What is the normal descent rate for airliners? A few days ago I was on a flight from SFO to AUS (Airbus 320) and I was shocked by the steep angle of descent into AUS. I have been on over a hundred commercial flights but I've never experienced such a steep descent. I checked the flight on flightaware.com and noticed that the descent rate was 3,000 to 4,000 fpm. On other days the descent rate is closer to 2,500 fpm.

Flightaware data: My flight vs another flight.

Two questions about this:


What is considered a "normal" descent rate for the A320?
What could be the reason for the exceptionally steep descent compared to a normal flight?
There are a few possibilities, there's no way to know which is correct without more information:


There could have been an emergency on board. If someone is showing signs of a serious illness pilots will get the plane on the ground in a hurry to get the person medical attention as soon as they can. Or there could have been an issue with the airplane or a passenger, like someone very drunk and unruly in first class, say
As @falstro said it could have been a slam-dunk approach, where a controller directs airplanes to do steeper descents to solve sequencing issues. Pilots know if they say "unable" that they probably won't get another approach for awhile, so they'll accept a steep descent to get on the ground sooner
It could have been a request of the pilots for a non-emergency reason, like them trying to make up scheduling time, or to stay within fuel limits