DC-10 30
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue; Inflight Event / Encounter Weather / Turbulence
General Declared Emergency
Aircraft; Weather
Descending through FL190 all three of the Captain's DUs [Display Units] went blank. I immediately transferred the airplane to the First Officer whose DUs were fine. I then did the in range checklist and made sure our altimeters were set correctly. The First Officer subsequently lost his FMC. The Captain's side came back but only in the standby mode. We able to get first officer's side [FMC] back but it subsequently failed again. We decided to declare an emergency to get radar vectors to final and receive priority handling since there was mountainous terrain and fuel was starting to be a factor although either at the time was VMC. We determined the landing speeds from the QRH for our weight; [and] then flew a visual approach to a landing runway. The First Officer flew the visual approach since his side had better data when compared to the standby airspeed. We figure we had a dual FMC failure; probably caused by rain at our departure airport.
...deviating around weather using our on board radar north of the arrival course...FMC data returned after landing. Prior to our departure; heavy thunderstorms were experienced at the ramp. The aircraft's electronics bay may possibly have been contaminated with rain water. After arrival at the ramp; mechanics reported to us that a lot of water was dripping from the underside of the aircraft.
A DC-10 flight crew suffered recurring failures of display units and FMCs during their descent to a safe landing in VMC. Heavy rains at the ramp prior to their departure may have entered the aircraft before takeoff as ramp personnel noted water dripping from the underside of the aircraft as they taxied in the ramp following the incident.