14 CFR § 25.1167 - Accessory gearboxes.

---
identifier: "/us/cfr/t14/s25.1167"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 25.1167 - Accessory gearboxes."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "25.1167"
section_name: "Accessory gearboxes."
chapter_name: "FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "AIRCRAFT"
part_number: "25"
part_name: "AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES"
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 and 44704; Pub. L. 115-254, 132 Stat 3281 (49 U.S.C. 44903 note)."
regulatory_source: "Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted."
cfr_part: "25"
---


# 25.1167 Accessory gearboxes.

For airplanes equipped with an accessory gearbox that is not certificated as part of an engine—

(a) The engine with gearbox and connecting transmissions and shafts attached must be subjected to the tests specified in § 33.49 or § 33.87 of this chapter, as applicable;

(b) The accessory gearbox must meet the requirements of §§ 33.25 and 33.53 or 33.91 of this chapter, as applicable; and

(c) Possible misalignments and torsional loadings of the gearbox, transmission, and shaft system, expected to result under normal operating conditions must be evaluated.

[Amdt. 25-38, 41 FR 55467, Dec. 20, 1976]