To: heedm and Hookherder
It was my contention that the drive shafts were the weakest link and would fail if enough torsion were applied. During shut down the rotorbrake could bring the rotor to a stop in just a few seconds with significant heat build up and rejection but in this case the kinetic energy was decreasing at a constant rate so that any torsion applied to the shafts would also be constantly decreasing. However in the condition I described there would be two or three T-700 engines or the RR replacement engines driving the rotor and the accessory gearbox and there would be an even greater heat build up and more heat to be rejected causing the brake to clamp even harder. I believe there is a pressure release system that would allow the expanding fluid to vent but I believe by that time the shafts would have failed or possibly there would also be a fire.
Regarding the CH-47 quill shaft failure the EH-101 has redundant shafts to cater for a failure of one shaft. Regarding the change to the rotorbrake I believe that was a change in the electrical circuitry and not the relocation of the brake to the transmission. I must also state that my statements above were based on knowledge obtained in or around 1987 when the system was being designed and therefore my question relates to my findings in the FMEA.
[ 14 February 2002: Message edited by: Lu Zuckerman ]</p>