220 

14 CFR Ch. I (1–1–19 Edition) 

§ 25.143 

(2) During an approach and go- 

around; and 

(3) During an approach and landing. 
(d) The following table prescribes, for 

conventional wheel type controls, the 
maximum control forces permitted 
during the testing required by para-
graph (a) through (c) of this section: 

Force, in pounds, applied to the 

control wheel or rudder pedals 

Pitch Roll  Yaw 

For short term application for 

pitch and roll control—two 
hands available for control ....

75 

50 

For short term application for 

pitch and roll control—one 
hand available for control ......

50 

25 

For short term application for 

yaw control .............................

150 

For long term application ..........

10 

5 

20 

(e) Approved operating procedures or 

conventional operating practices must 
be followed when demonstrating com-
pliance with the control force limita-
tions for short term application that 
are prescribed in paragraph (d) of this 
section. The airplane must be in trim, 
or as near to being in trim as practical, 
in the preceding steady flight condi-
tion. For the takeoff condition, the air-
plane must be trimmed according to 
the approved operating procedures. 

(f) When demonstrating compliance 

with the control force limitations for 
long term application that are pre-
scribed in paragraph (d) of this section, 
the airplane must be in trim, or as near 
to being in trim as practical. 

(g) When maneuvering at a constant 

airspeed or Mach number (up to V

FC

/ 

M

FC

), the stick forces and the gradient 

of the stick force versus maneuvering 
load factor must lie within satisfactory 
limits. The stick forces must not be so 
great as to make excessive demands on 
the pilot’s strength when maneuvering 
the airplane, and must not be so low 
that the airplane can easily be over-
stressed inadvertently. Changes of gra-
dient that occur with changes of load 
factor must not cause undue difficulty 
in maintaining control of the airplane, 
and local gradients must not be so low 
as to result in a danger of overcontrol-
ling. 

(h) The maneuvering capabilities in a 

constant speed coordinated turn at for-
ward center of gravity, as specified in 
the following table, must be free of 
stall warning or other characteristics 
that might interfere with normal ma-
neuvering: 

Configuration Speed 

Maneuvering 

bank angle in a 

coordinated turn 

Thrust/power setting 

Takeoff ..........

V

2

 

30

° 

Asymmetric WAT-Limited.

1

 

Takeoff ..........

2

V

2

+ XX 

40

° 

All-engines-operating climb.

3

 

En route ........

V

FTO

 

40

° 

Asymmetric WAT-Limited.

1

 

Landing .........

V

REF

 

40

° 

Symmetric for 

¥

3

° 

flight path angle. 

1

A combination of weight, altitude, and temperature (WAT) such that the thrust or power setting produces the minimum climb 

gradient specified in § 25.121 for the flight condition. 

2

Airspeed approved for all-engines-operating initial climb. 

3

That thrust or power setting which, in the event of failure of the critical engine and without any crew action to adjust the thrust 

or power of the remaining engines, would result in the thrust or power specified for the takeoff condition at V

2

, or any lesser 

thrust or power setting that is used for all-engines-operating initial climb procedures. 

(i) When demonstrating compliance 

with § 25.143 in icing conditions— 

(1) Controllability must be dem-

onstrated with the most critical of the 
ice accretion(s) for the particular 
flight phase as defined in Appendices C 
and O of this part, as applicable, in ac-
cordance with § 25.21(g); 

(2) It must be shown that a push force 

is required throughout a pushover ma-
neuver down to a zero g load factor, or 
the lowest load factor obtainable if 
limited by elevator power or other de-
sign characteristic of the flight control 
system. It must be possible to prompt-

ly recover from the maneuver without 
exceeding a pull control force of 50 
pounds; and 

(3) Any changes in force that the 

pilot must apply to the pitch control to 
maintain speed with increasing sideslip 
angle must be steadily increasing with 
no force reversals, unless the change in 
control force is gradual and easily con-
trollable by the pilot without using ex-
ceptional piloting skill, alertness, or 
strength. 

(j) For flight in icing conditions be-

fore the ice protection system has been 

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