[doorgunner69]

Those hot air balloons used to come over my house in N San Diego all the time, sometimes quite low. The sound of that big blow torch suddenly blasting away after dead silence used to scare the bejeesus out of me. Watching that blaster was just as bad.

No way would I get into something that required an onbaord blast furnace to stay aloft.

[DooDahhhh]

I got on one in France and was off in 30 seconds!

[Secret Agent Man]

Jet engines are onboard blast furnaces. Not handheld but they burn quite hot and have been known to fail under certain conditions. Final flight of the last Concorde comes to mind.