3. 13 3. 14 and shall be completed by one engine. This engine shall be the same engine as is used in the operation test (see Section 3.13) and the vibration penalty run (see Section 3.11) if such a run is necessary. It need not, however, be the same engine as is used in any other tests. Variations of power and speed during the endurance test shall not exceed 3 percent of the specified values of speed and power. Operation Test. After the completion of the endurance test and the penalty vibration test (if required) the engine shall be subjected to 50 operating cycles. Each cycle shall consist of rapid acceleration from idling conditions to the take-off speed and power, followed by operation at the maximum-except-take-off speed and power and then rapid deceleration to idling conditions. Operation at idling, take-off and maximum-except-take-off power and speed shall be for a sufficiently long interval for all conditions to stabilize prior to changing to the next condition. This test shall be conducted with the same engine used for the endurance test and vibration penalty test (if required). During this test the engine shall not demonstrate any signs of malfunctioning or failure to accelerate rapidly. The condition of the engine at the completion of the endurance, vibration penalty (if required), and operation tests shall be such that it would be safe for continued operation. During these tests only minor repairs and servicing shall be permissible. However, major repair or replacement of parts may be resorted to if the parts in question are subjected to additional penalty tests. The extent of the penalty test shall be dependent upon the nature and extent of the repairs or replacements involved. Detonation Test. A test shall be conducted in which the engine is operated throughout the range from the lowest intended cruising speed to the take-off speed. During this test full throttle or the maximum brake mean effective pressure permissible (if full throttle cannot be used), the leanest specified fuel air ratio, the maximum engine, oil inlet and coolant outlet temperatures (whichever are applicable) and the highest permissible intake air temperatures shall be used in combination to determine whether the engine can function without detonation throughout its range and intended conditions of operation. 4.0 4.00 Part 4 PROPELLER AIRWORTHINESS DESIGN AND CONSTRUCTION. Propellers shall be designed and constructed to function reliably under all flight conditions when properly installed, operated, and maintained in an aircraft. Materials. Propellers shall be constructed of materials proved by experience or conclusive tests to be uniformly adequate in quality and strength and otherwise suitable for the parts in which they are used, 4. 01 4. 10 4. 100 4. 101 4. 102 Detail Design. Propellers shall incorporate only such details of design as have been proved by experience or conclusive tests to be reliable and otherwise satisfactory for safe operation. TESTS One propeller of each type shall satisfactorily complete the applicable tests specified in the following Sections without evidence of failure or malfunctioning. At the completion of the test the propeller shall be in a condition for continued safe operation without replacement of any parts. Only routine servicing or minor repairs shall be permissible during the test. If it is found necessary to replace any parts during the endurance or functional tests, an additional penalty test shall be conducted to substantiate the airworthiness of these parts. The duration of the penalty test shall be determined by the nature and extent of the replacement or change involved. Vibration Test. An investigation shall be conducted on propellers with metal blades to ascertain that the vibration stresses do not exceed values that are safe for continuous operation when the propeller is operated under all conditions of power and speed on an engine of the type with which its use is intended. Endurance Tests for Fixed Pitch Wood Propellers. Fixed pitch wood propellers shall be subjected to at least one of the following tests. (a) A 10-hour endurance block test on an internal combustion engine. During this test the propeller shall be operated at the proposed rated speed. (b) A 50-hour flight test. At least 5 hours of the flight test shall be conducted with the propeller operating at the proposed rated speed. During the remaining 45 hours the propeller shall be operated at not less than 90 percent of the proposed rated speed. These flight tests should be conducted in level flight or in climb. (c) A 50-hour endurance test at the power and speed for which certification is desired. A special propeller may be constructed for this test with a pitch which will permit operating it at the desired horsepower and RPM values. Endurance Tests for Propellers Other Than Fixed Pitch Wood Types. Such propellers shall be subjected to an endurance block test of 100 hours' duration on an aircraft engine of the same characteristics as the engine or engines with which the propeller is intended for use. At least 50 hours of this test shall be conducted at the proposed maximum-except-take-off speed and power ratings of the propeller. The remaining portion of the test shall be run under the conditions producing the most severe vibratory stresses in the propeller. If a rating in excess of the maximum-except-take-off power and speed ratings is desired for take-off purposes, 10 additional hours shall be conducted at the desired take-off ratings. Satisfactory completion of 10 4. 103 4. 104 4. 