Airworthiness Directive · Amendment 39-19643 · Reciprocating engine cylinder section
BRP-Rotax GmbH & Co KG Engines
This AD applies to:
(1) BRP-Rotax GmbH & Co KG (Rotax) 912 F2, 912 F3, and 912 F4 engines, with serial number (S/N) 4 413 066 to 4 413 067, inclusive; and S/N 4 413 101 to 4 413 111, inclusive;
(2) Rotax 912 S2, 912 S3, and 912 S4 engines, with S/Ns 9 563 826 to 9 563 849, inclusive; S/Ns 9 564 301 to 9 564 508, inclusive; and S/N 9 564 510 to 9 564 534, inclusive;
(3) Rotax 914 F2, 914 F3, and 914 F4 engines, with S/Ns 4 421 581 to 4 421 597, inclusive; and S/N 4 421 701 to 4 421 833, inclusive; and
(4) Rotax 912 F2, 912 F3, 912 F4, 912 S2, 912 S3, 912 S4, 914 F2, 914 F3, and 914 F4 engines (all S/Ns) on which a valve push-rod assembly has been replaced with one manufactured between June 8, 2016, and October 2, 2017.
We are adopting a new airworthiness directive (AD) for certain BRP-Rotax GmbH & Co KG (Rotax) 912 and 914 model engines. This AD was prompted by power loss and engine revolutions per minute (RPM) drop on certain Rotax 912 and 914 model engines due to a quality control deficiency in the manufacturing process of certain valve push-rod assemblies resulting in partial wear on the rocker arm ball socket and possible malfunction of the valve. This AD requires one-time inspection and, depending on the findings, replacement of the affected parts with parts eligible for installation. We are issuing this AD to address the unsafe condition on these products.
(1) Visually inspect the push-rod ball sockets of each valve push-rod assembly in accordance with the Accomplishment Instructions, paragraph 3.1.2, of BRP-Rotax Service Bulletin (SB) SB-912 i-008 R1/SB-912-070 R1/SB-914-052 R1 (single document), Revision 1, dated October 12, 2017, and within the following compliance times.
(i) For engines with 160 engine flight hours (FHs) or fewer since new, inspect before exceeding 170 FHs since new, or within three months after the effective date of this AD, whichever occurs first.
(ii) For engines with greater than 160 engine FHs since new, inspect within 10 FHs, or three months after the effective date of this AD, whichever occurs first.
(2) If the inspection required by paragraph (g)(1) of this AD finds a black surface color on a valve push-rod assembly, part number (P/N) 854861, then before further flight, remove the valve push-rod assembly and the left and right rocker arm ball sockets, P/Ns 854383 and 854393, from service, and replace with parts eligible for installation.
After the effective date of this AD, do not install a valve push-rod assembly, P/N 854861, that was manufactured between June 8, 2016, and October 2, 2017, or that exhibits a black surface color on the push-rod rocker arm ball sockets, on any engine.
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.
