1000fpm at FL100 is much less uncomfortable than 1000fpm at 3000ft – because the pressure changes a lot faster when you are lower.
Lots of people have problems with fast descents. My son could not do it, and I think he solved it with chewing gum, because swallowing equalises the pressure a lot better than doing nothing.
IME, if someone has blocked tubes then the pain will just got worse and worse and the only solution is to immediately stop the descent and wait for them to sort it. And tell ATC, if they want to know…
1000fpm at FL100 is much less uncomfortable than 1000fpm at 3000ft – because the pressure changes a lot faster when you are lower.
10000’ to 9000’ is a 4.7% change in pressure….3000’ to 2000’ is a 3.4% change….shouldn’t be a noticeable difference in (dis)comfort….it’s not like scuba diving!
I’ve been doing some fast descents as a result of airspace considerations but because they’re only from 4500 to 2500 ft (total) I haven’t noticed any issue. Along those lines, I have no idea what the physiological situation might be for for a friend who descends at 25,000 ft/minute as part of his display (straight down). I should ask him – maybe the discomfort is small enough in relation to the G at the bottom that he doesn’t notice it!
10,000 feet to 9,000 -3.7% change
3000 feet to 2000 -3.6% change
(using tables on http://www.engineeringtoolbox.com/air-altitude-pressure-d_462.html)
But then the absolute pressure change remains bigger so e.g. if your eustachian tube is completely blocked, the same maneuver lower down is going to create a bigger pressure differential and hurt a whole lot more.
My memory of diving procedure: Hold nose and blow when descending. Do so BEFORE you feel any discomfort. Swallow when ascending. If you have a nasal infection, descending can force virus/bacteria into the inner ear, infecting that area. If you’re really unlucky, it might get into the brain area. Diving you have an option to stop descent and surface.. Flying you can only slow descent.
That would be for snorkelling. In scuba diving, you continue to breathe normally the whole time (and must not stop).
For me it’s just fine. Even when diving I can rapidly dive to 10 meters. For some passengers – not.
Diving down to 10 metres is just fine. Ascending is where the problems lie.
Diving down to 10 metres is just fine. Ascending is where the problems lie.
It’s true that it is possible to tear your lungs by taking a deep breath at 10m and then surfacing without exhaling, but in terms of the eustachian tubes working (which is the main issue in flying) this is fine because they normally remain open from the “inside to outside” direction. This is why a rapid climb doesn’t affect most people. There is something about the geometry of the tubes which makes them much more likely to get blocked in the other direction (outside to inside) and this is why people have problems with rapid descents.
Disclaimer: I got only to the BSAC “F” test before dropping out, because I didn’t want to do the next stage which was open sea diving with a 10mm wetsuit 
Just thinking back to this weekend, I was demonstrating a side slip to a non pilot, showing him the easiest way to descend at a high rate of descent without gaining speed and fully established, only just managed to get 1700fpm descent on the variometer. I can just imagine flying at FL180, crossing the controls to get the slip started and holding it that way for 6 – 7 minutes……
