National data collection and results
In summer 2024, the BAT-AG conducted a nationwide survey of aviation clubs to investigate further cases and gain a more accurate picture of the problems. The almost 75 cases reported showed that the previous recommendations are largely correct and sensible. At the same time, additional technical causes were identified, which were integrated by the engine manufacturer Rotax into the Service Bulletin SB 912-097R1. This bulletin was published in November and revised shortly afterwards to provide pilots and flight instructors with updated recommendations for action.
BAT-AG has summarised the most important measures for the operation of Rotax engines in a comprehensive list. These recommendations are intended to help avoid power losses and increase the operational safety of the engines.
Detailed recommendations for safe operation
The following is a detailed summary of the recommendations, supplemented by practical tips:
Correct procedures for starting and switching off: Starting, warming up and stopping the engine should always be carried out in accordance with the manual instructions to prevent long-term damage.he technology should always be regarded as a supporting tool and not as the sole solution.
Choosing the right fuelThe choice of a fuel-specific product with the correct octane rating is crucial. It is strongly recommended to use only high quality and authorised fuel. This minimises the risk of knocking or ignition problems.
Avoidance of fuel contaminationContamination such as dirt particles, water or diesel residues can cause serious damage. Regular inspections and the consistent use of fuel filters are crucial here.
Compliance with temperature limitsAll relevant temperature parameters such as cylinder head, exhaust gas, oil and coolant temperature should be constantly monitored. Exceeding these values can lead to engine failure.
Optimisation of coolingThe right choice of airspeed and climb rate is essential to prevent the engine from overheating.
Observe the knocking limitsDepending on the aircraft application (e.g. training or towing) and the ambient conditions, the engine knock limits must be strictly adhered to.
Limitation of performance timesPowerful settings should be limited in time, especially when temperature limits are reached. This is crucial for the longevity of the engine.
Monitoring of additional measured valuesBoost pressure, petrol pressure, fuel flow and ambient conditions (e.g. temperature, air pressure) must be checked regularly. Early detection of deviations can prevent critical situations.
Propeller adjustmentProper procedure is required for variable pitch propellers in order to avoid unnecessary stress on the engine.
Carburettor preheating: Using the carburettor preheating system in a way that is adapted to the situation reduces the risk of carburettor icing, especially in damp or cold weather.
Maintenance and inspectionsRegular checks of oil and coolant levels as well as the cooling system are essential. This includes inspections of air intakes and radiators.
Avoidance of cold engine operationUnnecessary take-offs with a cold engine and short flights should be avoided. The engine should be brought up to minimum temperature before operation.
Achieving optimum oil temperaturesThe engine should reach an oil temperature of at least 100 °C once on each flight day in order to avoid condensation in the engine. At the same time, continuous operation above 110 °C should be avoided.
Source references:
DAEC
