- Models
- HRS-1/CH-19, HRS-3/H-19B, S-55, S-55B, S-55C
- Registered aircraft
- 17 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 | 19 KB | 7e2e8346…9cc15a1 | FAA DRS (API key needed) |
On this page
The airworthiness directive
56-23-03 SIKORSKY: Applies to All Model S-55 Helicopters.
Compliance required as indicated.
Due to additional failures, it has been found necessary to lower the retirement time specified in AD 56-10-02. Accordingly, the horizontal hinge pin assembly, P/N S10-10-3331 and S10-10-3331-1 with 750 hours service must be replaced by December 1, 1956, or prior to the accumulation of 850 hours, whichever occurs first. Parts with 850 hours or more must be replaced prior to further service. Thereafter, P/N S10-10-3331 and S10-10-3331-1 are to be retired at not more than 750 hours.
This supersedes AD 56-10-02.
Affected TCDS · 2
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 17
Registered aircraft whose airframe or engine model this AD names. Matched by model only, so check each against the AD’s applicability.
| 1952 | 1 |
|---|---|
| 1953 | 1 |
| 1954 | 3 |
| 1955 | 3 |
| 1956 | 2 |
| 1957 | 2 |
| 1959 | 1 |
| 1996 | 1 |
| 1997 | 1 |
2 with no year recorded