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Vs, is being used as a factor to determine a required performance.

(c) These speeds shall be determined by flight tests using the procedure outlined in § 3.120. § 3.82-1 “Zero thrust" (FAA interpreta

tions which apply to $ 3.82). As used in $ 3.82(a)(1) and (b) (1) the term “zero thrust" contained in the phrase "engines idling, throttles closed (or not more than suficient power for zero thrust)" is interpreted to permit "zero thrust at a speed not greater than 110 percent of the stalling speed." [Supp. 1, 12 F. R. 3434, May 28, 1947, as amended by Amdt. 1, 14 F. R. 36, Jan. 5, 1949] $ 3.83 Stalling speed.

Vs, at maximum weight shall not exceed 70 miles per hour for (1) singleengine airplanes and (2) multiengine airplanes which do not have the rate of climb with critical engine inoperative specified in $ 3.85(b).

TAKE-OFF $ 3.84 Take-off.

(a) The distance required to take off and climb over a 50-foot obstacle shall be determined under the following conditions:

(1) Most unfavorable combination of weight and center of gravity location,

(2) Engines operating within the approved limitations,

(3) Cowl flaps in the position normally used for take-off.

(b) Upon obtaining a height of 50 feet above the level take-off surface, the airplane shall have attained a speed of not less than 1.3 Vs, unless a lower speed of not less than Vi plus 5 can be shown to be safe under all conditions, including turbulence and complete engine failure.

(c) The distance so obtained, the type of surface from which made, and the pertinent information with respect to the cowl flap position, the use of flight-path control devices and landing gear retraction system shall be entered in the Airplane Flight Manual. The take-off shall be made in such a manner that its reproduction shall not require an exceptional degree of skill on the part of the pilot or exceptionally favorable conditions. $ 3.84–1 Take-off performance (FAA

policies which apply to g 3.84). To meet the requirements of $ 3.84 pertaining to certification of take-off

performance and to provide the Airplane Flight Manual performance data required in $ 3.780(a) (3) and (4), the following procedure may be used during official type tests:

(a) The ground and climb distances may be determined separately and the corrected data pieced together (as is now dune in the transport category). Thus, for the simplest procedure, the airplane would be accelerated on (or near) the ground with gear extended to a speed not less than 1.3Vs, and a climb segment to the 50-foot height point with gear extended would be determined by saw-tooth climb data. If it is desired to assume retraction of the landing gear at an earlier point, such point should be assumed to occur not earlier than that which would be used in normal take-offs. The acceleration to 1.3Vs, should then be measured as above, with gear retraction being initiated at the selected speed. If gear retraction is completed before reaching 1.3Vsy, only one climb segment, with gear retracted, need be determined. If retraction is not completed during acceleration to 1.3Vs, two climb segments should be determined; one with gear ext for the time period necessary to complete retraction; the second with gear retracted. The acceleration segment should be determined photographically, and a minimum of three trials should be made up to speeds equal to or greater than 1.3Vsz.

NOTE: (FAA camera equipment may be obtained on a loan basis).

(b) Based upon the FAA's experience to date, the test method outlined in paragraph (a) of this section has given the desired accuracy of results. It also provides suitable means for showing the approximate calculated effect of temperature and altitude upon climb (up to 7,000 feet).

NOTE: It is permissible for other methods to be used in accomplishing these tests, pro. viding that any method used is one which the average pilot may be reasonably expected to duplicate without use of unusual skill or experience, and one which produces equivalent accuracy. The operating procedure which must be followed to achieve the measured performance should in all cases be described in the Airplane Flight Manual.

(c) The take-off and climb requirements of $$ 3.84 and 3.85 were written to assure the airplane's ability to clear obstacles in the vicinity of the airport. Consequently, the wing flap used for the

CLIMB

airborne portion of the takeoff to the 50-foot height should not exceed that used for the “normal climb condition" of $ 3.85 (a). However, if the applicant so desires, he may enter additional take-off data in the Airplane Flight Manual in which the flap setting specified in g 3.84 or $ 3.85 (a) has been exceeded, provided the portion of the flight path beyond the 50-foot point which will cover the transition to normal climb configuration of $ 3.85 (a), is also included. (Supp. 10, 16 F. R. 3283, Apr. 14, 1951) $ 3.84–2 Measurement of seaplane take

off distances (FAA interpretations

which apply to g 3.84(a)). The standard starting point for the measurement of seaplane take-off distances may be assumed to be the point at which the seaplane has attained an initial speed of three miles per hour during take-off. [Supp. 10, 16 F. R. 3283, Apr. 14, 1951] $ 3.84—3 Take-off speed (FAA interpre

tations which apply to $ 3.84(b)). 1.3XV., or V:+5 speed should be used for take-off even if throttling back is necessary to prevent exceeding r. p. m. limits. [Supp. 10, 16 F. R. 3283, Apr. 14, 1951) $ 3.84a Take-off requirements; air

planes of 6,000 lbs. or less. Airplanes having a maximum certificated take-off weight of 6,000 lbs. or less shall comply with the provisions of this section.

