14 CFR § 27.921 - Rotor brake.

---
identifier: "/us/cfr/t14/s27.921"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 27.921 - Rotor brake."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "27.921"
section_name: "Rotor brake."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "AIRCRAFT"
part_number: "27"
part_name: "AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 106(f), 106(g), 40113, 44701-44702, 44704."
regulatory_source: "Docket No. 5074, 29 FR 15695, Nov. 24, 1964, unless otherwise noted."
cfr_part: "27"
---


# 27.921 Rotor brake.

If there is a means to control the rotation of the rotor drive system independently of the engine, any limitations on the use of that means must be specified, and the control for that means must be guarded to prevent inadvertent operation.