---
kind: "section"
citation: "14 C.F.R. § 25.393"
title: "14"
number: "25.393"
heading: "Loads parallel to hinge line."
url: "https://uscodex.org/cfr/14/25.393"
---

# §25.393. Loads parallel to hinge line.

- (a) Control surfaces and supporting hinge brackets must be designed for inertia loads acting parallel to the hinge line.
- (b) In the absence of more rational data, the inertia loads may be assumed to be equal to KW, where—
  - (1) **K—** = 24 for vertical surfaces;
  - (2) **K—** = 12 for horizontal surfaces; and
  - (3) **W—** = weight of the movable surfaces.

## Notes

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701, 44702 and 44704; Pub. L. 115-254, 132 Stat 3281 (49 U.S.C. 44903 note).

### Source

Source: Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted.