[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: 14CFR23.181]



[Page 198-199]

 

                     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. 23.181  Dynamic stability.



    (a) Any short period oscillation not including combined lateral-

directional oscillations occurring between the stalling speed and the 

maximum allowable speed appropriate to the configuration of the airplane 

must be heavily damped with the primary controls--

    (1) Free; and

    (2) In a fixed position.

    (b) Any combined lateral-directional oscillations (``Dutch roll'') 

occurring between the stalling speed and the maximum allowable speed 

appropriate to the configuration of the airplane must be damped to 1/10 

amplitude in 7 cycles with the primary controls--

    (1) Free; and

    (2) In a fixed position.

    (c) If it is determined that the function of a stability 

augmentation system, reference Sec. 23.672, is needed to meet the 

flight characteristic requirements of this part, the primary control 

requirements of paragraphs (a)(2) and (b)(2) of this section are not 

applicable to the tests needed to verify the acceptability of that 

system.

    (d) During the conditions as specified in Sec. 23.175, when the 

longitudinal control force required to maintain speeds differing from 

the trim speed by at



[[Page 199]]



least plus and minus 15 percent is suddenly released, the response of 

the airplane must not exhibit any dangerous characteristics nor be 

excessive in relation to the magnitude of the control force released. 

Any long-period oscillation of flight path, phugoid oscillation, that 

results must not be so unstable as to increase the pilot's workload or 

otherwise endanger the airplane.



[Amdt. 23-21, 43 FR 2318, Jan. 16, 1978, as amended by Amdt. 23-45, 58 

FR 42158, Aug. 6, 1993]



                                 Stalls