Background: Task Force for Aviation Safety
The large number of incident reports in connection with Rotax engines led to the establishment of a special task force in 2023. EASA, national aviation authorities such as the LBA (Germany), BAZL (Switzerland), Austrocontrol (Austria) and the manufacturer Rotax itself work closely together in this task force. The aim is to systematically analyse the causes of malfunctions and develop preventive measures.
Rotax 912 engines are among the most widely used engines in general aviation worldwide. They are used in EASA-certified small aircraft as well as in a large number of ultralight and motorised glider models. In view of the large number of aircraft in the fleet, even individual faults have potentially far-reaching safety implications.
The Service Bulletin SB-912-079 R2
In November 2024, Rotax published the first version of Service Bulletin 912-079, which dealt with measures to prevent power loss and engine damage. Due to numerous responses, revision 2 was published in February 2025, specifying requirements for fuel quality, exhaust systems, carburettor preheating, cooling and ignition systems, among other things.
Important points are:
- Adaptation of the manuals by the aircraft manufacturers by February 2026 at the latest.
- Clear delineation of which documents apply to which aircraft types (installation manuals for type certification).
- Specification of inspection and maintenance steps that are mandatory as part of the 100-hour inspections or in the event of anomalies.
- Additional tests for engines with low running times (<400 hours), such as differential and crankcase pressure tests.
Obligations for manufacturers, operators and pilots
The bulletin is aimed equally at aircraft manufacturers (TC holders), operators and pilots. Manufacturers are obliged to adapt manuals and checklists accordingly. Operators and pilots, in turn, must adhere to the documents published by the manufacturer and implement changes immediately. Flight schools (ATOs) are obliged to integrate the requirements into their training documents so that trainee pilots and pilots-in-command can apply these procedures correctly.
Particular attention is drawn to the correct fuel selection (at least RON 95, often recommended RON 98) and the proper use of carburettor preheating. According to experience reports, errors in these areas are among the most frequent causes of power losses.
Maintenance requirements
Maintenance companies and certifying staff (Part-66 licences B1.2, B3 or L2) must observe the specifications for inspections and repairs. Typical focal points are
- Exhaust system: Check for unauthorised modifications, cracks or weld seams that could change the exhaust gas flow.
- Cooling: Checking compliance with temperature limits, especially in summer operation.
- Ignition system: Check the cable routing, coils and the Advanced Start Module.
- Carburettor preheating and airbox: Function test and visual inspection for leaks.
- Propeller adjustment: Ensure that the fixed or controllable pitch propellers are set in accordance with the manual.
Many measures overlap with the points of the 100h inspection that are prescribed anyway, but should be clearly documented in the logbook.
Reporting obligations in the event of malfunctions
The LBA pays particular attention to the timely reporting of safety-relevant incidents. Operators are obliged to submit incidents via the European ECCAIRS2 reporting portal. These reports are automatically forwarded to the responsible bodies such as the LBA, the manufacturer and, if applicable, Rotax. Rotax has also created its own online reporting tool, which has been available since May 2025.
The reports are a key component in improving safety: they make it possible to recognise patterns, trace chains of causes and, if necessary, issue airworthiness directives (ADs).
Outlook: Cooperation for greater security
Although the safety instructions are not directly legally binding, they are an important instrument for raising awareness. The close co-operation between authorities, manufacturers and operators illustrates that flight safety in general aviation must be considered in an increasingly international and networked manner.
For pilots and owners of aircraft with Rotax engines, this means increased attention to fuel quality, consistent maintenance and the conscientious implementation of service bulletins. This is the only way to prevent engine faults at an early stage and ensure the high reliability of Rotax engines in the long term.
Source references:
LBA