57-08-02: Parker Check Valve
FAA order 57-08-02 is an airworthiness directive. The FAA's subject line: Parker Check Valve. It names Bell 47: about 478 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
- Scotts-Bell 47 Inc
- Models
- 47B3, 47D, 47D1, 47G, 47H-1
- On this site
- Bell 47 478 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 (1,046 characters)
57-08-02 BELL: Applies to All Models 47B3, 47D, 47D1, 47G, and 47H1 Helicopters Equipped With Parker Check Valves in the Oil System.
Compliance required at next oil change and every 25 hours thereafter until replacement is accomplished.
Several failures of the hinge in the oil system Parker check valve, P/N 1111-517703, 1111-517704, or 1111-517744, have occurred resulting in restriction of the flow of oil from the pump. To preclude recurrence of such failures, the following must be accomplished:
1. At the next oil change and every 25 hours thereafter, remove, disassemble, and inspect the oil system Parker check valve, P/N 1111-517703, 1111-517704, or 1111-517744, for wear or failure of the hinge and freedom of operation. If defects are found, replace the valve.
2. James Pond Clark check valve, P/N 879A-10TT, has been approved as a replacement valve. The 25-hour inspection outlined above may be discontinued when the valve is installed.
(Bell Service Bulletin No. 119 dated March 15, 1957, covers this same subject.)
Related safety bulletins advice on the same designs, not orders
2001-02-09SW-01-13 ·
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/57-08-02.json · aircraft systems.