Originally Posted by
Ascend Charlie
13 August 1981, Williamtown NSW. A UH-1B Huey was undergoing a test flight to try to determine a problem from a few days prior. For an unknown reason, the cable that operates the T/R pitch change came off its pulley, and wrapped around the T/R drive shaft - in D and H models, this cable was not near the driveshaft.
The T/R was pulled to an extreme pitch angle, huge yaw, the blade flapped so far it contacted the pylon and a piece of one blade broke off. The imbalance was so bad, the whole 90 deg gearbox and remaining blades departed the scene.
Massive yaw, and big nose down from losing 90 lbs from 30' back. The disc stayed level, however, so with the big change in fuselage attitude, there was a big mast bump, the main rotor separated and on its way out, sliced through the left side of the cabin (and the test pilot), removed the tailboom as well, and the remains fell 1500' inverted to the ground, loss of four lives.
The original problem was never solved, and I consider myself fortunate that I was the last person to fly that machine and survive.
AC, you are a lucky individual. Recollection is hazy, but IIRC, ARDU was looking at an issue on that aircraft, had you guys had an anomaly on the prior flights? I was in ASI at the time and I recall that the bolts on the shaft picked up the slack in the control cable, and wound on full input, and as you say, the flapping did the rest of the harm. It was a bad year or two for RW ops, with the midair, the CFIT in SA, and the CFIT into the reservoir. I was dragged into the midair investigation.