14 CFR § 27.661 - Rotor blade clearance.

---
identifier: "/us/cfr/t14/s27.661"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 27.661 - Rotor blade clearance."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "27.661"
section_name: "Rotor blade clearance."
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"
---


# 27.661 Rotor blade clearance.

There must be enough clearance between the rotor blades and other parts of the structure to prevent the blades from striking any part of the structure during any operating condition.

[Amdt. 27-2, 33 FR 963, Jan. 26, 1968]