B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 367; Flight Crew Type 8500
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; Flight Crew Landed in Emergency Condition
Aircraft
Climbing through approximately FL250 we got an AFT Cargo Fire indication. I called for the QRH and we ran the checklist. We followed the guidance of the QRH and pressed the aft discharge switch. We took note of the time and informed both ATC and Dispatch of the situation. Dispatch told us that [a nearby alternate] would be the closest airport and we relayed this to ATC. We leveled around FL300 and began a descent and turn towards [the alternate]. We informed both the Flight Attendants and passengers that we would divert. We informed Operations of the situation and asked them to relay to Aircraft Rescue and Firefighting to assess the situation without opening any cargo bin until all passengers deplaned the aircraft. Once we were on Tower frequency we established communication with Aircraft Rescue and Firefighting and again asked them to assess the cargo area. We stopped on the runway to give them time to evaluate the situation. Once we were reasonably sure there was no fire; we asked to taxi to the gate. Once at the gate we deplaned all passengers before opening any cargo bin.
B737 Captain reported diverting to an alternate airport after receiving an aft cargo fire warning. After landing it was determined there was no fire.