- Model
- S-51
- Data sheet
- TCDSH-2
- 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 | b3cb99a8…af94605 | FAA DRS (API key needed) |
On this page
The airworthiness directive
51-22-01 SIKORSKY: Applies to All Model S-51 Helicopters.
Compliance required within the next 25 hours of operation, but not later than November 1, 1951.
Due to the reported failures of Gear Shaft (Generator Drive-Tail Drive Transmission System) P/N S-10-35-1004, all shafts in service shall be replaced by shafts which have been jig drilled (i.e., the taper pin hole is located squarely with respect to the splines) and which have been stoned and polished to deburr and remove any sharp radii where the taper pin hole intersects the splines.
(Sikorsky Service Information Circular No. 172, dated August 30, 1951, covers this same subject.)
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.