Why be afraid of them? The fuel they leak everywhere is barely flammable, they only carry about a gallon of nitric acid to make it flammable, and the triethylborane they use to reignite a stalled engine may burst into hot green flame the instant it touches air, but it can be put out by dunking it in water. Yes, it will reignite again the moment you take whatever part it got on out of the water, but you can gradually let it burn off your asbestos suit that way. The only person ever hurt during a triethylborane fill-up wasn’t burned. He was knocked off the plane by a nervous fireman who was too quick with his hose, and broke his arm in the fall.