[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR23.173]

[Page 191]
 
                     TITLE 14--AERONAUTICS AND SPACE
 
CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION
 
PART 23--AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES--Table of Contents
 
                            Subpart B--Flight
 
Sec. 23.173  Static longitudinal stability.

    Under the conditions specified in Sec. 23.175 and with the airplane 
trimmed as indicated, the characteristics of the elevator control forces 
and the friction within the control system must be as follows:
    (a) A pull must be required to obtain and maintain speeds below the 
specified trim speed and a push required to obtain and maintain speeds 
above the specified trim speed. This must be shown at any speed that can 
be obtained, except that speeds requiring a control force in excess of 
40 pounds or speeds above the maximum allowable speed or below the 
minimum speed for steady unstalled flight, need not be considered.
    (b) The airspeed must return to within the tolerances specified for 
applicable categories of airplanes when the control force is slowly 
released at any speed within the speed range specified in paragraph (a) 
of this section. The applicable tolerances are--
    (1) The airspeed must return to within plus or minus 10 percent of 
the original trim airspeed; and
    (2) For commuter category airplanes, the airspeed must return to 
within plus or minus 7.5 percent of the original trim airspeed for the 
cruising condition specified in Sec. 23.175(b).
    (c) The stick force must vary with speed so that any substantial 
speed change results in a stick force clearly perceptible to the pilot.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-14, 
38 FR 31820 Nov. 19, 1973; Amdt. 23-34, 52 FR 1828, Jan. 15, 1987]