------~ ‘Prevention of ce formation. General... ‘Tank instalation ‘Tank strength. Oil temperature. --- : Filler openings. Filler openings. Power Plant Instruments, Controls, Accessories Instruments. Controle... ‘Theottle controls 39 = 39 30 40 Engine cowiing—_ Fire wall. 0CONTENTS AN ts Subpart H—Performance rae 0 » 0 10 0 Conirtlability atthe stall. 40 Balanee---- a a a a Flatter and vibration a ‘Ground and water characteristics a Modified Performance Requirements Modified performance requirements for multiengine airplanes not certif- ‘he transport etegery..---- _ 8 Performance Tests General... init 2 Plight test allot. 2 2 2 8 8 8 3 3 Aired Indfeatorealbraton. 8 (Check of fuel system. nas ven cvens a 8 Air Carrier Aircraft Performance Characteristics Performance characteristics of ai carrer airerat. : ant. Weigh - 4.720. “ New production aiceraft—empty weight and eg deteraination (PAA polices whieh apply lo se. 40.783) MT. a Provlfonal weight (alr carrier airplanes). diag roleec as Center of gravity limitations. Taam at ‘New production sircraft—empiy weight and eg. determination (PAA ‘otc which apply ta ex. 40°72), i SAAT ace eae TC aere 6 Transport Category Airplane Performance Requirements Performance requirement for transport eategory airplanes a Mat ‘Minikmamy requirements for cetBeation, COU eer. 4s Definitions 45 6OAM én ‘CONTENTS xu Aa... 46 TTT ara. 6 46 46 46 a a a a ‘Temperature accountability <= 20 202222000020 8 Landing determination. i 8 Flight charaeteristies === nnn oAMTSI-T... 48. Controllability and maneuverability 8 5 Teena ee ee 9 Stability. 7 9 State longitudinal stability © Specific stability condition 50 Dynamic longitudinal stability 50 Directional and lateral static stability 50 Stalling 50 Airplane operating manval 51 ‘ieplane Might: manusls (PAA policies which apply to see. 60.7607) 7 SUBPART I—Miscellaneous pemucemente Identification plate. a Standard weights 3 Leveling means... 5 - 8 61 ‘SR-809B, Provisional Maximum Certificated Weights for Certain Airplanes Operated by Alaskan Air Carriers, Alaskan Air Taxi Operators, and the Depart ment of the Interior. a3 SR.407. Basis for Approval of Lockheed L-18. 65 ‘SR-AIIA. Trisl Operation of Transport Category Airplanes in Cargo Service at In- ‘creased Zero Fuel and Landing Weights. SR-428, Performance Credit for Transport Cateor? ‘Airplanes Bauioped with, Stand- by Power. nAirplane Airworthiness Subpart A—Airworthiness Requirements Note: Current application for airworthiness and type certificates are not processed under this part, but are processed under other airworthiness parts. At resent this part primarily governs modification of air- ‘aft which were originally certificated under Part 4a. Unless otherwise provided, all references to other parts of this subchapter are those provisions in effect ‘on September 28, 1947, General 4a Scope. The airworthiness require- ments set forth in this part shall be used asa basis for obtaining airworthiness or type certitieates: Provided, ‘That: (a) Deviations from the requirements of this part which, in the opinion of the Administrator, insure the equivalent condition for safe operation and, (b) equivalent requirements of the United States Army or Navy with respect to air- worthiness may be accepted in liew of the requirements set forth in this part. Unless otherwise specified an amendment to this part will apply only to airplanes for which applications for type eertifieatesare received subsequent to the effective date of such amendment, 42.2 Airplane categories. (a) At the eleetion of the applicant, an airplane may be certificated under the re- quirements for a particular eategory accord- ing to the intended use of the airplane. Sections of this part which affect only one particular category are designated by a suffix added to the appropriate section numbers, as follows: (6) All sections not designated by a suffix are applicable to all categories, exeept as otherwise specified. 518836 0502 Airworthiness and Type Certificates 4a15 Requirements for issuance. The irworthiness requirements specified in this part shall be used as.a basis for the eertifica- tion of airplanes: Provided, That an airplane manufactured in aceordance with, and con- forming to, the currently effective aircraft specifications issued therefor will be eligible for an airworthiness certificate, if the Ad- ministrator determines such airplane is in condition for safe operation: Provided, further, That an airplane which has not demonstrated compliance with the airworthi- ness requirements specified in this part but which, in the opinion of the Administrator, is in condition for safe operation for experi- mental purposes or for particular activities will be eligible for an airworthiness cer- tificate, 4a16 Data required for airworthiness certificate. When an airworthiness certif iecate is sought and a type certificate is not involved, data which are adequate to estab- lish compliance of the aireraft with the re- quirements listed in this part shall be sub- mitted to the Administrator, 4al7 Data required for type certificate. Data which are adequate to establish com- pliance of the aircraft with the airworthiness ‘requirements listed in this part and which are adequate for the reproduction of other air- planes of the same type shall be submitted to the Administrator. The procedure for sub- mitting the required data, the technieal con- tents of such data, and the methods of testing aireraft with respect to the prescribed ai worthiness requirements shall be in accord- ance with Civil Aeronauties Manual 4, Air- plane Airworthiness.2 AIRPLANE AIRWORTHINESS 4a18 Inspection and tests. Authorized representatives of the Administrator shall have access to the airplane and may witness or conduct such inspections and tests as are deemed necessary by the Administrator. 