- Effective
- August 24, 1974
- Model
- F-28A
- Data sheet
- TCDSH1CE
- Registered aircraft
- 39 matched by model
- Product
- Aircraft · Rotorcraft
- Amendment
- 39-1925
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 | 19 KB | 40d82429…d8ed4dd | FAA DRS (API key needed) |
On this page
The airworthiness directive
74-17-07 ENSTROM: Amendment 39-1925. Applies to the following Enstrom Model F- 28A main rotor gearboxes, Serial Numbers: 03A, 016, 025, 041, 050, 063, 073, 082, 09-02-69, 08-001-72, and 20-001-72.
Compliance required as indicated unless already accomplished:
(a) All main rotor gearboxes in this group with a total time since remanufacture of 100 hours or more must be returned to the Enstrom facility for teardown and inspection within the next 5 hours.
(b) All main rotor gearboxes in this group with a total time since remanufacture of less than 100 hours should be returned to the Enstrom facility for teardown and inspection before accumulating 100 hours.
This amendment becomes effective August 24, 1974.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 39
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1966 | 1 |
|---|---|
| 1968 | 1 |
| 1969 | 3 |
| 1971 | 3 |
| 1972 | 5 |
| 1973 | 2 |
| 1974 | 8 |
| 1975 | 7 |
9 with no year recorded