---
kind: "range"
citation: "14 C.F.R. §§ 29.471–29.475"
title: "14"
from: "29.471"
to: "29.475"
count: 3
url: "https://uscodex.org/cfr/14/29.471..29.475"
---

# §29.471. General.

- (a) **Loads and equilibrium.** For limit ground loads—
  - (1) The limit ground loads obtained in the landing conditions in this part must be considered to be external loads that would occur in the rotorcraft structure if it were acting as a rigid body; and
  - (2) In each specified landing condition, the external loads must be placed in equilibrium with linear and angular inertia loads in a rational or conservative manner.
- (b) **Critical centers of gravity.** The critical centers of gravity within the range for which certification is requested must be selected so that the maximum design loads are obtained in each landing gear element.

# §29.473. Ground loading conditions and assumptions.

- (a) For specified landing conditions, a design maximum weight must be used that is not less than the maximum weight. A rotor lift may be assumed to act through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the design maximum weight.
- (b) Unless otherwise prescribed, for each specified landing condition, the rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor substantiated under [§ 29.725](/cfr/14/29.725.md).
- (c) Triggering or actuating devices for additional or supplementary energy absorption may not fail under loads established in the tests prescribed in §§ [29.725](/cfr/14/29.725.md) and [29.727](/cfr/14/29.727.md), but the factor of safety prescribed in [§ 29.303](/cfr/14/29.303.md) need not be used.

# §29.475. Tires and shock absorbers.


Unless otherwise prescribed, for each specified landing condition, the tires must be assumed to be in their static position and the shock absorbers to be in their most critical position.