EASA warns again about ethanol in Mogas

The GAfuels Blog is written by two private pilots concerned about the future availability of fuels for piston-engine aircraft: Dean Billing, Sisters, Ore., an expert on autogas and ethanol, and Kent Misegades, Cary, N.C., an aerospace engineer and aviation journalist.

Despite widespread concern over property damage caused by ethanol’s presence in fuels in the U.S., and direct links between ethanol production, rising food prices and unrest in the Middle East, Europe recently approved the use of up to 10% ethanol in automotive fuels. Given the widespread use of Mogas in Europe’s aviation community, EASA, the European Aviation Safety Agency, has issued a renewed warning titled SIB 2007-01R1, “Use of Automotive Gasoline (Mogas) containing Bio-Ethanol”, which can be found here.  This EASA Safety Information Bulletin contains the following:

The unauthorised use of fuel containing methanol or ethanol in aircraft can cause the following problems, potentially resulting in engine in-flight shut downs or fires, due to leakages:

  • Increased risk for vapour lock due to different volatility.
  • Incompatibility with several materials in the fuel system.
  • Phase separation into an alcohol-rich aqueous phase and an alcohol-poor hydrocarbon phase when the fuel is cooled (e.g. at high altitude) and not free of water.
  • Improper fuel quantity indication, regardless of the quantity of methanol and/ or ethanol, especially when capacitive fuel quantity gauging systems are used.

Given that, in Germany alone, some estimates put the use of Mogas at 50% of the total fuel consumed by piston-engine aircraft, the disappearance of ethanol-free fuel has the potential to seriously affect the safety and cost of General Aviation there as it has in North America.



    Property damage due to fuel ‘contamination’ is the tip of the iceberg.
    The mix of Jet A, Avgas and Mogas of unknown blends will eventually lead to inflight failures and death or injury. The consequence will be a reduction in the number of pilots and piston engined aircraft. Along with food shortages the population reduction will save the planet from ‘climate change’. The only safe path would appear Jet A for all.

  2. says

    Dennis, the EPA has just approved E15, 15% ethanol blend. Their ultimate goal is E85. Changing materials to be compatible with E10 is futile. Higher levels of ethanol will result in significant reductions in range and higher fuel consumption rates to deliver the same power. Higher levels of ethanol are non-starters for existing aircraft and engines.

  3. J Boisseau says

    I own a 1955 F-35 Bonanza and accidently used 100 gal mo-gas with 10% ethenal. lost 4 fuel tanks, 1 aux fuel pump, 1 eng driven fuel pump.

  4. Dennis Reiley says

    Which only shows that it is critical for the aviation industry to change the seals and other materials in aircraft fuel systems to those compatible with ethanol.

    They can do it voluntarily or they can wait until they are forced to do so because of safety; but it will happen.

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