Airworthiness Directive · Amendment 39-16886 · Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines
Pratt & Whitney Corp. (PW) JT9D-7R4H1 Turbofan Engines
Pratt & Whitney Corp (PW) JT9D-7R4H1 turbofan engines with a high-pressure compressor (HPC) shaft, part number (P/N) 808070 or 808071, installed.
We are adopting a new airworthiness directive (AD) for all PW JT9D-7R4H1 turbofan engines. This AD was prompted by reports of cracks in five high-pressure compressor (HPC) shafts. This AD requires removing certain HPC shafts before their certified life limits and establishes a new, lower life-limit for these parts. We are issuing this AD to correct the unsafe condition on these products.
For engines with an HPC shaft, P/N 808071, that has more than 4,500 CSN on the effective date of this AD, remove the HPC shaft from service within 500 cycles-in-service (CIS) after the effective date of the AD or at piece-part exposure, whichever occurs first.
For engines with an HPC shaft, P/N 808071, that has 4,500 or fewer CSN on the effective date of this AD, remove the HPC shaft from service before exceeding 5,000 CSN.
For engines with an HPC shaft, P/N 808070, remove the HPC shaft, P/N 808070, from service before exceeding 1,200 CSN.
(1) After the effective date of this AD, do not install or reinstall into any engine any HPC shaft removed in accordance with paragraphs (f), (g), or (h) of this AD.
(2) After the effective date of this AD, do not install or reinstall into any JT9D-7R4H1 engine:
(i) Any HPC shaft, P/N 808071, that is at piece-part exposure and exceeds the new lower life limit of 5,000 CSN, or
(ii) Any HPC shaft, P/N 808070, that is at piece-part exposure and exceeds the new lower life limit of 1,200 CSN.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