(a) The elevator control for tail wheel type airplanes shall be sufficient to maintain at a speed equal to 0.8 Vs, an airplane attitude which will permit holding the airplane on the runway until a safe take-off speed is attained.

(b) The elevator control for nose wheel type airplanes shall be sufficient to · raise the nose wheel clear of the takeoff surface at a speed equal to 0.85 Voz

(c) The characteristics prescribed in paragraphs (a) and (b) of this section shall be demonstrated with:

(1) Take-off power,
(2) Most unfavorable weight,
(3) Most unfavorable c. g. position.

(d) It shall be demonstrated that the airplane will take off safely without requiring an exceptional degree of piloting skill.

8 3.85 Climb.

(a) Normal climb condition. The steady rate of climb at sea level shall be at least 300 feet per minute, and the steady angle of climb at least 1:12 for landplanes or 1:15 for seaplanes with:

(1) Not more than maximum continuous power on all engines,

(2) Landing gear fully retracted,
(3) Wing flaps in take-off position,

(4) Cowl flaps in the position used in cooling tests specified in $ $ 3.581-3.596.

(b) Climb with inoperative engine. All multiengine airplanes having a stalling speed Vs, greater than 70 miles per hour or a maximum weight greater than 6,000 pounds shall have a steady rate of climb of at least 0.02 Vs' in feet per minute at an altitude of 5,000 feet with the critical engine inoperative and:

(1) The remaining engines operating at not more than maximum continuous power,

(2) The inoperative propeller in the minimum drag position,

(3) Landing gear retracted,

(4) Wing flaps in the most favorable position,

(5) Cowl flaps in the position used in cooling tests specified in 88 3.581–3.596.

(c) Balked landing conditions. The steady angle of climb at sea level shall be at least 1:30 with:

(1) Take-off power on all engines,
(2) Landing gear extended,

(3) Wing flaps in landing position. If rapid retraction is possible with safety without loss of altitude and without requiring sudden changes of angle of attack or exceptional skill on the part of the pilot, wing flaps may be retracted. $ 3.85–1 Rate of climb (FAA policies

which apply to $ 3.85). To meet the requirements of $ 3.85 it is necessary that a suitable method be employed for the purpose of determining the rates of climb. The Administrator will accept the following procedure for this purpose:

This method of obtaining rates of climb is through the derivation of a polar curve obtained from a series of sawtooth climbs at various speeds. When saw-tooth climbs are employed, a minimum of five different speeds is required.

However, demonstration climbs to prove the article meets the minimum climb requirement may be made at one given air speed. In such cases, the minimum number of climbs at one air speed shall be not less than three. This may not be interpreted to mean the best three of a number of climbs. In the event additional climbs are made the average of the total shall be the value to be accepted. It shall be permissible, however, to discard any climbs which are obviously in error due to such factors as turbulent air. (Supp. 1, 12 F. R. 3434, May 28, 1947, as amended by Amdt. 1, 14 F. R. 36, Jan. 5, 1949) $ 3.85-2 “Normal climb” and “cooling

test procedure for single-engine airplanes” (FAA interpretations which

apply to $ 3.85). In connection with any application to have an aircraft certified for airworthiness under a combination of the requirements of this part and Part 4a of this subchapter as authorized by the provisions of $ 3.2, the items of “normal climb" ($ 3.85(a)) and “cooling test procedure for single-engine airplanes” ($ 3.586), shall be construed by the Administrator as “related items." [Supp. 1, 12 F. R. 3435, May 28, 1947, as amended by Amdt. 1, 14 F. R. 36, Jan. 5, 1949) $ 3.85–3 “Rapid retraction” (FAA in

terpretations which apply to $ 3.85). The Administrator will consider retraction of flaps in 2 seconds or less as compliance with the factor of “rapid retraction” as that phrase is used in § 3.85 (c). (Supp. 1, 12 F. R. 3435, May 28, 1947, as amended by Amdt. 1, 14 F. R. 36, Jan. 5, 1949] $ 3.854 Weight for items of perform

