[Code of Federal Regulations]
[Title 14, Volume 1]
[Revised as of January 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 14CFR25.207]

[Page 367-368]
 
                     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.  25.207  Stall warning.

    (a) Stall warning with sufficient margin to prevent inadvertent 
stalling with the flaps and landing gear in any normal position must be 
clear and distinctive to the pilot in straight and turning flight.
    (b) The warning must be furnished either through the inherent 
aerodynamic qualities of the airplane or by a device that will give 
clearly distinguishable indications under expected conditions of flight. 
However, a visual stall warning device that requires the attention of 
the crew within the cockpit is not acceptable by itself. If a warning 
device is used, it must provide a warning in each of the airplane 
configurations prescribed in paragraph (a) of this section at the speed 
prescribed in paragraphs (c) and (d) of this section.
    (c) When the speed is reduced at rates not exceeding one knot per 
second, stall warning must begin, in each normal configuration, at a 
speed, VSW, exceeding the speed at which the stall is 
identified in accordance with Sec.  25.201(d) by not less than five 
knots or five percent CAS, whichever is greater. Once initiated, stall 
warning must continue until the angle of attack is reduced to 
approximately that at which stall warning began.
    (d) In addition to the requirement of paragraph (c) of this section, 
when the speed is reduced at rates not exceeding one knot per second, in 
straight flight with engines idling and at the center-of-gravity 
position specified in Sec.  25.103(b)(5), VSW, in each normal 
configuration, must exceed VSR by not less than three knots 
or three percent CAS, whichever is greater.
    (e) The stall warning margin must be sufficient to allow the pilot 
to prevent stalling (as defined in Sec.  25.201(d)) when recovery is 
initiated not less than one second after the onset of stall warning in 
slow-down turns with at least 1.5g load factor normal to the flight path

[[Page 368]]

and airspeed deceleration rates of at least 2 knots per second, with the 
flaps and landing gear in any normal position, with the airplane trimmed 
for straight flight at a speed of 1.3 VSR, and with the power 
or thrust necessary to maintain level flight at 1.3 VSR.
    (f) Stall warning must also be provided in each abnormal 
configuration of the high lift devices that is likely to be used in 
flight following system failures (including all configurations covered 
by Airplane Flight Manual procedures).

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-7, 30 
FR 13118, Oct. 15, 1965; Amdt. 25-42, 43 FR 2322, Jan. 16, 1978; Amdt. 
25-108, 67 FR 70827, Nov. 26, 2002]

                Ground and Water Handling Characteristics