Looking over the airport in preparation to land, we were startled by a peculiar white shape like a giant piece of pie covering half the paved tie-down area. Strange, then suddenly obvious. The white was emanating from a large propane tank. That’s right, several hundred cubic feet of pressurized explosive gas was venting across the pad between lines of parked planes (all containing fuel) and spreading out right below us. Granted, propane is a heavy gas, but a 2-33 is heavier.

Being not much more than a thousand feet up, our options at that point were few, but removing ourselves from the apex of an imminent fireball was job one. I had the student glide directly away as far as we could before turning back, then fly a straight-in approach to a spot landing in the corner of the airport furthest from harm’s way. Ideal training opportunity.

Propane is naturally oderless, and manufacturers add a foul smelling chemical so people can detect leaks. On late final that stench was thick in the air. Unbeknownst to us, by then the entire neighborhood was being evacuated and now fire trucks were pulling in to spray everything with water and remove flammable residues! Parked clear of the runway, we just stayed in the cockpit awhile, content to watch from three thousand feet shy of the action with our trusty bird’s canopy between us and the sirens – whence a violent pressure wave still might rush forth at any moment. Got a cigarette?

Later, someone on the scene who knew such things opined that if the vapor had ignited beneath us our time atop the cataclysm would have been short; a second later we’d have been deep inside it.

The guy who knocked the valve off that tank? Ass and elbows as some folks like to say, at Olympian speed despite big heavy workboots. No one knows if he’s stopped running yet.