Methane was investigated as aviation fuel, and was found to be more problematic than Hydrogen - in fact, it's even less forgiving than hydrogen due to taking lo

Methane was investigated as aviation fuel, and was found to be more problematic than Hydrogen - in fact, it's even less forgiving than hydrogen due to taking longer to dissipate and having worse side effects in case of accidental tank rupture. In fact, the only viable use of Methane in aviation fuels was by 2007 considered to be... feedstock for Fischer-Tropsch chemistry, which also can make carbon-neutral syntin that will require no complete rebuilds of planes and engines.