54-25-02: Cam Drive Gear
FAA order 54-25-02 is an airworthiness directive. The FAA's subject line: Cam Drive Gear. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Engine
- Makes
- Curtiss-Wright/Marquette, Inc.
- Models
- Double Row Cyclone 975C18CB1, Double Row Turbo Cyclone 972TC18DA1 (R-3350-34, -91), Double Row Turbo Cyclone 972TC18DA2
Dates and paperwork
- Docket
- Unknown
- Status
- Current
- The FAA's document
- Read the order on the FAA's site
The order itself the regulatory text, as published
Show the full text (1,212 characters)
54-25-02 WRIGHT: Applies to All Models 975C18CB1, 972TC18DA1, and 972TC18DA2 Engines.
Compliance required as indicated.
I. Compliance required by November 1, 1955.
To alleviate front intermediate cam drive gear failures and associated possible engine overspeeding, the following intermediate cam drive gears must be removed from the front cam drive gear train: P/N's 138608, 138608 N, 171385, 171238, or 171387.
These gears may still be used in the rear cam drive configuration. Intermediate cam drive gears incorporating increased tooth width and thick hubs must be used in the front cam drive configuration. The following gears comply with this requirement: P/N's 171347, 171348, or 171994.
II. Compliance required at next and each subsequent overhaul.
To insure proper assembly of cam drive gear configurations, the following assembly instructions must be followed and applicable measurements recorded on engine build up sheets:
TC18DA Overhaul Manual:Section V. Instruction 17.
Section VIII. Instruction No. 2 plus referenced Table of Limits fits including Reference No. 238.
(Wright Aeronautical Division Service Bulletins Numbers C18C-83 and TC18-92 cover these same subjects.)
Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of November 6, 2026. Connections as data: /graph/directive/54-25-02.json · aircraft systems.