A Rotax engine was delivered this year without two sets of parts in its propeller gearbox: the oil spray nozzle, and the M7 screws that hold the propeller shaft bearing in place. The parts had not been installed at the factory.
Rotax has issued an alert service bulletin, Europe has issued an emergency directive, and the FAA has issued an airworthiness directive. Which of them applies to a given aircraft depends on the engine model. For most amateur-built aircraft it is Rotax's bulletin, not the FAA's directive.
What the FAA ordered
AD 2026-16-11 took effect August 28, 2026. It requires a one-time visual inspection of the propeller gearbox to confirm that the oil spray nozzle assembly and the M7x16 hexagon screws are there.
The FAA issued the directive without first taking public comment. Without the nozzle and the screws, the propeller shaft bearing can move inside the gearbox. That can cause loss of the engine's oil in flight, which the FAA says could result in "engine in-flight shutdown or loss of control of the airplane." The agency also said it had no information on how quickly the problem develops.
An engine with fewer than 25 hours is inspected before further flight. An engine with 25 hours or more is inspected within five more flight hours. A gearbox found without the parts is replaced before further flight.
Only gearboxes on Rotax's list are affected. The directive points to the serial numbers in Rotax Alert Service Bulletin ASB-2026-001R00, dated June 22, 2026, both for gearboxes delivered on engines and for those sold as spares. It also bars anyone from installing a listed gearbox on any engine until it has been inspected.
Which engines the AD names
The directive names certified engines. Its applicability paragraph lists the Rotax 912 F2, F3 and F4; the 912 iSc2 Sport and iSc3 Sport; the 912 S2, S3 and S4; and the 914 F2, F3 and F4. It adds the 912 A series as installed in eight type-certificated aircraft, among them the Diamond DA20-A1 and the Katana.
The FAA counts 180 affected engines on U.S.-registered airplanes.
The engines most common in amateur-built and light-sport aircraft are not in that list. There is no 912 UL or 912 ULS in the applicability paragraph, and no 912 iS Sport, which is the engine in the Van's RV-12iS.
Engines the AD does not name
The parts were left out at the factory. The FAA's directive reaches the engines the FAA has authority over through their type certificates. The bulletin underneath it is Rotax's, and Rotax decides which serial numbers go on its list.
Van's Aircraft has addressed it for its own aircraft. On June 24, 2026, two days after Rotax issued the bulletin, Van's posted Rotax ASB 2026-001 to its service page for the RV-12iS, describing it as applying to Rotax 912 iS Sport engines with certain serial numbers.
For an owner of any 912 or 914, certified or not, the step is the same: get the current revision of ASB-2026-001 from Rotax, and check the gearbox and engine serial numbers against its lists. For a listed engine that the FAA's directive does not name, Rotax's bulletin is the document to follow.
The earlier Rotax gearbox matter is separate
A similar matter affected the 915 and 916 last winter. That was a separate fault: a collar nut left off the propeller shaft, covered by Rotax ASB-915 i-021R1 / ASB-916 i-009R1 of November 27, 2025, and by the FAA's AD 2026-04-02. The FAA said then that no engine it covered was on the U.S. registry. Both involve the propeller gearbox and parts that were not installed in production, and nothing else connects them. Each has its own bulletin and its own serial numbers.
What isn't known yet
Rotax's bulletin has been revised since the FAA wrote its directive; the directive cites the first issue, R00. Hangar Debrief has read the FAA's directive in full but has not read Rotax's bulletin itself, and so cannot say here which non-certified serial numbers are on its lists. The bulletin is the document to check.
Sources
All read on October 11, 2026.
- FAA, Airworthiness Directive 2026-16-11, BRP-Rotax engines and various aircraft, Federal Register, August 13, 2026, pages 52236 to 52239, Docket No. FAA-2026-7235. Effective August 28, 2026.
- FAA, Airworthiness Directive 2026-04-02, BRP-Rotax engines, Federal Register, March 4, 2026. Effective March 19, 2026.
- Van's Aircraft, service information for the RV-12iS, listing Rotax ASB 2026-001, posted June 24, 2026.
- Rotax Alert Service Bulletin ASB-2026-001, first issued June 22, 2026, from Rotax. Referenced, not reproduced.
Photo: Rotax 912 by Greg Goebel, used under the Creative Commons Attribution-ShareAlike 2.0 license, resized. The engine pictured is an illustration of the type and is not known to be affected.