Descendent with jumpers in Safety and Training March 4, 2018 I have wondered the same thing - as in the original poster's question. It is obvious that this question does not present itself above the arming altitude of your AAD device 1000 feet....1200 feet uh...1400 feet....what ever the device arms at. But, his question is still lurking. BELOW the arming altitude how fast must the airplane descend for your AAD to fire? So, distilling the math (in my head) and seeing that most (OK not all) of the devices are arming at 78 miles per hour descent rate...wow!- the airplane would have to almost be "standing on it's head" to achieve a 78 mph descent rate. At that point, and at that altitude (below 1200 feet for example) the pilot better pull off some miracle to recover from a 78 mph descent rate. A rate I would compare to being in a helluva dive. Tell me if I'm wrong here, but it is my conclusion that below the 1200 foot or 1000 foot AGL altitude an airplane would be in a "ready to crash" mode to have a 78 mph descent rate. So, I am not inclined to worry about an AAD fire below 1000 feet; even if the pilot is descending so fast as to float me to the ceiling! At 1000 feet and below, that would (as Wendy more or less said) be an airplane in big trouble.