AD NUMBER: 2019-05-07

PRODUCT: Certain Honeywell International Inc. (Honeywell) TFE731-20 and TFE731-40 turbofan engines.

ACTION: Final Rule.

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2017-20-01 for the engines listed above.

AD 2017-20-01 required removing the affected fan disk and replacing it with a fan disk eligible for installation. Since we issued AD 2017-20-01, the FAA determined that some turbofan engine models were omitted from the applicability of AD 2017-20-01.

This AD adds turbofan engine models to the applicability and removes the Honeywell TFE731-20 turbofan engine model from the applicability.

This AD requires removal of affected fan disks and replacement with parts eligible for installation.

This AD was prompted by two fan disks found with surface rollovers in the dovetail slot area.

DATES: This AD is effective April 25, 2019.

COST: The FAA estimates that this AD affects 61 engines installed on airplanes of U.S. registry. Operators may incur the following costs in order to comply with this AD:

• Remove fan disk and send to Honeywell for inspection 8 work-hours × $85 per hour = $680 per engine.
• Install reworked or new fan disk 26 work-hours × $85 per hour = $2,210 per engine

The FAA estimates the following costs to do any necessary fan disk replacements that would be required based on the results of the inspection. The FAA estimates that six engines will need this replacement:

• Replace the non-serviceable disk with a new fan disk 1 work-hour × $85 per hour = $85. Parts: $50,000. Cost per engine: $50,085.

FMI: AD