It’s an unusual question, but it isn’t. And I’m sure that somewhere, someone actually keeps track of this sort of stuff. It just doesn’t happen to be me. I’ve been asked this several times, and the question came to mind the other day when I had to declare an emergency.
First of all, one has to define what an emergency is. My company manual says that a flight emergency is “any situation, such as a malfunction of the aircraft, that requires immediate decision and action for the safety of flight…[and] requires special procedures to be taken beyond those normally utilized in flight operations.” Note that none of this includes various other emergencies, such as medical emergencies. Basically, what it says, is that…well, it’s so clearly written that it’s pretty obvious what it says.
Still, there is room for interpretation. For instance, we would all probably agree that an issue with a failed elevator would constitute an emergency, which would justify declaring the same. What about a flap failure—specifically, one in which the flaps simply failed to deploy? This was a not-uncommon issue on the CRJ for several years. If flaps fail to move, is that really an emergency? It depends on your definition. Some operations will dictate that if a flight control of any form is involved, then it is an emergency, no matter how minor or severe the situation. The no-flap landing speed on the CRJ is 172 knots indicated. The max groundspeed for the tires is 182 knots. If this scenario were to occur at a high- elevation landing, those two numbers could wind up eyeball-to-eyeball with each other. Besides, 172 knots on final is fast–real fast. Almost 200-miles-an-hour fast. That’s approaching space-shuttle-on-final fast.
But when it comes to “common” emergencies, I’m not sure that there really is a one-sized-fits-all approach. At least, there doesn’t appear to be one for me. I’ve had the flap failure. I’ve had gear issues (this, to me, is the ideal emergency if there is one). I once had a hydraulic failure that forced a diversion. One flight required an engine to be shut down because of improper maintenance done on the airplane after a bird strike the day before. My most recent one was a spoiler that did an uncommanded deployment in flight. An uncontrollable fuel transfer system once caused two emergencies in one day. I used to joke that the tower would just declare an emergency on my behalf every time I took off.
As you can see, there really isn’t a pattern, and that is a testament to how well airplanes are designed and built these days. The redundancy alone is a lifesaver. In fact, sometimes, a redundant system can save the day automatically, and the crew doesn’t even know there was a problem until the airplane says, “Hey, I had this issue, but chill, because I already fixed it.” If I had to pin down the most common issue, it wouldn’t be the airplane. It would the carbon-based units being transported on said airplane. Medical emergencies take place every day. In fact, at least three times a week, I hear a crew calling either ATC or the company about a passenger having a problem.
Of those, my own unscientific analysis seems to indicate that losing consciousness or having what appears to be a heart attack or a stroke top the list. I don’t know this, of course, but I hear an awful lot of discussion about those symptoms (it’s pretty hard to misdiagnose someone as passed out when they are out cold). Some of these get interesting too. Seizures can be dangerous not just for the victim, but also for those around them. They can be messy as well (use your imagination). Ladies going into labor get everyone’s attention. Guess how I know that?
Some emergencies you can practice for, and some you can’t. Some you shouldn’t just because it isn’t very safe to do so. But in your own mind, you should have a definition that suits your equipment and your experience. Should you find yourself within the bounds of that definition, then declare an emergency. As for the rumored “mountains” of paperwork? There is no such thing. ATC may ask for your contact info, but nobody is going to fault you, and nobody is going to be having you filling out piles of forms in triplicate or even in double-icate. Honestly, it’s no big deal. As a matter of fact, if an emergency situation clears itself (say your landing gear had a gremlin, but then acted normally and went to the commanded position), you can “undeclare” your emergency. If you want to, you can fill out a NASA ASRS form, but you are not required to fill anything out, so long as the airplane is not damaged.
Just don’t do what one crew did, and declare an emergency because the FMS/GPS quit and they didn’t think about navigating from VOR to VOR. I won’t say which airline it was for, but yes, it did happen. Once.—Chip Wright