Tipsy Nipper T.66 Series 2, G-ATBW
Four of the six bolts that secured the wooden propeller to the engine worked loose causing all the bolts to fail and the propeller to detach from the aircraft in flight. The aircraft landed safely in a field. The investigation discovered that two of the bolts had not been wire locked and two others had been wire locked incorrectly. While the torque on the bolts had been checked within the recommended hourly maintenance interval, due to the low usage the aircraft had flown for almost two years without the torque having been checked.
Tipsy Nipper T66 Series 2, G-ATBW 08-11.pdf (390.14 kb)