More Engines Added to FAA's Aluminum Oil Watchlist
Published Date: 2/25/2025
Rule
Summary
If you own certain Austro Engine GmbH E4 or E4P engines, this new FAA rule updates which engines need regular oil checks for aluminum levels to keep them safe. It adds some engines to the list, removes others, and keeps the same fix rules from before. The changes kick in April 1, 2025, so get ready to keep your engines in top shape without surprises!
Analyzed Economic Effects
3 provisions identified: 0 benefits, 2 costs, 1 mixed.
Mandatory oil checks at short flight-hour intervals
If you own or operate an Austro Engine GmbH Model E4 or E4P engine listed in the service bulletin, you must perform repetitive engine oil analyses for aluminum content. The AD requires initial oil analysis within 15 flight hours (FH) for certain Group 1 and 3 engines or within 25 FH for certain Group 2 and 4 engines, and repeat analyses before exceeding 50 FH or 100 FH as specified; the AD is effective April 1, 2025. The FAA estimates the oil analysis costs $85 per engine and that 357 engines on U.S. aircraft are affected (total estimated immediate cost $30,345).
Risk of expensive part or engine replacements
If an oil analysis shows aluminum above the specified limit, you must replace pistons, piston rings, con-rods assembly, and crankcase or replace the engine core before further flight. The AD lists on-condition cost estimates per engine of about $7,741 for pistons/piston rings/con-rods assembly replacement, $10,516 for pistons/piston rings/con-rods plus crankcase replacement, and $18,499 for engine core replacement; completing those replacements also terminates the repetitive oil-analysis requirement.
Some engine serial numbers added or removed
The AD updates which Austro E4/E4P engine serial numbers are covered: it adds specific ESNs (listed in Table 2 of the service bulletin) and removes certain ESNs from the prior AD's applicability. These applicability changes take effect April 1, 2025 and determine whether an operator must follow the oil-analysis and replacement rules.
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