Writing about hypoxia in the December issue of Aviation Safety had me reminiscing about my days doling out high-altitude endorsements during a Part 135 training program. The Pilatus PC-12 was a great transition aircraft and boy, was it capable of rapid descents; flown close to the limit, we would regularly see 6-7000 fpm down and some impressive deck angles. It was great fun in the aircraft, but dealing with ATC was always a challenge. We had to file IFR to get into the flight levels, only to attempt to depart those flight levels as rapidly as possible.
Emergency descents are a useful maneuver even outside the flight levels. Smoke/fire/fumes or a medical emergency can justify an emergency descent and proper execution in time-sensitive situations can be lifesaving. Emergency descents are not something convenient to practice and in my experience are rarely brought up during flight reviews.
