MD-11
Flight Crew Air Transport Pilot (ATP)
Confusion
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed in Emergency Condition; General Maintenance Action
Aircraft
In cruise at FL390; received a Level 1 AIR SYS 3 OFF alert. Air synoptic showed WING A-ICE DISAG and associated consequences for the alert. Air system 3 was red from the engine pneumatic supply all the way to the pack and wing anti-ice valve. Noticed Bleed #3 was OFF and red MANF light illuminated on the overhead panel. Consulted QRH for all indications; but we had not received a manifold failure alert or an aural warning. We were just abeam ZZZ; so the Captain called maintenance there via VHF. Meanwhile; we looked at the QRH emergency procedure for manifold failure as well. When maintenance said that the overhead light was enough to indicate a manifold failure; we immediately [advised ATC] and began an emergency descent into ZZZ in accordance with QRH guidance. About halfway through the descent; the AIR MANF 3 FAIL Level 3 alert came on with associated aural warning. This went out sometime below 10;000 feet. We stopped on the runway while fire crews assessed the aircraft with temperature sensors. After receiving the all clear from them; we taxied uneventfully to the gate with an escort from the fire trucks.
MD11 First Officer received a Level 1 AIR SYS 3 OFF alert indicating a duct failure while at FL390; but no manifold failure alert or an aural warning. After consulting with Maintenance; the crew elected to divert to the nearest suitable airport.