Straight Alcohol Fuels for General Aviation Aircraft

The FAA Technical Center has evaluated straight methanol and ethanol fuels using an aircraft fuel system and engine which were installed on a dynamometer. The results of this program identified the conditions which should be used for hot fuel certification. Stoichiometric air-to-fuel ratios were identified as the most likely to result in either detonation or pre-ignition, and some material compatibility and operational problems were noted. The addition of small amounts of denaturing agents did not adversely affect the vapor lock behavior of the fuels.

Straight methyl-tertiary-butyl ether was also evaluated. This material's high octane rating, moderate volatility, and relatively high energy density make it an attractive candidate when compared against either ethanol or methanol.