(3) Wind direction and wind velocity should be recorded adjacent to the runway at a height of 6 feet. [Supp. 24, 19 F.R. 4454, July 20, 1954, as amended by Supp. 34, 22 F.R. 6963, Aug. 29, 1957] § 4b.123-3 Reverse thrust used in landing distance-landplanes (FAA policies which apply to § 4b.123 (c)). The policies outlined in § 4b.402-1(1) will apply. [Supp. 25, 20 F. R. 2277, Apr. 8, 1955] § 4b.123-4 Procedure in determination of landing distance with an antiskid device installed (FAA policies which apply to § 4b.123). The policies outlined in § 4b.337-4 will apply. [Supp. 28, 21 F. R. 2558, Apr. 19, 1956] § 4b.124 Seaplanes or float planes. The landing distance referred to in § 4b.122 shall be determined on smooth water. § 4b.130 CONTROLLABILITY Controllability; general. (a) The airplane shall be safely controllable and maneuverable during takeoff, climb level flight, descent, and landing. (b) It shall be possible to make a smooth transition from one flight condition to another, including turns and slips, without requiring an exceptional degree of skill, alertness, or strength on the part of the pilot and without danger of exceeding the limit load factor under all conditions of operation probable for the type, including those conditions normally encountered in the event of sudden failure of any engine. § 4b. 130-1 Procedure for demonstrating controllability qualities (FAA policies which apply to § 4b.130). The general controllability and maneuverability qualities of the airplane should be observed and noted throughout the flight test program. The amount of force required to be exerted on the controls in conducting such maneuvers specified in § 4b.130 should also be noted. [Supp. 24, 19 F. R. 4454, July 20, 1954] § 4b.131 Longitudinal control. (a) It shall be possible at all speeds between the trim speed prescribed in § 4b.112(c) (1) and Vs, to pitch the nose downward so that a prompt recovery to this selected trim speed can be made with the following combination of airplane configurations: (1) The airplane trimmed at the trim speed prescribed in § 4b.112(c) (1), (2) The landing gear extended, (3) The wing flaps in a retracted, and in an extended position, (4) Power off, and maximum continuous power on all engines. (b) During each of the following controllability demonstrations a change in the trim control, or the exertion of more control force than can be readily applied with one hand for a short period, shall not be required. Each maneuver shall be performed with the landing gear extended. (1) With power off, flaps retracted, and the airplane trimmed at 1.4 V11, the flaps shall be extended as rapidly as possible while maintaining the air speed approximately 40 percent above the stalling speed prevailing at any instant throughout the maneuver. (2) The maneuver of subparagraph (1) of this paragraph shall be repeated, except that it shall be started with flaps extended and the airplane trimmed at 1.4 Vs,, after which the flaps shall be retracted as rapidly as possible. (3) The maneuver of subparagraph (2) of this paragraph shall be repeated, except that take-off power shall be used. (4) With power off, flaps retracted, and the airplane trimmed at 1.4 V11. take-off power shall be applied quickly while maintaining the same air speed. (5) The maneuver of subparagraph (4) of this paragraph shall be repeated, except that the flaps shall be extended. (6) With power off, flaps extended, and the airplane trimmed at 1.4 V11, air speeds within the range of 1.1 V11 to 1.7 Vs, or to VFE. whichever of the two is the lesser, shall be obtained and maintained. (c) It shall be possible without the use of exceptional piloting skill to prevent loss of altitude when wing flap retraction from any position is initiated during steady straight level flight at a speed equal to 1.1 V11 with simultaneous application of not more than maximum continuous power, with the landing gear extended, and with the airplane weight equal to the maximum sea level landing weight. (See also § 4b.323.) [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F.R. 1089, Feb. 5, 1952; Amdt. 4b-11, 24 F.R. 7068, Sept. 1, 1959] § 4b.131-1 Procedure for demonstrating longitudinal control (FAA policies which apply to § 4b.131). The flight tests specified in paragraphs (a) through (h) of this section should be made in demonstrating compliance with § 4b.131. These tests may be conducted at an optional altitude (see § 4b.100-3 (c)). Where applicable, the