---
kind: "section"
citation: "14 C.F.R. § 25.391"
title: "14"
number: "25.391"
heading: "Control surface loads: General."
url: "https://uscodex.org/cfr/14/25.391"
---

# §25.391. Control surface loads: General.


The control surfaces must be designed for the limit loads resulting from the flight conditions in §§ [25.331](/cfr/14/25.331.md), [25.341(a)](/cfr/14/25.341.md?p=a) and [(b)](/cfr/14/25.341.md?p=b), [25.349](/cfr/14/25.349.md), and [25.351](/cfr/14/25.351.md), considering the requirements for—

- (a) Loads parallel to hinge line, in [§ 25.393](/cfr/14/25.393.md);
- (b) Pilot effort effects, in [§ 25.397](/cfr/14/25.397.md);
- (c) Trim tab effects, in [§ 25.407](/cfr/14/25.407.md);
- (d) Unsymmetrical loads, in [§ 25.427](/cfr/14/25.427.md); and
- (e) Auxiliary aerodynamic surfaces, in [§ 25.445](/cfr/14/25.445.md).

## Notes

### Amendments

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-86, 61 FR 5222, Feb. 9, 1996; Amdt. 25-141, 79 FR 73468, Dec. 11, 2014]

### 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.

### Amendments

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as amended by Amdt. 25-86, 61 FR 5222, Feb. 9, 1996; Amdt. 25-141, 79 FR 73468, Dec. 11, 2014]