Q: iPad crashes and wont reboot after upgrade to iOS 8.1.3

I just upgraded to iOS 8.3.1, and since then my iPad Air (1) has crashed twice. Each time, it has been very problematic to reboot.

The first time it crashed I was zooming a photo on a web page in Safari. The second time I was using an iPhone app, and switched the magnification to 1x. Each time the screen flickered blue and then switched off. The sleep/wake button had no effect.

I tried to reboot by holding the sleep/wake and home buttons for ten seconds. Doing this caused one of three situations:

1. The system loops in a continuous reboot cycle as follows: the white apple appears, fades to grey, then there is a blue flicker, the screen switches off and the reboot cycle starts again.
2. The screen displays a constant dim grey. Sleep/wake has no effect (even when pressed and held).
3. The screen stays off. Pressing and holding sleep/wake for a few seconds caused the reboot cycle to start again (number 1).

I tried many times to reboot, by pressing and holding the sleep/wake and home buttons for 10 seconds at various stages in the reboot cycle. Eventually the reboot was successful, but I am not sure what "magic" caused it to work after failing (more than ten tries to reboot each time).

The only thing I can think of (and I know it sounds silly) is that both times it rebooted, I left it flat with the white apple displayed for several minutes. When I came back to it the reboot was successful. Next time it crashes (as I am sure it will) I will try this technique first, and report back here if it is successful.