---
kind: "section"
citation: "14 C.F.R. § 27.505"
title: "14"
number: "27.505"
heading: "Ski landing conditions."
url: "https://uscodex.org/cfr/14/27.505"
---

# §27.505. Ski landing conditions.


If certification for ski operation is requested, the rotorcraft, with skis, must be designed to withstand the following loading conditions (where P is the maximum static weight on each ski with the rotorcraft at design maximum weight, and n is the limit load factor determined under [§ 27.473(b)](/cfr/14/27.473.md?p=b).

- (a) **Up-load conditions in which—**
  - (1) A vertical load of Pn and a horizontal load of Pn/4 are simultaneously applied at the pedestal bearings; and
  - (2) A vertical load of 1.33 P is applied at the pedestal bearings.
- (b) A side-load condition in which a side load of 0.35 Pn is applied at the pedestal bearings in a horizontal plane perpendicular to the centerline of the rotorcraft.
- (c) A torque-load condition in which a torque load of 1.33 P (in foot pounds) is applied to the ski about the vertical axis through the centerline of the pedestal bearings.

## Notes

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701-44702, 44704.

### Source

Source: Docket No. 5074, 29 FR 15695, Nov. 24, 1964, unless otherwise noted.