- Models
- 47B3, 47D, 47D1, 47G, 47H-1
- Data sheet
- TCDSH-1
- Registered aircraft
- 119 matched by model
- Product
- Aircraft · Rotorcraft
Unofficial copy of the text in the FAA’s Dynamic Regulatory System. The FAA’s own copy is the authoritative one. DRS record last changed May 30, 2024.
Copies of the files this page was built from, with their SHA-256. Retrieved October 18, 2026.
| File | Size | SHA-256 | Original |
|---|---|---|---|
| FAA DRS HTML | 20 KB | 2f9af2e1…fb28cbd | FAA DRS (API key needed) |
On this page
The airworthiness directive
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.)
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 119
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1947 | 10 |
|---|---|
| 1948 | 3 |
| 1949 | 3 |
| 1950 | 2 |
| 1951 | 6 |
| 1952 | 8 |
| 1953 | 7 |
| 1954 | 8 |
| 1955 | 6 |
| 1956 | 9 |
| 1957 | 5 |
| 1958 | 1 |
| 1959 | 3 |
| 1960 | 2 |
| 1963 | 6 |
| 1964 | 1 |
| 1965 | 3 |
| 1966 | 1 |
| 1967 | 2 |
| 1969 | 1 |
| 1972 | 1 |
| 1979 | 1 |
30 with no year recorded