Cells and navx
I've experienced only once a problem on a MD83 during approach. We were close to 10000 when we've start hearing the clicking noise of a cell phone on the radio and at the same time FO's horizon was going nuts and went 45 degres bank 10 degres up totally frozen. Captain's side was normal. After 20 seconds we've made a PAX announcement and told that our instrumentation was disturbed by a cell phone and that all cells should remain off. The clicking noise of the cell phone in the radio stopped a couple of seconds later and FO's instrument resumed normal operation.