OXYGEN MASKS - DON
OXYGEN REGULATORS - Set to 100%
CREW COMMUNICATIONS - ESTABLISH
PRESSURIZATION MODE SELECTOR - MAN AC/MAN
OUTFLOW VALVE SWITCH - CLOSE
Hold in CLOSE until outflow Valve indicates fully closed
If Pressurization is Not Controllable
PASSENGER SIGNS - ON
PASSENGER OXYGEN SWITCH - ON
EMERGENCY DESCENT - ANNOUNCE
The pilot flying will advise the cabin crew, on PA system, of impending rapid descent. The pilot monitoring will advise ATC and obtain area altimeter setting.
PASSENGERS SIGN - ON
DESCENT - INITIATE
I do giggle a little at the thought of a door flying off, the air rushing out of the cabin, and the pilots responding by switching the seatbelt light on.
The plane was only at 16,000 feet when it lost its door and according to [2] you've got 20-30 minutes of 'useful consciousness' at such an altitude, even without your oxygen mask on. So there was no need for an abrupt dive.
[1] https://www.theairlinepilots.com/forumarchive/b737/b737memor... [2] https://skybrary.aero/articles/time-useful-consciousness
Edit: Re-reading, it was more like 16K feet when it popped, 10K is what ATC assigned them when requested. Still low enough not to be a critical emergency. Some people absolutely will get altitude sickness at that level, but it's likely to be mild. Many people climb mountains much taller.
Better to climb for a bit more as you get your oxygen mask on than to try to descend immediately and make some problem worse.
We know it was a door plug blowing out, but in the past it has been entire major sections of the airframe ripping off, in which case sudden extra stresses are not what you want.
Pilots can't look at the rear view mirror, and see the whole plane. Accident reports on engine malfunctions routinely mention that someone had to check their appearance through the passenger window, and relay that to the pilots. In case of a blast so severe that the door flies off, it is safer to assume the worst. Say, that part of the plane disintegrated because of sudden collision. In such conditions, indications on what works and what doesn't are probably really messy and unreliable, and there can be not enough means to control the plane properly. Lower the nose too much, and you might not be able to pull it up any more.
Pilots probably did checklists with one eye on the instruments to check that they were not losing speed, that angles were correct, autopilot inputs resulted in stable flying, and so on, and deduced that everything still worked. By that time, they were probably informed that the plane was seemingly intact, although with a hole in its side.
Not really. The cockpit door was blown open, and the pilot's headsets were blown off. It was a pretty chaotic event, and when you are flying an airplane, you definitely don't want to figuratively "jerk the wheel" - you remain calm and start running checklists.
> Both flight crew said they immediately donned their oxygen masks. They added that the flight deck door was blown open and that it was very noisy and difficult to communicate.
> The flight crew immediately contacted air traffic control (ATC), declared an emergency, and requested a lower altitude. The flight was assigned 10,000 ft. The captain said he then requested the rapid decompression checklist, and the FO executed the required checklist from the Quick Reference Handbook (QRH). As the FO completed the checklist, the captain flew the airplane as they coordinated with ATC to return to the PDX airport. The flight landed on runway 28L without further incident and taxied to the gate.
So in this particular instance, when the depressurisation happened at a comparatively low altitude, the pilots did get ATC clearance before descending.
Sure, you are ~allowed~ to begin an immediate descent in an emergency, but it is not a good idea considering from the pilot's perspective, the bang is most likely an engine going out and altitude is always your friend in this condition.
> You can't leave your assigned altitude/trajectory without coordinating with ATC.
They didn't not say it was advisable, but heavily implied it was required.
In an emergency, caring about ATC is literally your lowest priority, in every case. It is ATC's job to notice a plane no longer under their control and route other aircraft safely around it. Your entire job is to do everything you can to prevent the death of anyone onboard, and playing ham radio is rarely the best way to do that.
Looking at the track, they descend to 10000' until they start their downwind to base turn. Once they start that turn, they get a lower altitude (looks like 7000') until they are established on final and can fly an approach.