EASA AD 2021-0274-E
Engine — High Pressure Pump Driving Gear — Inspection / Replacement
Summary
EASA Airworthiness Directive 2021-0274-E is an emergency directive addressing inspection and replacement requirements for the high pressure pump (HPP) driving gear on Austro Engine GmbH E4 and E4P engines. These engines are commonly installed on Diamond Aircraft Industries models DA 40 NG, DA 42 NG, DA 42 M-NG, and DA 62 aeroplanes. The directive targets specific part number combinations of cylinder heads and HPP driving gears that may cause premature gear failure.
What Changed
This directive supersedes EASA AD 2021-0203R1 and introduces updated inspection and replacement procedures based on new findings about affected cylinder head and HPP driving gear combinations. It prohibits installation of certain HPP driving gears on engines with specific cylinder heads and refines the list of affected parts, incorporating Austro Engine Service Bulletin MSB-E4-036 requirements.
Why It Matters
The directive is critical for aviation professionals because it addresses a potential unsafe condition that could lead to engine in-flight shutdown and forced landing. Operators and maintenance organizations must ensure compliance to prevent gear failure, which could result in damage to the aircraft and risk to occupants. It also affects parts installation policies and maintenance planning for affected engine models.
What To Do
Operators must inspect and replace affected HPP driving gears before the next flight after 13 December 2021 if their engine has the specified cylinder head/HPP gear combination. Replacement deadlines vary by engine group and flight hours accumulated, with immediate action required for certain cases. Installation of affected parts is prohibited from the effective date, and a single ferry flight is allowed for twin-engine aircraft to reach maintenance facilities.
AI-generated summary from official EASA source document. Always verify against the original.