| AD Number | 77-01-07 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-2807 |
| Product Type | ["Engine"] | Product Subtype | Not specified |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Pratt & Whitney Division |
| Model(s) | JT9D-20 JT9D-3A JT9D-7 JT9D-7A JT9D-7AH JT9D-7F JT9D-7H |
77-01-07 PRATT & WHITNEY AIRCRAFT: Amendment 39-2807. Applies to all Pratt & Whitney Aircraft JT9D-3A, -7, -7H, -7A, -7AH, -7F and -20 turbofan engines containing fifth stage turbine hubs, P/N 704705, 714905, 718905, 719205, and 726805.
Compliance required as indicated.
To prevent cracking and possible failure of fifth stage turbine hubs, the cyclic life limits on these parts have been reduced below the figures currently approved. Unless already accomplished, remove from service fifth stage turbine hubs prior to reaching the revised life limit listed below or within the next 25 cycles in service after the effective date of this AD, whichever is later.
Hub Part Number
Previous Life Limit (Cycles)
Revised Life Limit (Cycles)
704705
15,000
7,000
714905
15,000
6,000
718905
8,000
5,000
719205
8,000
5,000
726805
8,000
5,000
Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering & Manufacturing Branch, New England Region, may adjust the 25 cycle compliance interval to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator.
(NOTE: Pratt & Whitney Alert Service Bulletin No. 4671 pertains to this subject.)
This amendment becomes effective upon publication in the Federal Register.