EASA AD US-2021-05-51
SUPERSEDED BY FAA AD 2022-06-09
Summary
FAA Airworthiness Directive 2021-05-51 is a final rule addressing certain Pratt & Whitney PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engines. It requires inspections of 1st-stage low-pressure compressor (LPC) blades due to an in-flight blade failure that caused an engine fire on a PW4077 engine. The directive aims to prevent blade release, engine damage, and potential airplane damage.
What Changed
This new airworthiness directive mandates performing thermal acoustic image (TAI) inspections on specified 1st-stage LPC blades and removing any blades that fail inspection. It follows an emergency AD issued earlier and formalizes the inspection and removal requirements as an interim safety measure. The FAA anticipates further rulemaking actions on this issue.
Why It Matters
This directive is critical for aviation professionals because it addresses a serious safety risk involving LPC blade failure that can lead to engine fires and structural damage. Operators and maintenance organizations must ensure compliance to prevent in-flight engine failures and maintain airworthiness. Timely inspections and blade replacements are essential to uphold safety and regulatory compliance.
What To Do
Affected operators must perform the required TAI inspections on the 1st-stage LPC blades before further flight after March 24, 2021. Any blades found cracked must be removed and replaced. Operators should also submit comments to the FAA by April 23, 2021, if they have input on the directive.
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