Last week on approach to EDI very short final, the aircraft moved left 30 degrees + off the localiser and dropped below glidepath purposely and smoothly. Captain and I after disbelief seconds recovered the situation PDQ but had we been in IMC and not good VM as we were, a certain go around. Hostie then advises us afterwards that a mobile had started ringing after the wheels were down but not exactly sure where on the approach.
Neither of us were sure if we had heard the usual buzzing in our headphones, but taking no chances have given full report to safety who have subsequently reinforced throughout the company the "switch the mobile off" speech and stamping it out from the FD if we hear anything in future.
The scarey thing was the way it looked as though one of us had just decided to turn off the path. I suppose thinking about mobile interference I might have expected the systems to disengage or jolt somewhat with the usual cavalry charge lights flashing warnings but it didn't. It just seemed to set a new course........one to watch