105 hours of operation at the take-off rating will be considered to establish the eligibility of the propeller for operation at this rating for not more than one minute of operation at a time, except that in the case of aircraft subjected to long-range operation the take-off rating may be used for not more than two minutes at a time. If eligibility for operation at the take-off rating for more than one or two minutes is desired, additional testing at these ratings shall be required. In lieu of the above 110-hour block test the airworthiness of such propellers may be substantiated by operation with an engine undergoing type test in accordance with the requirements of 3.12. The same ratings granted to the engine undergoing this type test may be granted to the propeller used in conjunction with such tests. Propellers whose blades can be turned to negative pitch angles shall be subjected to an additional test of 10 hours' duration at the maximum speed and power for which eligibility for operation at negative blade angles is desired. Functional Tests. Variable pitch propellers shall be subjected to the following functional tests. These tests shall be conducted while the propeller is driven by an electric motor, an aircraft engine mounted on a test stand, or in an aircraft in flight. These tests shall be conducted with the same propeller used in the endurance test. (a) Manually controllable propellers. Five hundred complete cycles of control from low speed operation to operation at the maximum take-off speed and power, then returning to the low speed condition. If an engine is used to drive the propeller during this test, the power shall not be reduced during any portion of the cycle, below the maximum power that the engine can safely withstand at each speed. (b) Automatically controllable propellers. Fifteen hundred complete cycles of control by means of the automatic control mechanism, under the conditions described in (a) above. (c) Feathering propellers. Fifty cycles of feathering operation shall be conducted to substantiate the airworthiness of this feature. Overspeed Tests. Propellers of completely new design or of unconventional design shall be subjected to one hour of operation at a speed sufficient to produce centrifugal loads equal to double the centrifugal load existing during operation at the maximum-except-take-off speed rating unless the ability of the propeller to withstand this load can be demonstrated by static pull tests or in some other suitable manner. The blade angle of the propeller may be adjusted so that the power required to operate the propeller at the test speed does not exceed the maximum-except-take-off rated power. Miscellaneous Tests. Water spray, low temperature or other tests shall be conducted when deemed necessary to substantiate the airworthiness of the propeller due to unconventional features of design, material, construction or other reasons. Part 5 5.0 5. 1 5. 11 5. 111 5. 1111 5. 1112 5. 1113 5.2 5.20 EQUIPMENT AIRWORTHINESS REQUIREMENTS GENERAL At least the following items of equipment shall be approved by the authorities of the State whose nationality the aircraft possesses. Items of equipment not specifically mentioned hereinafter but which may affect the safety of operation of the aircraft shall be investigated by the said authorities to determine that they are constructed of suitable materials, and are free from hazard in themselves and their method of operation, and adequately serve the purpose intended. WHEELS Landing Gear Wheels (Main and Nose.) These wheels shall be approved for a maximum static load which is determined from the strength of the wheel. Tail wheels need not receive specific approval. Tests. The strength of a landing gear wheel shall be substantiated by a radial, side, and combined radial and pressure test. Radial Test Load. The required radial test load shall be equal to (P) × (n) X (1.5) × (1.15) where P= the maximum static load in pounds (kg) for which approval is requested, 9000 n = 2.80 + 2P + 4000, except that it need not be greater Side Test Load. The required side test load is equal to (0.35)(the radial test load). Combined Radial and Pressure Test. The wheel shall withstand without failure the radial load specified in Section 5.1111 when the tire is inflated to a hydraulic pressure equal to 2 times the inflation pressure established. If the tire is available in more than one rating because of additional plies, the tire having the highest rating for the particular size shall be used. The wheel shall show no signs of undue strain or distortion under this combined load. BRAKES Testing of Brakes for Certification (a) A wheel-brake combination shall demonstrate satisfactory performance during 100 tests simulating the stopping of an airplane at an average deceleration of at least 10 feet 5.21 (3.05 m.) per second per second, from a speed chosen by the applicant. The kinetic energy absorbed per stop shall be computed and the wheel-brake combination shall be certificated for a kinetic energy absorption not in excess of the amount so determined. (b) To be eligible for use on airplanes certificated in accordance with the transport category requirements of Part 2, a wheel-brake combination shall further demonstrate satisfactory performance during three tests identical with those specified in paragraph (a) except that the speed shall be increased to obtain a kinetic energy absorption 125 percent of that determined under that paragraph. Adaptation of Brakes to Airplanes-Other Than Transport -NUA Category. Where approved wheel-brake combinations are required by the State whose nationality the aircraft possesses for other than transport category airplanes, the summation of the kinetic energy ratings of the brakes used in the main landing gear shall be equal to: 5. 21 -T 5. 22 5.23 5. 24 5.25 K. E.=.0334W V2, for nose wheel type of airplanes and K. E.=.0224 W V2, for tail wheel type of airplanes where K. E.-kinetic energy in foot-pounds (kgm.) W the approved landing weight, lbs. (kg.) V. the power-off stalling speed of the airplane in miles per hour (km/hr.) at sea level in standard air at maximum landing weight. The wheel-brake combinations shall have been tested at a speed between 80 percent and 100 percent of V ̧. Adaptation of Brakes to Airplanes Transport Category. The requirements of Section 5.1 are applicable except that the summation of the kinetic energy ratings of the brakes used in the main landing gear shall be at least equal to K. E.=.0334 W V2, (.00393 W V,2 metric) for either a tail wheel or nose wheel type of airplane. 8 Design. Brakes shall be free from any undue tendency to lock or jam, and shall be suitably shielded from water, dirt, and oil. Static Torque. The maximum available static torque in reverse shall be at least 40 percent of the forward static torque when both are measured at the same applied pedal force. Adjustment. When necessary to insure satisfactory performance, brake mechanism shall be equipped with suitable adjustment devices to compensate for disk or lining wear, heat, and other normal service effects. Strength. The brake and all of its attachments to the wheel shall satisfactorily pass a test at an ultimate torque load of 1.6 WR/B, where R is the rolling radius of the tire and B is the number of brakes. In addition, a static test of the brake and wheel shall demonstrate that the assembly is |