Every Wessex pilot knew the risks of ground resonance in the old girl but more scary was doing full power pulls with the aircraft chained to the ground - you knew if any one of the chains let go, it was going to be brown underpants time.
That's exactly what happened to a mate at Culdrose in the late 1960s. A chain let go and the Wessex ended up thrashing itself around on its side and the pilot was rendered unconscious with severe head injuries even though he was of course strapped in and wearing a helmet. He never flew again due to his injuries.