Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 200; Flight Crew Type 6397
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem
Aircraft
During cruise flight; at FL360; #1 engine drive light illuminated. Completed QRH; disconnected drive and attempted APU start. APU started. Placed on buss. APU performed auto shutdown. Began diversion to [a nearby alternate]. Descended to FL220; and attempted APU restart. APU restarted and stayed running. Oil temp; pressure and quantity remained stable. Monitored engine and canceled diversion. Discussed possible diversion airports if situation changed. Situation remained stable and unchanged. Requested priority handling to [destination]. Situation remained unchanged and continued on. Landing normal.
B737NG Captain reported the APU initially failed to pick up the electrical load following a malfunction of the #1 engine generator drive; but operated normally after descending to a lower altitude.