| AD Number | 57-08-01 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Scotts-Bell 47 Inc |
| Model(s) | 47 47B 47B3 47D 47D1 47E 47G 47G-2 47G-2A 47G-2A-1 47G-3 47G-3B 47G-3B-1 47G-3B-2 47G-3B-2A 47G-4 47G-4A 47G-5 47G-5A 47H-1 47J 47J-2 47J-2A 47K |
57-08-01 BELL: Applies to All 47 Series Helicopters With Tail Rotor Drive Shafts, P/N 47-644-115-1, 47-644-126-3, 47-644-172-3, 47-644-177-1, 47-644-179-7, 47-644-180-1, 47-644- 186-1, 47-644-187-1, 47-644-187-5, and 46-644-214-1, Having Less Than 100 Hours Service Time and All Spares of These Part Numbers.
Compliance required as indicated.
Due to suspected defective materials, the listed tail rotor drive shafts must be inspected for evidence of longitudinal cracks, as follows:
1. Inspect all spare shafts by magnaflux methods immediately.
2. Shafts installed on helicopters and having less than 100 hours service time must be thoroughly cleaned and inspected daily with at least a 10-power magnifying glass, and inspected by magnaflux methods not later than the next 10 flying hours. The daily inspections may be discontinued upon completion of the magnaflux inspection.
3. Spare shafts and helicopters delivered from Bell after April 15, 1957, have these inspections accomplished and may be identified by a double interlocking magnaflux stamp in approximately the centers of the shafts.
(This AD covers the same inspections required by CAA telegraphic instructions, dated April 12 and 17, 1957.)