What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Crew had 2 separate aft cargo fire indications. Both indications went away on their own. They briefed the qrh checklist in anticipation and pulled weather for kboi. A 3rd fire indication was received and remained illuminated. The crew declared a mayday and ask for a diversion to kboi.
ARFF attended the aircraft and advised there was no sign of fire and gave the okay at 1708Z. ARFF trucks followed the aircraft to the gate and once parked, inspected the cargo hold. There was no indication of fire onboard the aircraft.
After troubleshooting the issue, maintenance found that the aft cargo electronic control unit p/n 473925 was faulty. A new unit was installed, and the aircraft returned to service
As the FAA filed it
CREW HAD 2 SEPARATE AFT CARGO FIRE INDICATIONS. BOTH INDICATIONS WENT AWAY ON THEIR OWN. THEY BRIEFED THE QRH CHECKLIST IN ANTICIPATION AND PULLED WEATHER FOR KBOI. A 3RD FIRE INDICATION WAS RECEIVED AND REMAINED ILLUMINATED. THE CREW DECLARED A MAYDAY AND ASK FOR A DIVERSION TO KBOI.
ARFF ATTENDED THE AIRCRAFT AND ADVISED THERE WAS NO SIGN OF FIRE AND GAVE THE OKAY AT 1708Z. ARFF TRUCKS FOLLOWED THE AIRCRAFT TO THE GATE AND ONCE PARKED, INSPECTED THE CARGO HOLD. THERE WAS NO INDICATION OF FIRE ONBOARD THE AIRCRAFT.
AFTER TROUBLESHOOTING THE ISSUE, MAINTENANCE FOUND THAT THE AFT CARGO ELECTRONIC CONTROL UNIT P/N 473925 WAS FAULTY. A NEW UNIT WAS INSTALLED, AND THE AIRCRAFT RETURNED TO SERVICE