EASA AD US-2020-01-55
Engine - Interstage Seals - Replacement
Summary
The Federal Aviation Administration's Airworthiness Directive 2020-01-55 addresses certain General Electric Company GE90-110B1 and GE90-115B turbofan engines installed on Boeing 777-300ER aircraft. This directive mandates the removal from service of specific interstage seals, part numbers 2505M72P01 and 2448M33P01, due to a risk of uncontained high-pressure turbine failure. The directive aims to prevent engine damage and potential loss of the airplane caused by high-energy debris release.
What Changed
This new airworthiness directive requires operators to remove the affected interstage seals from specified GE90-110B1 and GE90-115B engines within five flight cycles. It formalizes and extends the requirements of the previously issued Emergency AD 2020-01-55, making the removal mandatory for all affected engines. The directive is considered an interim action pending further investigation into the root cause of the turbine failure.
Why It Matters
This directive is critical for aviation professionals because it addresses a serious safety risk involving uncontained turbine failure that can cause extensive engine and aircraft damage. Operators and maintenance organizations must comply promptly to ensure continued airworthiness and prevent in-flight engine failures. Compliance teams need to track affected engine serial numbers and part numbers to avoid operational disruptions and regulatory penalties.
What To Do
Affected operators must remove the interstage seal, part numbers 2505M72P01 or 2448M33P01, from the specified GE90-110B1 and GE90-115B engines within five flight cycles from the effective date of March 2, 2020. They should verify engine serial numbers against the list provided in the directive and coordinate with maintenance providers to schedule the removal. Additionally, stakeholders are invited to submit comments on the directive by March 30, 2020.
Your fleet's weekly compliance brief
AI-summarized regulatory changes, compliance deadlines, and action items — filtered to your aircraft, every Monday.
AI-generated summary from official EASA source document. Always verify against the original.