SH1t happens!
Some years ago, a rather younger Genghis was working at a small outfit in England called Westland Helicopters. I wasn't involved in this (phew) but saw the aftermath. They had been doing IGE hover performance testing in a Merlin prototype. For conditions measurement they borrowed an airfield fire engine (a long wheelbase Range Rover I think) which drove in formation with the helo on the airfield and had been fitted with suitable instrumentation.
So picture the scene - 2 pilots in the helicopter, one heads in, the other watching horizon references. 2 Flight Test Engineers in the Range Rover, one watching instruments, the other watching the helicopter and driving. Nobody was watching the terrain.
So, very calmly, the helicopter hovered over the hedge at the end of the runway, and the two FTEs followed it through the hedge, over the main road, and through another hedge before stopping up to it's axles in a freshly ploughed field. The airfield fire section were I understand rather unhappy!
G