Summary
We propose to supersede Airworthiness Directive (AD) 2017-20- 01, which applies to certain Honeywell International Inc. (Honeywell) TFE731-20 and TFE731-40 turbofan engines. AD 2017-20-01 requires 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 proposed AD would add these turbofan engine models to the applicability, remove the Honeywell TFE731-20 turbofan engine from the applicability, and prohibit installation of affected fan disks. We are proposing this AD to address the unsafe condition on these products.