[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR25.143]
[Page 357-358]
TITLE 14--AERONAUTICS AND SPACE
CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
PART 25_AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES--Table
of Contents
Subpart B_Flight
Sec. 25.143 General.
(a) The airplane must be safely controllable and maneuverable
during--
(1) Takeoff;
(2) Climb;
(3) Level flight;
(4) Descent; and
(5) Landing.
(b) It must be possible to make a smooth transition from one flight
condition to any other flight condition without exceptional piloting
skill, alertness, or strength, and without danger of exceeding the
airplane limit-load factor under any probable operating conditions,
including--
(1) The sudden failure of the critical engine;
(2) For airplanes with three or more engines, the sudden failure of
the second critical engine when the airplane is in the en route,
approach, or landing configuration and is trimmed with the critical
engine inoperative; and
(3) Configuration changes, including deployment or retraction of
deceleration devices.
(c) The following table prescribes, for conventional wheel type
controls, the maximum control forces permitted during the testing
required by paragraphs (a) and (b) 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 75 50 .......
control--two hands available for control....
For short term application for pitch and roll 50 25 .......
control--one hand available for control.....
For short term application for yaw control... ....... ....... 150
[[Page 358]]
For long term application.................... 10 5 20
------------------------------------------------------------------------
(d) Approved operating procedures or conventional operating
practices must be followed when demonstrating compliance with the
control force limitations for short term application that are prescribed
in paragraph (c) of this section. The airplane must be in trim, or as
near to being in trim as practical, in the immediately preceding steady
flight condition. For the takeoff condition, the airplane must be
trimmed according to the approved operating procedures.
(e) When demonstrating compliance with the control force limitations
for long term application that are prescribed in paragraph (c) of this
section, the airplane must be in trim, or as near to being in trim as
practical.
(f) When maneuvering at a constant airspeed or Mach number (up to
VFC/MFC), 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 overstressed
inadvertently. Changes of gradient 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 overcontrolling.
(g) The maneuvering capabilities in a constant speed coordinated
turn at forward center of gravity, as specified in the following table,
must be free of stall warning or other characteristics that might
interfere with normal maneuvering:
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maneuvering bank
Configuration Speed angle in a Thrust power setting
coordinated turn
--------------------------------------------------------------------------------------------------------------------------------------------------------
Takeoff............................ V2 30[deg] Asymmetric WAT-Limited.\1\
Takeoff............................ \2\V2 + XX 40[deg] All-engines-operating climb.\3\
En route........................... VFTO 40[deg] Asymmetric WAT-Limited.\1\
Landing............................ VREF 40[deg] Symmetric for -3[deg] 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 Sec.
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 V2, or any lesser thrust or power setting that is used
for all-engines-operating initial climb procedures.
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-42,
43 FR 2321, Jan. 16, 1978; Amdt. 25-84, 60 FR 30749, June 9, 1995; Amdt.
25-108, 67 FR 70826, Nov. 26, 2002]