- Effective
- February 17, 1965
- Published
- February 17, 1965
- Models
- 47, 47B, 47B3, 47D, 47D1, 47E and 18 more
- Registered aircraft
- 490 matched by model
- Product
- Aircraft · Rotorcraft
- Amendment
- 39-36
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 | db7ab123…12f011d | FAA DRS (API key needed) |
On this page
The airworthiness directive
65-04-01 BELL: Amdt. 39-36 Part 39 Federal Register February 17, 1965. Applies to Model 47 Series Helicopters Equipped With Transmissions Serial Numbers B12-885 through B12-969.
Compliance required within 25 hours' time in service after the effective date of this AD, unless previously accomplished in accordance with Bell Helicopter Company Service Bulletin No. 141SB.
Some of the P/N 47-620-535-1 outer races installed in the freewheeling clutch of transmissions listed herein may not have been tempered properly. To eliminate the possibility of excessive wear of these races and subsequent malfunction of the freewheeling clutch, conduct a hardness test on these races as described by Bell Service Bulletin No. 141SB. If the hardness does not fall within the limits prescribed by the bulletin, replace the outer race with one which is within the limits before further flight.
This directive effective February 17, 1965.
Affected TCDS · 3
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 490
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1946 | 1 |
|---|---|
| 1947 | 10 |
| 1948 | 5 |
| 1949 | 3 |
| 1950 | 2 |
| 1951 | 7 |
| 1952 | 8 |
| 1953 | 8 |
| 1954 | 9 |
| 1955 | 7 |
| 1956 | 19 |
| 1957 | 18 |
| 1958 | 18 |
| 1959 | 10 |
| 1960 | 10 |
| 1961 | 9 |
| 1962 | 12 |
| 1963 | 20 |
| 1964 | 18 |
| 1965 | 20 |
| 1966 | 33 |
| 1967 | 28 |
| 1968 | 20 |
| 1969 | 12 |
| 1970 | 8 |
| 1971 | 12 |
| 1972 | 14 |
| 1973 | 10 |
| 1974 | 4 |
| 1975 | 2 |
| 1976 | 1 |
| 1979 | 1 |
| 1980 | 1 |
| 1981 | 1 |
| 2010 | 1 |
128 with no year recorded