4a.19 Flight tests. (Applicable to all air- planes certificated as a type on or after May 15,1947.) After proof of compliance with the structural requis contained in this part, and upon completion of all necessary inspection and testing on the ground, and proof of the conformity of the airplane with the type design, and upon receipt from the applicant of a report of fight tests conducted by him, there shall be conducted such official flight tests as the Administrator finds neces- sary fo determine compliance with Subparts ©-G. After the conclusion of these fight tests such additional fight tests shall be con- dueted as the Administrator finds necessary to ascertain whether there is reasonable assurance that the airplane, its components, and equipment are reliable and function properly. The extent of such additional flight tests shall depend upon the complexity. of the airplane, the number and nature of now design features, and the record of pre- vious tests and experience for the particular airplane model, its components, and equip- ment. If practicable, the flight tests per- formed for the purpose of ascertaining the reliability and proper functioning shall be conducted on the same airplane which was used in flight tests to show compliance with Subparts C-@. 42.20 Procedure for type certifention. Acceptable procedures for type certification are outlined in Civil Aeronautics Manual 4. ‘Changes 4a25 Continued compliance. Changes to certificated aircraft shall be substantiated to demonstrate continued compliance of the air- craft with the pertinent airworthiness requirements. 4026 Minor changes. Minor changes to airplanes being manufactured under the terms of a type certificate and which obvi- ously do not impair the eandition af the air- plane for safe operation may be approved by CaM 40 authorized representatives of the Adminis: trator prior to submittal to the Adminis. trator of any required revised drawings. ‘The approval of such minor changes shall be based on the airworthiness requirements in effect when the particular airplane model was originally certificated, unless, in the opinion of the Administrator, compliance with current airworthiness requirements is necessary. 42.27 Major changes, Major changes to airplanes being manufactured under the terms of a type certificate may require the issuance of a new type certificate and the Administrator may, in his discretion, require such changes to comply with current air- worthiness requirements. 4228 Changes required by the Adminis- trator. (a) In the case of aircraft models ap- proved under the airworthiness require- ments in offect prior to the currently effective regulations, the Administrator may require that aireraft submitted for original air- worthiness certification comply with such portions of the currently effective regula- tions as are considered necessary. (b) AM aircraft certificated under the transport category, the manufacture of which is completed after September 30, 1947, shall comply with the following sections of part 4b of this subchapter, as amended: sec- tions 4b.58, 4b.442, 4b495(a), 4.447, 46.478, {b.848, 4b.503(€), 4b516-4b518, 46.556, 4b.557, 416.560, 4b.561, 4.586, 4b.621-1b.621, 4b.651- 4b.655 and 4b.661-10.676. Approval of Materials, Parts, Processes, and Appliances 4a.31 Specifications. (a) Materials, parts, processes, and ap- pliances shall be approved upon a basis and in a manner found necessary by the Admin- istrator to implement the pertinent provi- sions of the Civil Air Regulations. The Ad. ministrator may adopt and publish such specifications as he finds necessary to ad- minister this section, and shall incorporateCAM 4a therein such portions of the aviation indus- try, Federal, and military specifications re- specting such materials, parts, processes, and appliances as he finds appropriate. (b) Any material, part, process, or appl ance shall be deemed to have met the require- ments for approval when it meets the pertinent specifications adopted by the Ad- ministrator. and the manufacturer so cer- AIRPLANE AIRWORTHINESS 3 tifies in a manner prescribed by the Administrator. 