214 

14 CFR Ch. I (1–1–19 Edition) 

§ 25.111 

Where— 

Tire Pressure = maximum airplane operating 

tire pressure (psi); 

µ

t/gMAX

= maximum tire-to-ground braking 

coefficient; 

V = airplane true ground speed (knots); and 
Linear interpolation may be used for tire 

pressures other than those listed. 

(e) Except as provided in paragraph 

(f)(1) of this section, means other than 
wheel brakes may be used to determine 
the accelerate-stop distance if that 
means— 

(1) Is safe and reliable; 
(2) Is used so that consistent results 

can be expected under normal oper-
ating conditions; and 

(3) Is such that exceptional skill is 

not required to control the airplane. 

(f) The effects of available reverse 

thrust— 

(1) Shall not be included as an addi-

tional means of deceleration when de-
termining the accelerate-stop distance 
on a dry runway; and 

(2) May be included as an additional 

means of deceleration using rec-
ommended reverse thrust procedures 
when determining the accelerate-stop 
distance on a wet runway, provided the 
requirements of paragraph (e) of this 
section are met. 

(g) The landing gear must remain ex-

tended throughout the accelerate-stop 
distance. 

(h) If the accelerate-stop distance in-

cludes a stopway with surface charac-
teristics substantially different from 
those of the runway, the takeoff data 
must include operational correction 
factors for the accelerate-stop dis-
tance. The correction factors must ac-
count for the particular surface charac-

teristics of the stopway and the vari-
ations in these characteristics with 
seasonal weather conditions (such as 
temperature, rain, snow, and ice) with-
in the established operational limits. 

(i) A flight test demonstration of the 

maximum brake kinetic energy accel-
erate-stop distance must be conducted 
with not more than 10 percent of the 
allowable brake wear range remaining 
on each of the airplane wheel brakes. 

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as 
amended by Amdt. 25–42, 43 FR 2321, Jan. 16, 
1978; Amdt. 25–92, 63 FR 8318, Feb. 18, 1998] 

§ 25.111

Takeoff path. 

(a) The takeoff path extends from a 

standing start to a point in the takeoff 
at which the airplane is 1,500 feet above 
the takeoff surface, or at which the 
transition from the takeoff to the en 
route configuration is completed and 
V

FTO

is reached, whichever point is 

higher. In addition— 

(1) The takeoff path must be based on 

the procedures prescribed in § 25.101(f); 

(2) The airplane must be accelerated 

on the ground to 

V

EF,

at which point 

the critical engine must be made inop-
erative and remain inoperative for the 
rest of the takeoff; and 

(3) After reaching 

V

EF,

the airplane 

must be accelerated to 

V

2

. 

(b) During the acceleration to speed 

V

2

, the nose gear may be raised off the 

ground at a speed not less than 

V

R

. 

However, landing gear retraction may 
not be begun until the airplane is air-
borne. 

(c) During the takeoff path deter-

mination in accordance with para-
graphs (a) and (b) of this section— 

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