Date: 201703
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Night
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Cargo Compartment Fire/Overheat Warning
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: On the Arrival; the Flight Crew experienced an aft cargo fire indication. We complied with the QRH; [advised ATC] and determined the nearest suitable airport; evaluating altitude; distance; flying time; weather; and airport facilities. We diverted to the nearest suitable airport. We notified Dispatch through ATC and ACARS and communicated with the Flight Attendants and Passengers. After landing; we stopped the aircraft on the runway and set the parking brake. We communicated to the Flight Attendants and Passengers to 'remain seated and wait for further instructions.'We started the APU and shut down both engines. We established communications with Fire and Rescue; and informed them of an aft cargo fire indication and let them know that it was clear to approach the aircraft. Fire and rescue inspected the aircraft and found no fire or heat damage and later communicated that everything was 'all clear.' Next; we communicated with the Flight Attendants and Passengers that the Emergency Personnel had not found any damage to the aircraft and that we would be safely starting engines and taxiing to the gate. Upon arrival at the gate; asked the Passengers to remain seated while we figured out the next course of action. One fire truck met the aircraft at the gate to confirm no damage in the aft cargo bin. I called Dispatch and Maintenance. Operations had limited Operations Personnel on duty and were not able to stay with the aircraft and give us personalized attention. At this point the Operations Control was trying to figure out the next course of action. At first; Company Maintenance and Dispatch discussed having Contract Maintenance clear and sign-off the aircraft and for us to continue. I expressed that this was not a plan that worked for me; nor for our Passengers. This is where I asked to speak to the Chief Pilot on Call. Chief Pilot on Call agreed with my assessment. By this time; the First Officer was approaching duty time limitations and would not be legal to continue flying; however; he remained on board to assist with the Passenger's wellbeing and to answer any questions or concerns. The next plan was to find another First Officer and move the passengers to another aircraft to continue to ZZZ. I spoke to the Flight Attendants and asked how they were doing and if they were ok to continue to ZZZ. Everyone was reluctantly willing to continue at this point. As we waited; I evaluated my personal fitness for duty and chose not to continue flying; notifying the Chief Pilot on Call. While coordinating the next course of action; the aft cargo fire alarm sounded again inadvertently. We had all Passengers and Crew calmly and orderly evacuate the aircraft into the jetway with their belongings. The cargo bin was inspected by the Flight Crew and no smoke or fire was observed. After tracking down an Agent; the Passengers were cleared from the jetway to the terminal to wait for further assistance. At this point the Flight Attendants chose not to continue flying duties with my full and complete support! The entire Crew was released from duty and provided a hotel room near the airport. Note: this aircraft was MELed by a prior Crew for the Cargo Fire Suppression System (MEL 26-19-XX). This MEL was reviewed and complied with prior to flight. This was the second leg of the day on this aircraft for the Flight Crew. Also; we had four commuting Flight Attendants on board that were flying to ZZZ to be in position for work the next day. They also found themselves in the middle of a stressful situation. There are several lessons learned and things I would have done different after looking back at the event. 1. In communicating with the Flight Attendants; I would have used the phrase 'prepare the cabin for arrival'. I did communicate the appropriate information for our situation; however; 'prepare the cabin for arrival' is a standard phrase that conveys what is expected. 2. In hindsight; after arriving at the gate; I would havehad the Passengers exit the aircraft to the terminal while we determined the next course of action. I would have done this before making a call to Dispatch and Maintenance. Unfortunately; I found myself on the phone longer than anticipated and in a situation where the Agent was busy with other flights. In spite of this; the First Officer and Flight Attendants did a very nice job of keeping the Passengers calm; informed; and taken care of. 3. We needed to have an Agent or another Company representative stay with the aircraft at the gate the entire time on the ground. I understand some stations are small and have limited staffing; however; in events like these it makes it very difficult to receive the support needed for the Crew and Passengers. 4. If I had to do it over again; I would have gotten the Chief Pilot on Call involved in the conversation from the start when I first called Dispatch and spoke to Maintenance. This possibly could have prevented spending time looking at options that did not make sense under the circumstances.




Synopsis: B737 Captain reported a diversion due to an aft cargo fire indication. The cargo bin was inspected and no smoke nor fire was observed.