Narrative:

During push back from gate x-y ZZZ. We had a smoke cargo indication. The captain shut down the #1 engine and we completed the smoke cargo checklist short of discharging the bottles. Captain was still in contact with ground personnel and had them open and confirm no fire or smoke in the cargo compartment. The number two engine was shut down and the aircraft was towed back to the gate. Passengers were deplaned thru normal exit and maintenance was called. We elected not to discharge the bottles or evacuate the passengers. It was a faulty message. This has occurred numerous times throughout our fleet and needs to be corrected by the maker. Callback conversation with reporter revealed the following information: the reporter stated the problem was a false warning caused by a faulty sensor. The reporter claims the master caution and 'smoke cargo' message are a recurring problem caused by faulty sensors. The reporter stated the airplane was still connected to the tug and after maintenance inspection and no smoke discovered they were towed to the gate and deplaned the passengers. Callback from acn 492256: the reporter stated the problem was caused by a faulty or dirty smoke sensor. The reporter claims maintenance made a study of the sensors and found the sensors mainly failed between 3000 hours and 4000 hours with the life cycle of the sensors being 5000 hours.

Related reports:

Google
 

Original NASA ASRS Text

Title: A CANADAIR CL65 DURING PUSHBACK HAD MASTER CAUTION AND 'SMOKE CARGO' MSG. VISUAL CHK BY PUSHBACK CREW REVEALED A FALSE WARNING.

Narrative: DURING PUSH BACK FROM GATE X-Y ZZZ. WE HAD A SMOKE CARGO INDICATION. THE CAPT SHUT DOWN THE #1 ENG AND WE COMPLETED THE SMOKE CARGO CHKLIST SHORT OF DISCHARGING THE BOTTLES. CAPT WAS STILL IN CONTACT WITH GND PERSONNEL AND HAD THEM OPEN AND CONFIRM NO FIRE OR SMOKE IN THE CARGO COMPARTMENT. THE NUMBER TWO ENG WAS SHUT DOWN AND THE ACFT WAS TOWED BACK TO THE GATE. PAXS WERE DEPLANED THRU NORMAL EXIT AND MAINT WAS CALLED. WE ELECTED NOT TO DISCHARGE THE BOTTLES OR EVACUATE THE PAXS. IT WAS A FAULTY MSG. THIS HAS OCCURRED NUMEROUS TIMES THROUGHOUT OUR FLEET AND NEEDS TO BE CORRECTED BY THE MAKER. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PROB WAS A FALSE WARNING CAUSED BY A FAULTY SENSOR. THE RPTR CLAIMS THE MASTER CAUTION AND 'SMOKE CARGO' MSG ARE A RECURRING PROB CAUSED BY FAULTY SENSORS. THE RPTR STATED THE AIRPLANE WAS STILL CONNECTED TO THE TUG AND AFTER MAINT INSPECTION AND NO SMOKE DISCOVERED THEY WERE TOWED TO THE GATE AND DEPLANED THE PAXS. CALLBACK FROM ACN 492256: THE RPTR STATED THE PROB WAS CAUSED BY A FAULTY OR DIRTY SMOKE SENSOR. THE RPTR CLAIMS MAINT MADE A STUDY OF THE SENSORS AND FOUND THE SENSORS MAINLY FAILED BTWN 3000 HRS AND 4000 HRS WITH THE LIFE CYCLE OF THE SENSORS BEING 5000 HRS.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.