[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR25.253]

[Page 361-362]
 
                     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. 25.253  High-speed characteristics.

    (a) Speed increase and recovery characteristics. The following speed 
increase and recovery characteristics must be met:
    (1) Operating conditions and characteristics likely to cause 
inadvertent speed increases (including upsets in pitch and roll) must be 
simulated with the airplane trimmed at any likely cruise speed up to 
VMO/MMO. These conditions and characteristics 
include gust upsets, inadvertent control movements, low stick force 
gradient in relation to control friction, passenger movement, leveling 
off from climb, and descent from Mach to airspeed limit altitudes.
    (2) Allowing for pilot reaction time after effective inherent or 
artificial speed warning occurs, it must be shown that the airplane can 
be recovered to a normal attitude and its speed reduced to 
VMO/MMO, without-
    (i) Exceptional piloting strength or skill;
    (ii) Exceeding VD/MD, VDF/
MDF, or the structural limitations; and
    (iii) Buffeting that would impair the pilot's ability to read the 
instruments or control the airplane for recovery.
    (3) With the airplane trimmed at any speed up to VMO/
MMO, there must be no reversal of the response to control 
input about any axis at any speed up to

[[Page 362]]

VDF/MDF. Any tendency to pitch, roll, or yaw must 
be mild and readily controllable, using normal piloting techniques. When 
the airplane is trimmed at VMO/MMO, the slope of 
the elevator control force versus speed curve need not be stable at 
speeds greater than VFC/MFC, but there must be a 
push force at all speeds up to VDF/MDF and there 
must be no sudden or excessive reduction of elevator control force as 
VDF/MDF is reached.
    (b) Maximum speed for stability characteristics, VFC/
MFC. VFC/MFC is the maximum speed at 
which the requirements of Secs. 25.143(f), 25.147(e), 25.175(b)(1), 
25.177, and 25.181 must be met with flaps and landing gear retracted. It 
may not be less than a speed midway between VMO/
MMO and VDF/MDF, except that for 
altitudes where Mach number is the limiting factor, MFC need 
not exceed the Mach number at which effective speed warning occurs.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-23, 
35 FR 5671, Apr. 8, 1970; Amdt. 25-54, 45 FR 60172, Sept. 11, 1980; 
Amdt. 25-72, 55 FR 29775, July 20, 1990; Amdt. 25-84, 60 FR 30750, June 
9, 1995]