ance and flight characteristics (FAA interpretations which apply to

$ 3.85). For multiengine airplanes in which the design landing weight (§ 3.242) is less than the maximum weight ($ 3.74) for which certification is desired, the weight for items of performance and flight characteristics shall be construed by the Administrator as the maximum weight defined in $ 3.74. Such items of performance and flight characteristics shall consist of balked landing (climb) conditions (83.74), landing over 50-foot obstacles ($ 3.86), and all flight charac

teristics tests in the landing configuration. The design weight covered in $ 3.242 is intended for use for structural design purposes only. (Supp. 1, 12 F. R. 3436, May 28, 1947, 48 amended by Amdt. 1, 14 F. R. 36, Jan 5, 1949) 8 3.85-5 Low-pitch propeller setting in

normal climb position (FAA inter.

pretations which apply to § 3.85(a)). (a) In the event an airplane has:

(1) An engine for which the take-off and maximum continuous power ratings are identical, and

(2) A fixed-pitch, two-position or similar type propeller, then the regulations provide that the best rate of climb speed specified in § 3.85 (a) for normal climb should be determined with the low-pitch propeller setting which would restrain the engine to an r. p. m. at full throttle not exceeding its permissible take-off r. p. m. (see $ 3.419 (a)).

(b) A relaxation of the propeller pitch setting requirement stipulated by $ 3.419 (a) may be granted, however, for an airplane falling into the foregoing classification, when it shows a marginal item of performance as, for example, when it can meet the rate of climb requirement of $ 3.85 (a) for normal climb, but may have difficulty in meeting the angle of climb requirements of $ 3.85 (a) for normal climb and/or $ 3.85 (c) for balked landing. In this case, it will be permis. sible to use a lower propeller pitch setting than specified in g 3.419 (a), in order to obtain rated engine r. p. m. at the best angle of climb speed: Provided, Acceptable engine cooling can be demonstrated at the lower speed associated with the best angle of climb. In employ. ing this procedure, consideration should also be given to the following:

(1) That the best angle of climb speed for the balked landing condition may be considerably lower than the best angle of climb speed for the normal climb condition.

(2) That as a result of subparagraph (1) of this paragraph, the engine would normally have to be part throttled to avoid exceeding rated r. p. m. at the higher speeds, and would therefore develop less than rated power for show. ing compliance with the normal climb. and take-off requirements of $$ 3.85 (8) and 3.84, respectively. (Supp. 10, 16 F. R. 3283. Apr. 14, 1951)

$ 3.85a Climb requirements; airplanes

of 6,000 lbs. or less. Airplanes having a maximum certificated take-off weight of 6,000 lbs. or less shall comply with the requirements of this section.

(a) Climb; take-of climb condition. The steady rate of climb at sea level shall not be less than 10 Vs, or 300 feet per minute, whichever is the greater, with:

(1) Take-off power,
(2) Landing gear extended,
(3) Wing flaps in take-off position,

(4) Cowl flaps in the position used in cooling tests specified in $$ 3.581 through 3.596.

(b) Climb with inoperative engine. All multiengine airplanes having a stalling speed Vso greater than 70 miles per bour shall have a steady rate of climb of at least 0.02 Vs' in feet per minute at an Altitude of 5,000 feet with the critical engine inoperative and:

(1) The remaining engines operating at not more than maximum continuous power,

(2) The inoperative propeller in the minimum drag position,

(3) Landing gear retracted,

(4) Wing flaps in the most favorable position,

(5) Cowl flaps in the position used in rooling tests specified in $$ 3.581 through 3.596.

(c) Climb; balked landing condi. ions. The steady rate of climb at sea evel shall not be less than 5 Vs, or 200 'eet per minute, whichever is the greater, vith:

(1) Take-off power,
(2) Landing gear extended,

(3) Wing flaps in the landing position. f rapid retraction is possible with safety, rithout loss of altitude and without reuiring sudden changes of angle of atack or exceptional skill on the part of he pilot, wing flaps may be retracted.

LANDING 3.86 Landing.

(a) The horizontal distance required , land and to come to a complete stop to a speed of approximately 3 miles per our for seaplanes or float planes) from

point at a height of 50 feet above the unding surface shall be determined as llows:

(1) Immediately prior to reaching the 50-foot altitude, a steady gliding approach shall have been maintained, with a true indicated air speed of at least 1.5V.1.

(2) The landing shall be made in such a manner that there is no excessive vertical acceleration, no tendency to bounce, nose over, ground loop, porpoise, or water loop, and in such a manner that its reproduction shall not require any exceptional degree of skill on the part of the pilot or exceptionally favorable conditions.

