B-b-b-but it 'plunged' and 'plummeted'...
Which implies that it was an uncontrolled response. Which, of course, it wasn't.
It does sound bad though, no? Depressurization event due to fault with the aircraft.
Do we know that it depressurised, and if so, to what degree. It's not impossible, with some failures, to actually get the aircraft down low before the cabin altitude becomes an issue. The masks may have been dropped manually, but the cabin would have had to exceed about 14,000' or so for it to happen automatically. You can't read too much into them being dropped.
Its just overall not well reported, however using the word rapid descent would be still accurate. 35k ft to 10k feet going straight from climb to rapid descent would be quite jarring.
Climb performance at FL350 wouldn't be anything like you experience at lower levels. The pitch attitude would probably be something in the order of 4º nose up. The descent would have only required the nose to be lowered by about 5-6º, and there's no reason for that to be done abruptly.
25k foot descent in 7 mins works out to be nearly 18m/s or 1.8G of constant descent. Especially as looking at FR24, they were literally ascending to cruise before this happened.
No. You misunderstand the term G. It's a measure of acceleration. The 18m/s is a velocity. There would have been very little acceleration involved in the descent, or even its entry, so basically the aircraft would have been at a normal 1g for the entire time.
Probably because it was a non-event. Pressurisation issue, pilots take the proper action to quickly descend to around FL100 and return to their home airport for a normal landing. Such pressurisation incidents happen quite regularly. The unusual circumstance with this one is that they actually made it to FL350 or so before experiencing the issue.
Most pressurisation events involved the controllers, or perhaps the bleeds (the air source) and not any form of breach. They happen, but I wouldn't call them common.
The rapid change from a climb to a descent would create momentary discomfort. A descent at 3500 feet per minute is within the parameters of what is considered normal.
Even the entry should have been smooth. The most notable part would probably have been speed brake extension, and the attendant vibration. 3,500 fpm was my normal in the 767.
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