Code of Federal Regulations - Title 14

225

Federal Aviation Administration, DOT

§ 23.499

and the drag loads may be assumed to
be zero.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as
amended by Amdt. 23–45, 58 FR 42160, Aug. 6,
1993]

§ 23.493

Braked roll conditions.

Under braked roll conditions, with

the shock absorbers and tires in their
static positions, the following apply:

(a) The limit vertical load factor

must be 1.33.

(b) The attitudes and ground con-

tacts must be those described in § 23.479
for level landings.

vertical reaction at the wheel multi-
plied by a coefficient of friction of 0.8
must be applied at the ground contact
point of each wheel with brakes, except
that the drag reaction need not exceed
the maximum value based on limiting
brake torque.

§ 23.497

Supplementary conditions for

tail wheels.

In determining the ground loads on

the tail wheel and affected supporting
structures, the following apply:

(a) For the obstruction load, the

limit ground reaction obtained in the
tail down landing condition is assumed
to act up and aft through the axle at 45
degrees. The shock absorber and tire
may be assumed to be in their static
positions.

(b) For the side load, a limit vertical

ground reaction equal to the static
load on the tail wheel, in combination
with a side component of equal mag-
nitude, is assumed. In addition—

(1) If a swivel is used, the tail wheel

is assumed to be swiveled 90 degrees to
the airplane longitudinal axis with the
resultant ground load passing through
the axle;

(2) If a lock, steering device, or shim-

my damper is used, the tail wheel is
also assumed to be in the trailing posi-
tion with the side load acting at the
ground contact point; and

(3) The shock absorber and tire are

assumed to be in their static positions.

ergy absorption device is provided to
show compliance with § 23.925(b), the
following apply:

(1) Suitable design loads must be es-

tablished for the tail wheel, bumper, or
energy absorption device; and

(2) The supporting structure of the

tail wheel, bumper, or energy absorp-
tion device must be designed to with-
stand the loads established in para-
graph (c)(1) of this section.

[Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as
amended by Amdt. 23–48, 61 FR 5147, Feb. 9,
1996]

§ 23.499

Supplementary conditions for

nose wheels.

In determining the ground loads on

nose wheels and affected supporting
structures, and assuming that the
shock absorbers and tires are in their
static positions, the following condi-
tions must be met:

(a) For aft loads, the limit force com-

ponents at the axle must be—

(1) A vertical component of 2.25 times

the static load on the wheel; and

(2) A drag component of 0.8 times the

vertical load.

(b) For forward loads, the limit force

components at the axle must be—

(1) A vertical component of 2.25 times

the static load on the wheel; and

(2) A forward component of 0.4 times

the vertical load.

components at ground contact must
be—

(1) A vertical component of 2.25 times

the static load on the wheel; and

(2) A side component of 0.7 times the

vertical load.

(d) For airplanes with a steerable

nose wheel that is controlled by hy-
draulic or other power, at design take-
off weight with the nose wheel in any
steerable position, the application of
1.33 times the full steering torque com-
bined with a vertical reaction equal to
1.33 times the maximum static reaction
on the nose gear must be assumed.
However, if a torque limiting device is
installed, the steering torque can be re-
duced to the maximum value allowed
by that device.

(e) For airplanes with a steerable

nose wheel that has a direct mechan-
ical connection to the rudder pedals,
the mechanism must be designed to
withstand the steering torque for the

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