[jlgreco]

Probably not a problem when there is a human flying it, but I wonder how difficult it would be to get an autopilot to recognise/deal with gimbal lock.

[mistercow]

Recognizing gimbal lock wouldn't be very difficult. Using a rotary encoder on each axis, you could measure their angles and tell if any pair of gimbals was aligned. And apparently there are techniques for arbitrarily rotating one gimbal when lock is detected.

[jlgreco]

That would require making the gimbals higher tech than they currently are now though.

I'm wondering if you could perhaps detect it by detecting a sudden unplanned twist around one axis with an onboard accelerometer.

[mistercow]

It doesn't really add that much complexity to the gimbals. Rotary encoders are extremely inexpensive, and the information would just be interpreted by the central controller.