4aB1-1 Approval of aircraft components (PAA miles whieh apply to sec. 4a81). Air- craft components, made the subject of ‘echnical Standard Orders, shall be approved upon the basis and in the manner provided in Part 514 of this title. Supp. 9.18 FR, oTt, Jan, 25, 39517 Subpart B—Definitions 4a3T Weights. (a) Weight, W. ‘The total weight of the airplane and its contents. (b) Designed weight. The weight of the airplane assumed for purposes of showing complianee with the structural requirements specified in this part. (©) Minimum design weight. Weight empty with standard equipment, plus crew, plus fuel of 0.25 pound per maximum (except take-off) horsepower, plus oil asper capacity. (@) Standard weight, The maximum weight for which the airplane is certificated as complying with all the airworthiness re- quirements for normal operations. (©) Provisional weight, The maximum weight for which the airplane is certificated as complying with the airworthiness require- ments as modified for scheduled air carriers in section 42.687. 4438 Structural terms, (a) Design wing area, S. ‘The area en- closed by the projection of the wing outline, including ailerons and flaps but ignoring fairings and fillets, on a surface containing the wing chords. The outline is assumed to extend through nacelles and through the fuselage to the plane of symmetry. (b) Design power, P. ‘The total engine horsepower chosen for use in determining the maneuvering load factors. ‘The correspond- ing engine output will be incorporated in the aireraft certificate as a maximum opera- tional limitation in all fight operations other than take-off or climbing flight (see sec. 4a.727). (c) Design wing loading, W/S. ‘The design weight (see, 1.37(b)) divided by the design wing area (see. 4a.38(a)). (a) Design power loading, W/P. The de- sign weight (see. 4a.87(b)) divided hy the de power (see sec. 4a.38(b) and Fig. 42-2). 439” Air density, p. The mass density of the air through which the airplane is moving, in terms of the weight of a unit volume of air divided by the acceleration of gravity. ‘The symbol p, denotes the mass denity of air at sea level under standard atmospheric con- ditions and has the value of 0.002378 slugs per ‘eubie foot. Cross Reference: For definition of standard atmos here, see see. 45. 440 Speed. (a) True air speed, V. The velocity of the airplane, along its fight path, with re- spect to the body of air through which the airplane ie moving. (b) Indicated air speed, V. The true air speed multiplied by the term Vole. (See ‘see. 4a.39.) (c) Design level speed, Vi, The indicated air speed chosen for use in determining the pertinent structural loading conditions. This value will be incorporated in the air- craft certificate as a maximum operational Timitation in Ievel and climbing flight (see ‘see, 42.726), (a) Design gliding speed, V, The maxi- mum indieated air speed to be used in deter- mining the pertinent structural loading con- ditions (see secs. 4a.73 and 42.726). (e) Design stalling speed, V. The com- puted indicated air speed in unaccelerated flight based on the maximum lift coefficient of the wing and the design gross weight.4 AIRPLANE. AIRWORTHINESS ‘The effects of slipstreams and nacelles shall be neglected in computing V,. When high- lift devices are in operation the correspond- ing stalling speed will be denoted by Vy. () Design flap speed, V;, The indicated air speed at which maximum operation of high-lift devices is assumed (see secs. 42.73 and 44.726), (@) Maximum vertical speed, Vu. A fietic tious value of indicated air speed computed for unaccelerated flight in a vertical dive with zero propeller thrust. (h) Design maneuvering speed, V,. The indicated atr speed at which maximum opera- tion of the control surfaces is assumed (see see. 44.73), 4a.d1 Design gust velocity, U. A specific ust velocity assumed to act normal to the flight path, (See sec. 42.76.) 4a42 Dynamic pressure, a. energy of a unit volume of ai aa Yip¥ et Gin terms of true air speed). jsV" Cn terms of indicated air speed). *AS1 pounds per square foot, when V is miles ‘er hour indicated air speed, Cross Reference: For definition of p see see. 4.38 4243 Load factors—(a) Load factor or acceleration tactor, n. ‘the ratio of a load to the design weight. When the load in ques- tion represents the net external load acting on the airplane in a given direction, n repre- sents the aeceleration factor in that. di tion. (b) Limit toad. A toad (or load factor, or pressure) which it is assumed or known may be safely experienced but will not be ex- ceeded in operation. (e) Factor of safety, j. A factor by which the limit loads are multiplied for various de- sign purposes. (@) Ultimate factor of safety, ju Aspeci- fied factor of safety used in determining the maximum load which the airplane structure is required to support. (e) Yield factor of safety, jn A specified factor of safety used in connection with the prevention of permanent deformations. ‘The kinetic CaM 4a (f) Ultimate load. A limit load multi- plied by the specified ultimate factor (or fae~ tors) of safety. (See definition in this see- tion and sec. 4a.61.) (g) Yield load. A limit load multiplied by the specified yield factor (or factors) of safety. (See definitions in this section and ‘see, 42.62.) (h) Strength test. A static load test in which the ultimate loads are properly applied. (See sees. 4a.61 and 42.230(b)). Gi) Proof test. A static load test in which the yield loads are properly applied for a period of at least 1 minute, (See see. 4a.62.) (i) Balancing loads. Loads by which the airplane is placed in a state of equilibrium under the action of external forces resulting from specified loading conditions. ‘The state of equilibrium thus obtained may be either real or fictitious. Balancing loads may rep- resent air loads, inertia loads, or both, (See see. 4a.116.) 