To: polehog
Hello "Tinkerbell" The failure that keeps me on my toe's is the input freewheel failure!!!!!
This happened on an Italian HH-53. From the time the pilot heard the noise it took twenty-two seconds for him to autorotate to the water.
When they opened the gearbox at Agusta they found that the left-hand FW unit had suffered a catastrophic failure that prevented the FW unit from Free Wheeling. The rotor system kept the transmission rotating and the energy back driving the frozen free wheel unit caused the metal parts to abrade, melt, and generally deform. The engine was also effected causing it to suffer severe damage. All of this in 22 seconds. It was however survivable.
