223 

Federal Aviation Administration, DOT 

§ 25.149 

(5) The airplane in the most critical 

takeoff configuration existing along 
the flight path after the airplane be-
comes airborne, except with the land-
ing gear retracted; 

(6) The airplane airborne and the 

ground effect negligible; and 

(7) If applicable, the propeller of the 

inoperative engine— 

(i) Windmilling; 
(ii) In the most probable position for 

the specific design of the propeller con-
trol; or 

(iii) Feathered, if the airplane has an 

automatic feathering device acceptable 
for showing compliance with the climb 
requirements of § 25.121. 

(d) The rudder forces required to 

maintain control at 

V

MC

may not ex-

ceed 150 pounds nor may it be nec-
essary to reduce power or thrust of the 
operative engines. During recovery, the 
airplane may not assume any dan-
gerous attitude or require exceptional 
piloting skill, alertness, or strength to 
prevent a heading change of more than 
20 degrees. 

(e) V

MCG

, the minimum control speed 

on the ground, is the calibrated air-
speed during the takeoff 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 takeoff to be 
safely continued using normal piloting 
skill. In the determination of V

MCG

, as-

suming 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 engine is made inoperative to 
the point at which recovery to a direc-
tion parallel to the centerline is com-
pleted may not deviate more than 30 
feet laterally from the centerline at 
any point. V

MCG

must be established 

with— 

(1) The airplane in each takeoff con-

figuration or, at the option of the ap-
plicant, in the most critical takeoff 
configuration; 

(2) Maximum available takeoff power 

or thrust on the operating engines; 

(3) The most unfavorable center of 

gravity; 

(4) The airplane trimmed for takeoff; 

and 

(5) The most unfavorable weight in 

the range of takeoff weights. 

(f) V

MCL

, the minimum control speed 

during approach and landing with all 
engines operating, is the calibrated air-
speed at which, when the critical en-
gine is suddenly made inoperative, it is 
possible to maintain control of the air-
plane with that engine still inoper-
ative, and maintain straight flight 
with an angle of bank of not more than 
5 degrees. V

MCL

must be established 

with— 

(1) The airplane in the most critical 

configuration (or, at the option of the 
applicant, each configuration) for ap-
proach and landing with all engines op-
erating; 

(2) The most unfavorable center of 

gravity; 

(3) The airplane trimmed for ap-

proach with all engines operating; 

(4) The most favorable weight, or, at 

the option of the applicant, as a func-
tion of weight; 

(5) For propeller airplanes, the pro-

peller of the inoperative engine in the 
position it achieves without pilot ac-
tion, assuming the engine fails while at 
the power or thrust necessary to main-
tain a three degree approach path 
angle; and 

(6) Go-around power or thrust setting 

on the operating engine(s). 

(g) For airplanes with three or more 

engines, V

MCL-2

, the minimum control 

speed during approach and landing 
with one critical engine inoperative, is 
the calibrated airspeed at which, when 
a second critical engine is suddenly 
made inoperative, it is possible to 
maintain control of the airplane with 
both engines still inoperative, and 
maintain straight flight with an angle 
of bank of not more than 5 degrees. 
V

MCL-2

must be established with— 

(1) The airplane in the most critical 

configuration (or, at the option of the 
applicant, each configuration) for ap-
proach and landing with one critical 
engine inoperative; 

(2) The most unfavorable center of 

gravity; 

(3) The airplane trimmed for ap-

proach with one critical engine inoper-
ative; 

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