Section 25.333

14 CFR Ch. I (1-1-19 Edition)

t2 = t1 + Dt
tmax = t2 + /w;
Dt = the minimum period of time necessary
to allow the prescribed limit load factor

(C) tmax..
[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25-23, 35 FR 5672, Apr. 8,
1970; Amdt. 25-46, 43 FR 50594, Oct. 30, 1978; 43
FR 52495, Nov. 13, 1978; 43 FR 54082, Nov. 20,
1978; Amdt. 25-72, 55 FR 29775, July 20, 1990; 55
FR 37607, Sept. 12, 1990; Amdt. 25-86, 61 FR
5220, Feb. 9, 1996; Amdt. 25-91, 62 FR 40704,
July 29, 1997; Amdt. 25-141, 79 FR 73466, Dec.
11, 2014]

Section 25.333 Flight maneuvering envelope.
(a) General. The strength requirements must be met at each combination of airspeed and load factor on and
within the boundaries of the representative maneuvering envelope (V-n diagram) of paragraph (b) of this section.
This envelope must also be used in determining the airplane structural operating limitations as specified in
Section 25.1501.
(b) Maneuvering envelope.

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(iv) In cases where the flight deck
pitch control motion may be affected
by inputs from systems (for example,
by a stick pusher that can operate at
high load factor as well as at 1g), then
the effects of those systems shall be
taken into account.
(v) Airplane loads that occur beyond
the following times need not be considered:
(A) For the nose-up pitching maneuver, the time at which the normal acceleration at the center of gravity goes
below 0g;
(B) For the nose-down pitching maneuver, the time at which the normal
acceleration at the center of gravity
goes above the positive limit load factor prescribed in Section 25.337;

to be achieved in the initial direction,
but it need not exceed five seconds (see
figure below).