following conditions should be maintained on the engines: propellers in low pitch; throttles-closed except as noted; cowl flaps appropriate for the flight condition. (a) Longitudinal control recovery § 4b.131(a). The test specified by this requirement should be demonstrated with power off and also with maximum continuous power. (1) Configuration. This test should be conducted in the configuration that follows: (i) Maximum take-off weight, flaps and landing gear retracted, C. G. position-most aft. (11) Maximum landing weight, flaps extended in the maximum landing position; landing gear extended, C. G. position-most aft. (The flap extended portion of this test may be combined with tests under paragraph (g) of this section.) (2) Test procedure and required data. The airplane should be trimmed at the speed prescribed in § 4b.112(c) (1); the nose should be pitched downward starting from any speed between that prescribed in § 4b.112 (c) (1), and V11. The rate of increase in airspeed should be satisfactory for prompt acceleration to the trim speed prescribed in § 4b.112 (c) (1). The following data should be recorded: Weight. C.G. position. Wing flap position. Engines, r.p.m. and manifold pressure. Ambient air temperature. Trim speed. Lowest speed from which pitch is satisfactory. Altitude lost to regain trim speed. (b) Longitudinal control, flap extension, § 4b.131 (b) (1)—(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward and most aft. Landing gear-Extended. (2) Test procedure and required data. The airplane should be trimmed at a speed of 1.4 V11; the flaps should be extended to the maximum landing position as rapidly as possible. During this maneuver, it should be possible to control the airplane with one hand for a reasonable time without the necessity of changing the trim control. The following data should be recorded: Weight. C. G. position. Wing flap position. Landing gear position. Engines, rpm and manifold pressure. Pressure altitude. Ambient air temperature. Trim speed at 1.4 V ̧ ̧· (c) Longitudinal control, flap retraction § 4b.131 (b) (2)—(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward and most aft. (2) Test procedures and required data. The airplane should be trimmed at a speed of 1.4 V11; the flaps should be retracted as rapidly as possible. During this maneuver, it should be possible to control the airplane with one hand for a reasonable time without the necessity of changing the trim control. The same data as are specified in paragraph (b) (2) of this section should be recorded. (d) Longitudinal control, flap retraction § 4b.131 (b) (3). The maneuver shown in paragraph (c) (2) of this section should be repeated with take-off power on all engines. (e) Longitudinal control, power application, § 4b.131 (b) (4)—(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward and most aft. (2) Test procedure and required data. The airplane should be trimmed at a speed of 1.4 V11; take-off power should be applied quickly without changing the air speed. During this maneuver, it should be possible to control the airplane with one hand for a reasonable time without the necessity of changing the trim control. The same data as are specified in paragraph (b) (2) of this section should be recorded. (f) Longitudinal control, power application, § 4.131 (b) (5)—(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward and most aft. Wing flaps-Maximum landing position. Landing gear-Extended. Engines Power off. (2) Test procedure and required data. The airplane should be trimmed at a speed of 1.4 V11; take-off power should be applied quickly without changing the air speed. During this maneuver, it should be possible to control the airplane with one hand for a reasonable time without the necessity of changing the trim control. The same data as are specified in paragraph (b) (2) of this section should be recorded. (g) Longitudinal control, air speed variation, § 4b.131 (b) (6)—(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward. Wing flaps-Maximum landing position. (2) Test procedure and required data. The airplane should be trimmed at a speed of 1.4 V3, and it should be possible to control the airplane with one hand for a reasonable time without the necessity of changing the trim control when (i) The speed is reduced to 1.1 Vs1, (ii) The speed is increased to 1.7 V11 or to the placard flap speed. In addition to the data specified in (b) (2) of this section, the recorded data