That being said, obviously there was some serious safety issue, so kudos to the pilot for quickly and safely securing the aircraft
Once the aircraft is established in the descent, there is a bit of additional buffeting (light turbulence) and wind noise, but there is no highly unusual attitude involved. Initially, depending on how aggressively the pilot transitions from level flight to the descent, there can be a brief second of reduced or even zero G, but a smooth transition does not increase the total descent time by too much.
I have a colleague who was involved with the flight testing of the C-17 military cargo plane. That aircraft can safely deploy all four thrust reversers while in-flight to make a high angle tactical descent - it can hit in excess of 25,000 FPM. Supposedly everyone on the test flight was supposed to have been medically cleared for this flight, but one crew member had a lingering ear infection, and blew out both eardrums during the test.
So 3500ft/min is about 35 knots vertical speed. Not much compared to the horizontal speed, which is closer to 500 kn.
Ascent to cruise was around 1,000-2,000 ft/min.
There wasn't any feeling of falling at all. Also absent of any feeling of revitalization after a near-death experience, if that is in fact what is was or could have been.
Then back up just under the cloud layer, landed fine and then that was that.
Non-Precision means that you are using a simple ground-based navigation aid that does not provide vertical guidance, (a glide path indication) for example an NDB (Non-directional beacon) or VOR (VHF Omnidirectional Range) So, there are intermediate "step-down" fixes, that require you to maintain a certain minimum altitude until you reach a certain distance from the navaid. The route and altitude requirements (obstacle and terrain clearance) are selected by a well documented process called TERPS / FAA Order 8260.3F. (Edit, oops up to F now.)
There's always been debate among pilots about whether these approaches should be flow using a "Continuous Descent" method, where you select a descent rate to try to arrive at the altitude crossing restriction exactly before the next one comes into effect, or if you should descend rapidly to the altitude restriction, then level off until the next altitude restriction arrives, AKA "Dive and Drive."
There are pros and cons to each method and you can find well respected flight instructors that advocate for each. But a "Dive and Drive" approach can put you visually close to the ground when you are still pretty far from he airport. Really, modern GPS based RNAV approaches make the whole debate close to obsolete. Any podunk airport can get a satellite based precision approach with no significant investment in equipment, just a survey and some lighting improvements.
Only once we had levelled off were the flight crew able to inform us what had happened. Those intervening 6 or 8 minutes, however, were decidedly Type 3 fun.
https://globalnews.ca/news/2487158/breaking-vancouver-bound-...
https://www.rei.com/blog/climb/fun-scale
For me, an airplane depresurization event without structural damage would probably be a 1.5. Worrying/Stressing in the passenger seat isn't going to affect the outcome, so might as well sit back and enjoy.
General question: why is it that for such events, it is usually the airline name, or sometimes the flight number, that is mentioned first, and not the plane model? That would seem more relevant to me (not least considering Boeing's safety history).
I've listened to a lot of ATC recordings and there are many engine fires, bird strikes, and general malfunctions that never get reported on.
Here's a video of two pilots demonstrating an emergency descent in a simulator: https://www.youtube.com/watch?v=yHawjB2PzK0
