Airworthiness Directive · Amendment 39-18384 · Engine Alliance Turbofan Engines
Engine Alliance Turbofan Engines
This AD applies to Engine Alliance (EA) GP7270 turbofan engines with a high-pressure compressor (HPC) cone shaft, part number 382-100-907-0, installed.
We are adopting a new airworthiness directive (AD) for certain Engine Alliance (EA) GP7270 turbofan engines. This AD was prompted by the manufacturer informing us that the inspection criteria and repair procedures in the maintenance manual for aft bolt holes of the high- pressure compressor (HPC) cone shaft on the affected engines is incorrect. This AD requires inspection of the HPC cone shaft and repair of affected parts, if needed. We are issuing this AD to prevent failure of the HPC cone shaft, which could lead to uncontained engine failure and damage to the airplane.
(1) For HPC cone shafts with serial numbers listed in EA Service Bulletin (SB) No. EAGP7-72-330, dated July 21, 2015, inspect the inner diameter of the HPC cone shaft aft bolt holes for nicks, dents, pits, and scratches before accumulating 9,000 cycles since new (CSN). Do not reinstall the HPC cone shaft if the aft bolt hole has any nicks, dents, pits, or scratches that are greater than 0.002 inch in depth.
(2) For HPC cone shafts with serial numbers listed in EA SB No. EAGP7-72-329, dated July 21, 2015, shot peen the HPC cone shaft aft bolt holes before accumulating 9,000 CSN. Use paragraph 1 of the Accomplishment Instructions in EA SB No. EAGP7-72-329 to do the shot peening.
After the effective date of this AD, do not install an HPC cone shaft on any engine with the following:
(1) any nicks, dents, pits, or scratches in an HPC cone shaft aft bolt hole that is greater than 0.002 inch in depth; or
(2) any repair of an HPC cone shaft aft bolt hole that did not include shot peening.
