Fuel Pumps May Cause Engine Flooding, Fuel Leaks Due To Overpressure

The FAA has issued a Special Airworthiness Information Bulletin (SAIB) for certain part number fuel pumps installed on, but not limited to, Rotax 912 series aircraft engines. The pumps cause a possible unsafe condition on special light sport category aircraft (SLSA), experimental light sport aircraft (ELSA), and experimental amateur-built aircraft with the engines installed.

In some cases, if the input pressure to the mechanical fuel pump is high (e.g., due to an electric fuel pump upstream), the output pressure from the mechanical fuel pump could be excessive. This high fuel pressure may cause the engine to malfunction from flooding and/or cause fuel leakage. The fuel pumps affected by this issue are 892230, 892232, 892540 (standard version), and 892235, 892236, 892545 (version including flexible line). Pumps with part numbers 892542 and 892546 are not affected.

The engines likely to be affected by this issue are:

• 912A S/Ns 4,410.684 through 4,410.727
• 912F S/Ns 4,412.913 through S/Ns 4,412.925
• 912S S/Ns 4,923.282 through 4,923.461
• 912UL S/Ns 4,407.646 through 4,408.361
• 912ULS S/Ns 5,646.084 through 5,648.164
• 912ULSFR S/Ns 4,430.267 through 4,430.500 and S/Ns 6,374.028 through 6,374.054

  
  Rotax 912ULS

The FAA says ff your aircraft is affected by this issue, replacement of the fuel pump part numbers listed above is recommended following ROTAX Service Bulletins SB-912-053 and SB-912-053UL.

The FAA says it is taking airworthiness directive action to address this issue on the type-certificated aircraft and engines.

FMI: www.faa.gov