Airworthiness Directive · Amendment 39-22562 · Austro Engine GmbH Engines
Austro Engine GmbH Engines
Superseded. A later AD replaced this one: AD 2025-02-12. Comply with the one in force.
This AD applies to Austro Engine GmbH Model E4 and E4P engines with a serial number listed in Tables 1, 2, 3, and 4 of Austro Engine GmbH Mandatory Service Bulletin No. MSB-E4-039/1, Revision 1, dated April 24, 2023 (MSB-E4-039/1).
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.
(1) For all affected engines, within the applicable compliance times specified in Table 1 to paragraph (g)(1) of this AD, perform an oil analysis in accordance with paragraph 2., Technical Details, Engine Oil Analysis of MSB-E4-039/1, and do not return the engine to service until the results of the oil analysis have been determined.
| Engine group | Compliance time | Interval |
|---|---|---|
| Group 1 and Group 3 | Within 15 flight hours (FHs) from the effective date of this AD | Before exceeding 50 FHs since last oil analysis. |
| Group 2 and Group 4 | Within 25 FHs from the effective date of this AD | Before exceeding 100 FHs since last oil analysis. |
(2) Thereafter, repeat the oil analysis required by paragraph (g)(1) of this AD before exceeding the applicable interval specified in Table 1 to paragraph (g)(1) of this AD.
(3) Following each repetitive oil analysis, the engine may be returned to service for no more than the applicable interval specified in Table 1 to paragraph (g)(1) of this AD, until receipt of the oil analysis result.
(4) If the result of any oil analysis required by paragraph (g)(1) of this AD indicates the aluminum content of the oil is greater than the limit specified in paragraph 2., Technical Details, Engine Oil Analysis, Table 5—Oil check analysis—Aluminum PPM allowable of MSB-E4-039/1, before further flight, replace the pistons, piston rings, con-rods assembly, and crankcase, or replace the engine core in accordance with paragraph 2., Technical Details, Engine core replacement; or Pistons, piston rings, crankcase and con-rod assy replacement; as applicable, of MSB-E4-039/1.
(5) For Group 3 and Group 4 engines, within the applicable compliance times specified in Table 2 to paragraph (g)(5) of this AD, replace the pistons, piston rings, and con-rods assembly, or replace the engine core in accordance with paragraph 2., Technical Details, Engine core replacement; or Pistons, piston rings and con-rod assy replacement, as applicable, of MSB-E4-039/1.
| Engine group | Compliance time |
|---|---|
| Group 3 | Before exceeding 900 FHs since new, or within 15 FHs after the effective date of this AD, whichever occurs later. |
| Group 4 | Before exceeding 1,000 FHs since new, or within 25 FHs after the effective date of this AD, whichever occurs later. |
Note 1 to paragraph (g)(5): FHs since new indicated in Table 2 to paragraph (g)(5) of this AD are FHs accumulated by the engine since first installation on an airplane or since last overhaul as of the effective date of this AD.
(1) Replacement of the pistons, piston rings, con-rods assembly, and crankcase, or replacement of the engine core, as specified in paragraph (g)(4) of this AD, constitutes terminating action for the repetitive oil analysis required by paragraph (g)(2) of this AD.
(2) Replacement of the pistons, piston rings, and con-rods assembly, or replacement of the engine core, as specified in paragraph (g)(5) of this AD, constitutes terminating action for the repetitive oil analysis required by paragraph (g)(2) of this AD.
(1) For the purpose of this AD, Group 1 engines are engines having a serial number (S/N) listed in Table 1 of MSB-E4-039/1.
(2) For the purpose of this AD, Group 2 engines are engines having an S/N listed in Table 2 of MSB-E4-039/1.
(3) For the purpose of this AD, Group 3 engines are engines having an S/N listed in Table 3 of MSB-E4-039/1.
(4) For the purpose of this AD, Group 4 engines are engines having an S/N listed in Table 4 of MSB-E4-039/1.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
