(1)
The two critical engines must be inoperative with their propellers (if appli-cable) inthe minimumdragposition;

(2)
Reserved.

(3)
The .aps must be in the most favorable climb position.

(c)
Lateral control;general. It must be possible to make 20'banked turns, with and against the inoperative engine, from steady .ight at a speed equal to [1.3 VSR1] with–

(1)
The critical engineinoperative anditspropeller(if applicable)in the minimum drag position;

(2)
The remaining engines at maximum continuouspower;

(3)
The most unfavorable center of gravity;

(4)
Landinggear(i) retracted and(ii) extended;

(5)
Flaps in the most favorable climb position; and

(6)
Maximum takeo. weight.

(d)
Lateral control; airplanes withfour or more engines. Airplanes with four or more engines must be able to make 20'banked turns, with and against the inoperative engines,fromsteady.ight at aspeed equalto[1.3VSR1], with maximum continuous power, and with the airplanein the con.gurationprescribedbyparagraph(b) of this section.

(e)
Lateral control; all enginesoperating.With the engines operating, roll response must allow normal maneuvers(such as recovery from upsetsproducedbygusts andthe initiation of evasive maneuvers). There must be enough excess lateral control in sideslips (up to sideslip angles that might be required in normal operation), to allow a limited amount of maneuvering and to correct for gusts. Lateral control mustbe enough at any speed up to VFC/MFC toprovide apeak roll rate necessary for safety, without excess control forces or travel.

Amdt. 25-108, E.. 12/26/2002
FAR 25.149 : Minimum control speed.
(a)
In establishing the minimum control speeds required by this section, the method used to simulate critical engine failure must represent the most critical mode of powerplant failure with respect to controllability expected in service.

(b)
VMC is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine still inoperative and maintain straight .ight with an angle of bank of not more than 5 degrees.

(c)
[VMC may not exceed 1.13VSR with–]

(1)
Maximum available takeo. power or thrust on the engines;

(2)
The most unfavorable center of gravity;

(3)
The airplane trimmed for takeo.;

(4)
The maximum sealevel takeo. weight(or any lesser weight necessary to show VMC );

(5)
The airplane in the most critical takeo. con.guration existing along the .ight path after the airplanebecomes airborne, except with the landinggear retrac-ted;

(6)
The airplane airborne and the ground e.ect negligible; and

(7)
If applicable, the propeller of the inoperative engine–

(i) Windmilling;
′
Elodie Roux. Septembre 2003
Subpart B : Flight
(ii) In the most probable position for the speci.c design of the propeller control; or
(iii) Feathered, if the airplane has an automatic feathering device acceptable for showing compliance with the climb requirements of Sec. 25.121.
(d)
The rudder forces required to maintain control at VMC may not exceed150pounds normayitbe necessary to reducepowerorthrust of the operativeengines.During recovery,the airplane may not assume anydangerous attitude or require exceptional piloting skill, alertness, or strength to prevent a heading change of more than 20 degrees.

(e)
VMCG, the minimum control speed on the ground, is the calibrated airspeed during the takeo. run at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane using the rudder control alone (without the use of nosewheel steering), as limited by 150 pounds of force, and the lateral control to the extent of keeping the wings level to enable the takeo. to be safely continued using normal piloting skill. In the determination of VMCG, assuming that the path of the airplane accelerating with all engines operating is along the centerline of the runway, its path from the point at which the critical engineis madeinoperativetothepoint at which recovery to adirectionparallel to the centerline is completed may not deviate more than 30 feet laterally from the centerline at any point. VMCG must be established with–
　
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本文鏈接地址：FAA規章 美國聯邦航空規章 Federal Aviation Regulations 3(34)