AD NUMBER: 2019-18-08

PRODUCT: All Engine Alliance (EA) GP7270 and GP7277 model turbofan engines.

ACTION: Final rule; request for comments.

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2019-16-04 for the products listed above.

AD 2019-16-04 required a visual inspection of the 1st-stage low-pressure compressor (LPC) rotor assembly, referred to after this as the “engine fan hub assembly,” for damage, a one-time eddy current inspection (ECI) of the engine fan hub blade slot bottom and blade slot front edge for cracks; and removal of parts if damage or defects are found. AD 2019-16-04 also required replacement of the engine fan hub blade lock assembly for certain GP7270 and GP7277 model turbofan engines.

This AD, for certain GP7270 and GP7277 model turbofan engines, reduces the compliance time for the initial ECI and requires repetitive ECIs of the engine fan hub blade slot bottom and blade slot front edge for cracks. This AD also retains the visual inspection requirements of the engine fan hub assembly for all GP7270 and GP7277 model turbofan engines.

This AD was prompted by an uncontained failure of the engine fan hub.

DATES: This AD is effective October 9, 2019. Comments must be received by November 8, 2019.

COST: The FAA estimates that this AD affects zero engines installed on airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

• ECI: 20 work-hours × $85 per hour = $1,700 per engine.
• Visual inspection: 1 work-hour × $85 per hour = $85 per engine
• Replace fan hub blade lock assembly: Labor: 25 work-hours × $85 per hour = $2,125. Parts: $28,000. Cost per airplane $30,125.

On-Condition Costs

• Replace engine fan hub assembly: 50 work-hours × $85 per hour = $4,250. Parts: $790,500. Cost per engine: $794,750

FMI: AD