MD-82
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution
Aircraft
After push back from our gate at ZZZ; we started the left engine. The left generator failed to come on line; so we were towed back to the gate and advised maintenance of our problem. Maintenance placarded the left engine generator per MEL and we were dispatched with the APU generator and the right engine-driven generator. After approximately one hour of flight; at FL290; the APU flamed out leaving us with only one generator. [ATC was advised] and we diverted to [a suitable airport]. The cabin crew was briefed and a PA was made to the passengers. The QRH was performed; and an attempt to start the APU was made. We were unable to restart it. After an uneventful landing [we] taxied to the gate.
As soon as the APU shut down; we both knew where we were diverting to; and what steps needed to be accomplished to configure the aircraft. The only workload left to be done was fly the aircraft; coordinate with the cabin crew; and coordinate with ATC.
MD-82 flight crew reported diverting to a suitable alternate when the APU failed after being dispatched with the left generator inoperative.