55-22-01: Oil Outlet Check Valve
FAA order 55-22-01 is an airworthiness directive. The FAA's subject line: Oil Outlet Check Valve. It names Beechcraft 35 Bonanza and Debonair: about 1,077 aircraft on the U.S. register today, though an order usually covers particular versions or serial numbers rather than every one. System: engine.
What it applies to as the FAA lists it
- Kind of product
- Aircraft
- Makes
- Textron Aviation Inc.
- Models
- 35, 35-33, 35-A33, 35-B33, 35-C33, 35-C33A, 35R
- On this site
- Beechcraft 35 Bonanza and Debonair 1,077 registered
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 (1,045 characters)
55-22-01 BEECH: Applies to All Model 35 Airplanes, Serial Numbers D-1 Through D- 550, Equipped With Unmodified Oil Tank Check Valves.
Compliance required as soon as possible but not later than January 1, 1956.
To prevent complete loss of the engine oil supply resulting from failure of oil supply line hose connects caused by engine counter rotation, the check valve located at oil tank outlet requires valve modification or removal of the valve internal parts. Modified valves supplied by Beech Aircraft (Beech P/N 35-939082) include 1/16-inch holes drilled in the face of the valve poppet to prevent pressure buildup in the oil supply line in case of engine counter rotation. Modified valves are not available from Beech Aircraft. Unmodified valves should have the internal parts (poppet pivot pin, spring and poppet) removed.
(Beech Service Bulletin Model 35, No. 30, issued July 15, 1955; Service Letter Model 35, No. 44, issued March 28, 1950, and Service Letter Model 35, No. 18, issued July 18, 1947, cover this same subject.)
Related safety bulletins advice on the same designs, not orders
2018-11-21SW-18-31 · NAVIGATION, ATTITUDE, AND DIRECTION DATA SYSTEM
2015-09-15CE-15-22 · Wing Leading Edge Hinge-Pin Corrosion
2012-06-19CE-12-36 · Flight Controls: Aileron
2012-02-07CE-12-18 · Flight Controls: Elevator Control Cable Condition
2011-02-16CE-11-21 · Flight Controls: Trailing Edge Flaps; Flap Nose Rib Cracking
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 October 26, 2026. Connections as data: /graph/directive/55-22-01.json · aircraft systems.