should also include the air speeds at 1.1 Vs, and 1.7 Vs, (or VFE whichever is the lesser). (h) Longitudinal control, flap retraction and power application, § 4b.131 (c)-(1) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most forward and most aft. (2) Test procedure and required data. The airplane should be maintained in a steady horizontal flight at a speed of 1.1 V11; the flaps should be retracted from the maximum landing position with simultaneous application of not more than maximum continuous power. During this maneuver, it should be possible to prevent a loss of altitude without the use of exceptional piloting skill. The following data should be recorded: Weight. C. G. position. Wing flap position. Landing gear position. Engines, rpm and manifold pressure before and after tests. Pressure altitude. Ambient air temperature. [Supp. 24, 19 F.R. 4454, July 20, 1954, as amended by Supp. 42, 24 F.R. 7072, Sept. 1, 1959] § 4b.132 Directional and lateral control. (a) Directional control; general. It shall be possible, while holding the wings approximately level, to execute reasonably sudden changes in heading in either direction without encountering dangerous characteristics. Heading changes up to 15° shall be demonstrated, except that the heading change at which the rudder pedal force is 180 pounds need not be exceeded. The control shall be demonstrated at a speed equal to 1.4 V11, under the following conditions: (1) The critical engine inoperative and its propeller in the minimum drag position, (2) Power required for level flight at 1.4 Vs,, but not greater than maximum continuous power, (3) Most unfavorable center of gravity position, (4) Landing gear retracted, (5) Wing flaps in the approach position, (6) Maximum landing weight. (b) Directional control; four or more engines. Airplanes with four or more engines shall comply with paragraph (a) of this section, except that: (1) The two critical engines shall be inoperative, their propellers in the minimum drag position, (2) The center of gravity shall be in the most forward position, (3) The wing flaps shall be in the most favorable climb position. It shall (c) Lateral control; general. be possible to execute 20° banked turns with and against the inoperative engine from steady flight at a speed equal to 1.4 V11 with: (1) The critical engine inoperative and its propeller in the minimum drag position, (2) Maximum continuous power on the operating engines, (3) Most unfavorable center of gravity position, (4) Landing gear retracted and extended, (5) Wing flaps in the most favorable climb position, (6) Maximum take-off weight. (d) Lateral control; four or more engines. It shall be possible to execute 20° banked turns with and against the inoperative engines from steady flight at a speed equal to 1.4 Vs, with maximum continuous power and with the airplane in the configuration prescribed by paragraph (b) of this section. (e) Lateral control; all engines operating. Roll response shall be rapid and of sufficient magnitude to perform normal maneuvers, such as recovery from upsets produced by gusts and the initiation of evasive maneuvers. In sideslips up to sideslip angles which might be required in normal operation, sufficient excess lateral control shall remain to perform a limited amount of maneuvering and to correct for gusts. Lateral control shall be sufficient at all speeds up to VNE to provide a peak roll rate necessary for safety without requiring excessive control forces or excessive control travel. [15 F.R. 3543, June 8, 1950, as amended, 15 F.R. 4171, June 29, 1950; Amdt. 4b-8, 23 F.R. 2590, Apr. 19, 1958] (a) Appropriate instrumentation. When conducting directional and lateral control tests, the airplane should contain appropriate instrumentation in order to obtain the following data: (1) Section 4b.132 (a) and (b). Instrumentation to indicate airplane heading angle and rudder force. (2) Section 4b.132 (c) and (d). Instrumentation to measure bank angle. (b) General test program-(1) Directional control; general, § 4b.132 (a)—(i) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. C. G. position-Most aft. Wing flaps-Approach position. Cowl flaps-Appropriate for flight condition. maintain Operating engine (s)-Power to level flight at 1.4 Vs, but nɔt more than maximum continuous power. Critical inoperative engine-Propeller feathered on engine most critical for controllability. (ii) Test procedure and required data. The airplane should be