737 NG A/P hickup...
Intercepting an ILS, at LOC/GS capture I was surprised to see the autopilot struggling to follow F/D commands. We were clearly not following the cross and we were going up and down like a yo-yo and also banking back and forth. The signal on our screens seemed stable, so I just wonder what can have caused this? The plane was an old one in RYR terms.
Another situation I've had is LOC/GS interception with an unreliable GS, the A/P kept pithching up and down in a rather dramatic way, so we disconnected...at what point would it disconnect by itself? It was quite nasty.