- Models
- 47B, 47B3, 47D, 47D1
- Data sheet
- TCDSH-1
- Registered aircraft
- 54 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 | e8411482…832826a | FAA DRS (API key needed) |
On this page
The airworthiness directive
51-26-01 BELL: Applies to All Models 47B, 47B3, 47D, 47D1 Helicopters.
A. Compliance required by October 15, 1951, unless Bell Service Instruction 67S1 has been accomplished already.
To provide additional strength to preclude the possibility of tail rotor failures, wrap each tail rotor blade across the junction of the stainless steel leading edge at the root end area of each blade with two strips of unidirectional fiberglass cloth, Bell P/N 47-642-020-14.
(Bell Service Bulletin No. 75 covers this same subject.)
B. Compliance required daily.
Inspect the tail rotor stainless steel leading edge for evidence of loosening or lifting. Carefully inspect the 3/32 radius, the flanges of leading edge at forward edge of reinforcement plates, and the entire root area for cracks. Replace blades immediately if any of these conditions exist.
(Bell Service Bulletin No. 75, revised October 11, 1951, covers this same subject.)
This supersedes AD 51-23-01.
Affected TCDS · 1
The type certificate data sheets for the models this AD names, matched by model and maker.
Registered aircraft · 54
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 | 7 |
| 1948 | 3 |
| 1949 | 3 |
| 1950 | 2 |
| 1951 | 6 |
| 1952 | 3 |
| 1953 | 2 |
| 1954 | 2 |
| 1955 | 1 |
| 1959 | 3 |
| 1960 | 1 |
| 1963 | 2 |
| 1964 | 1 |
| 1965 | 1 |
| 1966 | 1 |
| 1967 | 1 |
14 with no year recorded