4aa4 Aerodynamic coefficients, Ci, Cus CP, ete, The coefficients hereinafter speci- fied are those of the “absolute” (nondimen- sional) system adopted as standard in the United States. The subscripts. and C used hereinafter refer respectively to directions normal to and parallel with the basic chord of the airfoil section. Other subscripts have the usual significance. When applied to an entire wing or surface, the coefficients rep- resent average values and shall be properly correlated with local conditions (load distri- bution) as required in section 4a.99. 4aa5 Standard atmosphere (standard air). Standard atmosphere refers to that variation of air conditions with altitude which has been adopted as standard in the United States. (See any aeronautics text book or handbook, or NACA Technical Re- port No. 218.) 4a46 Primary structure. ‘Those portions of the airplane the failure of which would seriously endanger the safety of the air- plane.CaM 40 AIRPLANE AIRWORTHINESS 5 Subpart C—Struetural Loading Conditions General Structural Requirements 4a61 Strength, The primary structure (00 see. 42.46) shall be capable of support- ing the ultimate loads (see see. 4a.13(f)) determined by the loading conditions and ul- timate factors of safety hereinafter speci- fied, the loads being properly distributed and applied, 44.62 Deformations, The primary struc- ture shall be capable of supporting without detrimental permanent deformations, for a period of at least one minute, the yield loads (see see. 42.43(g)) determined by the load- ing conditions and yield factors of safety hereinafter specified, the loads being prop- erly distributed and applied. Where no yleld factor of safety 1s specified a factor of 10 shall be assumed. In addition, tem- porary deformations which occur before the yield load is reached shall be of such a na- ture that their repeated occurrence will not weaken or damage the primary structure. 42.63 Stiffness, The primary structure shall be capable of supporting the limit loads (see sec, 4a.43(b)) determined by the load- ing conditions specified in this part without deflecting beyond whatever limits may be preseribed in this part or which may be deemed necessary by the Administrator for the case in question. 4a.04 Proof of strength and rigidity. No general requirements, but see Subpart D for specific requirements. 4a65 Materials, fabrication, protection, ete. No general requiroments, but see Sub- part E for specific requirements. Flight Loads 4a.72 General. The airworthiness rating of an airplane with respect to its strength under flight loads will be based on the sir speeds and accelerations (from maneuvering or gusts) which can safely be developed in combination. Far certain classes of air- planes the acceleration factors and gust velocities are arbitrarily specified herein- after and shall be used for those classes. ‘The air speeds which can safely be developed in combination with the specified accelera- tion factors and gusts shall be determined in aceordance with the procedure specified tn this part and shall serve as a basis for restricting the operation of the airplane in flight. (See see, 42.726.) Air Speeds 4a.13. Air speeds. (See see. 42.40 for def- initions.) The design air speeds shall be determined as follows: (a) V;, (see see. 42.40(c)). (b) Vy shall not be less than Vit Ky (Va-Vas except that it need not be greater than either ¥z+100 miles per hour or 15 Vay whichever is lower. K, is specified on Figure 4a-L Vy is defined in section 4a40(g). A special ruling may be obtained from the Ad- ministrator if the design gliding speed thus determined is greater than 1.33 Vz and ap- pears to be unnecessarily high for the type of airplane involved. (e) ¥; shall not be less than 2V defined in section 4a.40(e). (d) ¥, shall not be less than Vast Ky (Vi-Vords except that it need not be ereater than V:. K, is specified on Figure 4a-2. (e) (See sees. 4120, 4a.123, and 42.125 for exceptions for multiengine airplanes.) Var is Load Factors 4a74 General. The flight load factors specified in sections 4a.75—4a.99 shall repre- sent wing load factors. The net load factor, or acceleration factor, shall be obtained by proper consideration of balaneing loads act- ing on the airplane in the specific flight conditions. 42.75 Maneuvering load tactore. The limit maneuvering load factors specified in this part (see Fig. 4a-3) are derived largely from experience with conventional types of airplanes and shall be considered