AD 2025-02-12Published 2025-02-25Effective 2025-04-01
Supersedes 2023-20-03
Austro Engine GmbH Engines
The FAA is superseding Airworthiness Directive (AD) 2023-20-03 for certain Austro Engine GmbH Model E4 and E4P engines.
1 AD superseded by this one retired · earliest 2023-11-06
AD 2023-20-03Published 2023-11-06Effective 2023-12-11
Austro Engine GmbH Engines
Requires repetitive engine oil analysis for aluminum content outside the acceptable limits and, if necessary, replacement of the pistons, piston rings, con-rods assembly, and crankcase or, as an alternative, replacement of the engine core.
Full official abstract
Airworthiness Directives; Austro Engine GmbH Engines
The FAA is adopting a new airworthiness directive (AD) for certain Austro Engine GmbH Model E4 and E4P engines. This AD is prompted by reports of piston failures and the determination that certain batches of pistons were manufactured with a dimensional deviation in the piston pin bore and piston diameter. This AD requires repetitive engine oil analysis for aluminum content outside the acceptable limits and, if necessary, replacement of the pistons, piston rings, con-rods assembly, and crankcase or, as an alternative, replacement of the engine core. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2023-24385, retrieved 2026-08-17 · checked against the live Federal Register record on 2026-10-02
Full official abstract
Airworthiness Directives; Austro Engine GmbH Engines
The FAA is superseding Airworthiness Directive (AD) 2023-20-03 for certain Austro Engine GmbH Model E4 and E4P engines. AD 2023-20-03 required repetitive engine oil analysis for aluminum content outside the acceptable limits and, if necessary, replacement of the pistons, piston rings, con-rods assembly, and crankcase or, as an alternative, replacement of the engine core. Since the FAA issued AD 2023-20-03, the manufacturer identified errors in the lists of affected engines and provided updated information, which prompted this AD. This AD retains the requirements of AD 2023-20-03, adds compliance times for additional affected engine serial numbers, and removes certain engine serial numbers from the applicability of the existing AD. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2025-03010, retrieved 2026-08-17 · checked against the live Federal Register record on 2026-10-02
