Originally Posted by RAT 5
IMHO there ain't no rush in modern a/c (jets). There is enough onboard O2 for pax and crew to complete a rapid (emergency descent) into oxygen rich air just by using speed and speed brake to descend. Using gear, which you will need later in full working order, should not be necessary.
I fully agree, this is much overlooked in the training phase. The priority with decompression scenario is to get yourself and your colleague(s) on the flight deck on 100% O2. Once that is done, there is time for couple of deep breaths and then calmly execute the emergency descent. Even if pax don't get on O2 immediately, delaying descent for couple of seconds to get your thoughts together will make absolutely zero difference as far as their health is concerned.
As said by others, rate of descent in a modern jet with speedbrakes at Mmo/Vmo is more than sufficient to reach FL100 in couple of minutes. Some operators are now teaching even to initially maintan the current speed during emergency descent, perform a quick damage assessment (vibration, system parameters, etc.) and only then go for Vmo/Mmo if no damage and higher rate of descent is required.
Lowering the landing gear for emergency descent in a modern jet is only asking for trouble, especially if you can't get it up after finish with the manuever. Imagine crusing at FL100 after depressurization with gear down in ETOPS segment...