Yet another 'Murphy' in the aviation game. In the 60's when the Whirlwind had been in service, in various marks, for many years, one of our instructors found that as the roror was engaged the beast started to shake itself to pieces. Hasty shut-down and much head shaking as to reasons. Nothing immediately obvious and it took much investigation and some sharp sighted-ness on someone's part to spot that the tail rotor was fitted the wrong way round !! Nobody had previously realised that it was a possibility. Thereafter, the pre flight required that the tail rotor be positioned in line with the pylon and a check that they matched aerodynamically.
Murphy is still there and waiting to indulge his/her warped sense of humour.
