---
kind: "section"
citation: "14 C.F.R. § 27.351"
title: "14"
number: "27.351"
heading: "Yawing conditions."
url: "https://uscodex.org/cfr/14/27.351"
---

# §27.351. Yawing conditions.

- (a) Each rotorcraft must be designed for the loads resulting from the maneuvers specified in paragraphs [(b)](#b) and [(c)](#c) of this section with—
  - (1) Unbalanced aerodynamic moments about the center of gravity which the aircraft reacts to in a rational or conservative manner considering the principal masses furnishing the reacting inertia forces; and
  - (2) **Maximum main rotor speed.**
- (b) To produce the load required in [paragraph (a)](#a) of this section, in unaccelerated flight with zero yaw, at forward speeds from zero up to 0.6 VNE—
  - (1) Displace the cockpit directional control suddenly to the maximum deflection limited by the control stops or by the maximum pilot force specified in [§ 27.397(a)](/cfr/14/27.397.md?p=a);
  - (2) Attain a resulting sideslip angle or 90°, whichever is less; and
  - (3) **Return the directional control suddenly to neutral.**
- (c) To produce the load required in [paragraph (a)](#a) of this section, in unaccelerated flight with zero yaw, at forward speeds from 0.6 VNE up to VNE or VH, whichever is less—
  - (1) Displace the cockpit directional control suddenly to the maximum deflection limited by the control stops or by the maximum pilot force specified in [§ 27.397(a)](/cfr/14/27.397.md?p=a);
  - (2) Attain a resulting sideslip angle or 15°, whichever is less, at the lesser speed of VNE or VH;
  - (3) Vary the sideslip angles of paragraphs [(b)(2)](#b-2) and [(c)(2)](#c-2) of this section directly with speed; and
  - (4) **Return the directional control suddenly to neutral.**

## Notes

### Amendments

[Amdt. 27-26, 55 FR 7999, Mar. 6, 1990, as amended by Amdt. 27-34, 62 FR 46173, Aug. 29, 1997]

### 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.

### Amendments

[Amdt. 27-26, 55 FR 7999, Mar. 6, 1990, as amended by Amdt. 27-34, 62 FR 46173, Aug. 29, 1997]