(b) The distance so obtained, the type of landing surface on which made and the pertinent information with respect to cowl flap position, and the use of flight path control devices shall be entered in the Airplane Flight Manual. (21 F.R. 3339, May 22, 1956, as amended by Amdt. 3-5, 24 F.R. 7066, Sept. 1, 1969] & 3.86–1 Landing distances (FAA poli

cies which apply to $ 3.86). The Administrator will not approve the use of landing distances obtainable with reverse-thrust propellers in establishing landing field lengths until such time as suficient experience with their use is available for proper consideration of all related factors involved in the establishment of adequate airport lengths for routine landings. [Supp. 1, 12 F. R. 8487, May 28, 1947, as amended by Amdt. 1, 14 F. R. 36, Jan. 6, 1949) $ 3.86–2 Use of

equipment (FAA policies which apply to $ 3.86). The landing distance should be determined photographically. FAA camera equipment is available on a loan basis. [Supp. 10, 16 F. R. 3284, Apr. 14, 1951) $ 3.87 Landing requirements; airplanes

of 6,000 lbs. or less. For an airplane having a maximum certificated take-off weight of 6,000 lbs. or less it shall be demonstrated that the airplane can be safely landed and brought to a stop without requiring an exceptional degree of piloting skill, and without excessive vertical acceleration, tendency to bounce, nose over, ground loop, porpoise, or water loop.

FLIGHT CHARACTERISTICS $ 3.105 Requirements.

The airplane shall meet the requirements set forth in $ $ 3.106 to 3.124 at all normally expected operating altitudes

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under all critical loading conditions within the range of center of gravity and, except as otherwise specified, at the maximum weight for which certification is sought.

CONTROLLABILITY $ 3.106 General.

The airplane shall be satisfactorily controllable and maneuverable during take-off, climb, level flight, dive, and landing with or without power. 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 for multiengine airplanes those conditions normally encountered in the event of sudden failure of any engine. Compliance with "strength of pilots" limits need not be demonstrated by quantitative tests unless the Administrator finds the condition to be marginal. In the latter case they shall not exceed maximum values found by the Administrator to be appropriate for the type but in no case shall they exceed the following limits:

(1) Maximum continuous power on all engines, the airplane trimmed at Vs.

(2) Power-off and the airplane trimmed at 1.5 Vs, or at the minimum speed, whichever is higher.

(3) (i) Wing flaps and landing gear extended and

(ii) Wing flaps and landing gear retracted.

(b) During each of the controllability demonstrations outlined below it shall not require 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. Each maneuver shall be performed with the landing gear extended.

(1) With power off, flaps retracted, and the airplane trimmed as prescribed in paragraph (a) (2) of this section, the flaps shall be extended as rapidly as possible while maintaining the air speed at approximately 40 percent above the instantaneous value of the stalling speed.

(2) Same as subparagraph (1) of this paragraph, except the flaps shall be initially extended and the airplane trimmed as prescribed in paragraph (a) (2) of this section, then the flaps shall be retracted as rapidly as possible.

(3) Same as subparagraph (2) of this paragraph, except maximum continuous power shall be used.

(4) With power off, the flaps retracted, and the airplane trimmed as prescribed in paragraph (a) (2) of this section, take-off power shall be applied quickly while the same air speed is maintained.

(5) Same as subparagraph (4) of this paragraph, except with the flaps extended.

(6) With power off, flaps extended, and the airplane trimmed as prescribed in paragraph (a) (2) of this section, air speeds within the range of 1.1 Vs, to 1.7 V8, or V1, whichever is the lesser, shall be obtained and maintained.

(c) It shall be possible without the use of exceptional piloting skill to maintain essentially level flight when flap retraction from any position is initiated during steady horizontal flight at 1.1 V with simultaneous application of not more than maximum continuous power.

(d) It shall be possible to maintain a speed of not more than 1.5 Vs, with a pilot control force of not more than 10

[blocks in formation]

1 Applied to rim. $ 3.107-U Approved acrobatic maneu

vers. It shall be demonstrated that the approved acrobatic maneuvers can be performed safely. Safe entry speeds shall be determined for these maneuvers. $ 3.108–A Acrobatic maneuvers.

It shall be demonstrated that acrobatic maneuvers can be performed readily and safely. Safe entry speeds shall be determined for these maneuvers. $ 3.109 Longitudinal control.

The airplane shall be demonstrated to comply with the following requirements:

(a) It shall be possible at all speeds below V: to pitch the nose downward so that the rate of increase in air speed is satisfactory for prompt acceleration to V: with:

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