Not unusual or very surprising. Here’s why: The “Black Box” is permanently installed in the aircraft (it can be removed, but only for service). You want it to go everywhere the jet goes, recording all the time. It’s designed to record until power is cut – presumably in a crash.

Not unusual or very surprising. Here’s why: The “Black Box” is permanently installed in the aircraft (it can be removed, but only for service). You want it to go everywhere the jet goes, recording all the time. It’s designed to record until power is cut – presumably in a crash. But, it can’t record every minute of the jet’s entire life…memory space is limited & we don't want to have to change out tapes or something after every flight (they are digital). So, it recycles the available memory, which is about 2 hours. At any given moment, the box has the last two hours of the flight on record. Exactly what it records varies by model; some only record voice, while others can record almost every aspect of the airplane’s movement & systems status (like if the flaps are out, the airspeed, what the pilot is doing to the yoke, etc.). In a crash, the power gets cut, it stops recording & just stores that data. When you manage to land safely, though, the recorder just keeps going unless you manually cut off the power. Because we want the recorder to always normally be on, it's not routine to cut off the power…it's not part of our normal or emergency checklists to do so. (checking that its operating normally is part of the preflight procedure, though) At the end of an emergency, after successfully landing & getting the engines shut down, there's no checklist that tells you to do it (the military kind of had one, but I haven't seen one at the airline). So…after keeping calm, doing your job, executing procedures that you only ever see in the simulator, you finish that last checklist. You can let go…all the stress, emotion & everything else you've been pushing back can come forward…you kind of just slump in the chair, exhale & maybe your body finally relaxes. That time you were told to pull the circuit breaker after a serious emergency, 10 years ago? It doesn't make it to the top of your mind. Responding emergency crews aren't trained to do it. Gate agents & ramp personnel aren't, either. Some maintenance folks have an idea to do it, but they may not get on the plane for quite a while…there are higher priorities after a mishap, like getting the passengers off the jet. It gets missed and just goes on recording, erasing everything but the last two hours.