Well in this case it didn't burn to the ground but it was pretty close. Before I go on I must say that things were differant in NZ then and everything, everywere was a bit carefree in the 70's.
I will never forget when one of our pilots was self refueling, on a farm site, in a 300C with the engine running. His loader was on the way in the Holden so he was by himself. We had a small tank trailer that went from site to site towed by the ute.
It had a hand pump and a long hose so that it was well away from the helicopter.
My pal took the hose out to the helicopter and jammed the valve open with the tank cap then went back to the tanker to begin pumping. Unfortuneatly the tank wasn't as empty as he thought and it overflowed quickly filling the drip pan and spilling onto the exhaust. The reaction back at the tanker was to rip the hose away from the helicopter this was accomplished but unfortunately the cap flew away with the filler. Meanwhile the fire heated up the drip pan and the tank, expanding the fuel inside which helped to feed the fire. The first task was to plug the flow but precioius seconds were wasted trying to locate the tank cap in the surrounding grass. Once recovered our pilot, whose helicopter was his livelihood, bravely dashed into the flames and after a little toasting stopped the flow. Then the small extinguisher in the helicopter was used to put out the fire.
It was quite a save, resulting in a sagging panel on the right rear side of the canopy and general sooting around the tank and support. The helicopter was flown back to Hamilton and after a new plastic panel installed, went back to work.
Good lessen and something you would only do once... hopefully never.