[TheOtherDave]

I'm sure they'll reconsider as soon as someone develops jet engines capable of mach 2.2 that don't burn fossil fuels. In the meantime, since speed is their goal, they don't have much choice.

[wbl]

And doesn't spew a giant plume of radioactive gas while irradiating the passengers.

[reaperducer]

That's extra on United.

[robotresearcher]

United could burn luggage for fuel. They're gonna lose it anyway.

[andygates]

If the thing needs to burn go-juice, give it green go-juice. Isn't biofuel-derived avgas a thing yet? Startup idea...