[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: 14CFR25.177]



[Page 364]

 

                     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. 25.177  Static lateral-directional stability.



    (a)-(b) [Reserved]

    (c) In straight, steady sideslips, the aileron and rudder control 

movements and forces must be substantially proportional to the angle of 

sideslip in a stable sense; and the factor of proportionality must lie 

between limits found necessary for safe operation throughout the range 

of sideslip angles appropriate to the operation of the airplane. At 

greater angles, up to the angle at which full rudder is used or a rudder 

force of 180 pounds is obtained, the rudder pedal forces may not 

reverse; and increased rudder deflection must be needed for increased 

angles of sideslip. Compliance with this paragraph must be demonstrated 

for all landing gear and flap positions and symmetrical power conditions 

at speeds from 1.13 VSR1 to VFE, VLE, or VFC/MFC, as appropriate.

    (d) The rudder gradients must meet the requirements of paragraph (c) 

at speeds between VMO/MMO and VFC/MFC except that the 

dihedral effect (aileron deflection opposite the corresponding rudder 

input) may be negative provided the divergence is gradual, easily 

recognized, and easily controlled by the pilot.



[Amdt. 25-72, 55 FR 29774, July 20, 1990; 55 FR 37607, Sept. 12, 1990; 

Amdt. 25-108, 67 FR 70827, Nov. 26, 2002]