More on the "seen it happen" front...
Flew with a student doing VOR approaches a while back and at about 4 miles the CDI went hard right to the stop over about 3 seconds. Student turned right as it went fully left, student turned left as it came back to centre. Start to finish, about 20 seconds.
On the ground, OOPS says I,
'1 missed call'
Dumb student didn't check phones off in the preflight pax brief
