MD-80 Series (DC-9-80) Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Aircraft Equipment Problem Less Severe
Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Landed As Precaution; Flight Crew FLC Overrode Automation
Aircraft
We departed on the STAR off of Runway 25R.  Passing through approximately 9;000 ft; the autopilot disengaged; First Officer's (FO) flight director disappeared; and FO's Flight Mode Annunciator (FMA) ARM; ROLL; and PITCH mode windows went blank. The Captain's side was still working and we switched Flight Director (FD) selector operative system. We ran the QRH procedure for a blank FMA and after a few minutes the autopilot disengaged again and both flight directors and FMA blanked. We leveled off with ATC approval below RVSM airspace; and coordinated to return to the airport.  While descending; the flight directors started working again. We landed uneventfully.  This aircraft has multiple pieces of equipment in the cockpit that are different from the other aircraft in the fleet. Crews must maintain a vigilant crosscheck of these systems to ensure they are operating as expected. Differences in flight management techniques due to the lack of VNAV and different type of FMS controls should be thoroughly briefed prior to departure.
MD-80 First Officer reported during climb the autopilot disconnected; the First Officer's flight director disappeared; and the flight mode annunciator's ARM; ROLL; and PITCH mode windows went blank.