| AD Number | 74-16-05 | Status | Active |
| Effective Date | December 12, 1974 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-2033 |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Erickson Air-Crane |
| Model(s) | S-64A S-64E |
74-16-05 SIKORSKY AIRCRAFT: Amendment 39-1910 is amended by Amendment 39-2033. Applies to S-64A, S-64E, and S-56 helicopters certificated in all categories.
Compliance required as indicated.
To prevent fatigue failures of the main rotor head spindle lock nut, accomplish the following:
(a) Before the accumulation of 750 hours time in service on a main rotor head spindle lock nut, P/N S1510-23031-0, or within the next 25 hours time in service after the effective date of this AD, whichever occurs later, replace the affected lock nut with a serviceable part of the same part number and thereafter repeat replacement at intervals not to exceed 750 hours time in service.
(b) Before the accumulation of 10,500 hours time in service on a main rotor head spindle lock nut, P/N S1510-23031-1, or within the next 25 hours time in service after the effective date of this AD, whichever occurs later, replace the affected lock nut with a serviceable part of the same part number and thereafter repeat replacement at intervals not to exceed 10,500 hours time in service.
Amendment 39-1910 became effective August 15, 1974.
This amendment 39-2033 becomes effective December 12, 1974.