trimmed as indicated above at any optional altitude (see § 4b.100-3 (c)). Reasonable sudden changes in heading to the left and right, using ailerons to maintain approximate level flight, should be made demonstrating a change of 15°, or the angle at which a dangerous condition is encountered, or at which 180 lbs. rudder force is required. The airplane should be satisfactorily controllable during this maneuver. The following data should be recorded: Weight. C. G. position. Wing flap position. Landing gear position. Operating engine(s), rpm and manifold pressure. Position of critical inoperative engine and its propeller. Pressure altitude. Rudder force at maximum deflection. (2) Directional control; four or more engines, § 4b.132 (b)-(i) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum landing. Landing gear-Retracted. Operating engines-Power required for level flight at 1.4 V1, but not more than maximum continuous power. Critical inoperative engines-Propellers feathered on outboard engine most critical for controllability and on adjacent engine. (ii) Test procedure and required data. The test procedure shown in subparagraph (1) (ii) of this paragraph should be repeated with two critical engines inoperative. In addition to the data specified in subparagraph (1) (ii) of this paragraph, the position of the critical inoperative engines and the propeller configuration should also be recorded. (3) Lateral control; general, § 4b.132 (c)-(i) Configuration. This test should be conducted in the configuration that follows: Weight-Maximum take-off. Landing gear-Retracted and extended. Operating engine (s)-Maximum continuous power. Critical inoperative engine-Throttle closed on engine most critical for controllability, propeller feathered. (ii) Test procedure and required data. Banked turns of 20° should be demonstrated with and against the inoperative engine from a steady climb at 1.4 V11. The following data should be recorded: Weight. C. G. position. Wing flap position. Landing gear position. Engine(s), rpm and manifold pressure. Position of critical inoperative engine and its propeller. Pressure altitude. Ambient air temperature. Trim speed at 1.4 V11 Rudder force at maximum deflection. (4) Lateral control; four or more engines, 4b.132 (d)—(i) Configuration This test should be conducted in the configuration that follows: Weight-Maximum landing. Operating engines-Power required for level strated with and against inoperative engines from steady flight at 1.4 V11. The same data as are specified in subparagraph (3) (ii) of this paragraph should be recorded. [Supp. 24, 19 F. R. 4455, July 20, 1954] § 4b.133 Minimum control speed, c. (a) A minimum speed shall be determined under the conditions specified in this paragraph, so that when the critical engine is suddenly made inoperative at that speed it shall be possible to recover control of the airplane, with the engine still inoperative, and maintain it in straight flight at that speed, either with zero yaw or, at the option of the applicant, with an angle of bank not to excess of 5°. Such speed shall not exceed 1.2 with: (1) Take-off or maximum available power on all engines, (2) Rearmost center of gravity, (3) Flaps in take-off position, (4) Landing gear retracted, (5) Cowl flaps in the position normally used during take-off, (6) Maximum sea level take-off weight, or such lesser weight as may be necessary to demonstrate VMC, (7) The airplane trimmed for take-off, (8) The propeller of the inoperative engine windmilling, except that a different position of the propeller shall be acceptable if the specific design of the propeller control makes it more logical to assume the different position, (9) The airplane airborne and the ground effect negligible. (b) In demonstrating the minimum speed of paragraph (a) of this section, the rudder force required to maintain control shall not exceed 180 pounds, and it shall not be necessary to throttle the remaining engines. (c) During recovery of the maneuver of paragraph (a) of this section the airplane shall not assume any dangerous attitude, nor shall it require exceptional skill, strength, or alertness on the part of the pilot to prevent a change of heading in excess of 20° before recovery is complete. [15 F. R. 3543, June 8, 1950, as amended by Amdt. 4b-6, 17 F. R. 1089, Feb. 5, 1952] NOTE: Interpretation No. 1 (17 F. R. 2112, Mar. 12, 1952), adopted by the Civil Aeronautics Board, Mar. 7, 1952, provides as follows: |