Action
Final rule.
Summary
We are superseding Airworthiness Directive (AD) 2017-20-01 for certain Honeywell International Inc. (Honeywell) TFE731-20 and TFE731- 40 turbofan engines. 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, we 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. We are issuing this AD to address the unsafe condition on these products.