Narrative:

We were at 15;000 ft in cruise when my first officer and I noticed the smoke warning annunciator come on. We were approximately 30 miles to the south of a suitable divert airport and advised ATC we needed to divert there. We ran our checklist; advised the flight attendant and diverted immediately. I had the flight attendant cautiously check the back of the plane for signs of smoke and fire to which she found no evidence of the kind. I made a PA to the passengers advising them we were diverting and to wait for further instructions from our flight attendant. Within 10 minutes we were on the ground and met by emergency equipment and personnel. They inspected the cargo area and found no evidence of smoke or fire. After about 15 minutes of inspecting the aircraft we continued our taxi to the gate where we de-planed and proceeded with the associated MEL. From what I can tell from the aircraft maintenance log this is the second time this has happened in 10 days. It's discouraging to know this is an ongoing issue. The smoke warning annunciator was flickering on and off in the beginning but as we were landing it was continuously illuminating on and off until we were about 2 miles out. From 2 miles out it never came on again even after we were on the ground. I must say my crew did an excellent job in handling the diversion; it went smoothly and efficiently. I'm thankful for the knowledge and professionalism of both first officer and flight attendant

Google
 

Original NASA ASRS Text

Title: A DHC8-300 Captain described an apparent false cargo smoke warning which caused him to declare an emergency and divert to a nearby airport. This was a repeat of a previous false alert.

Narrative: We were at 15;000 ft in cruise when my First Officer and I noticed the smoke warning annunciator come on. We were approximately 30 miles to the south of a suitable divert airport and advised ATC we needed to divert there. We ran our checklist; advised the Flight Attendant and diverted immediately. I had the Flight Attendant cautiously check the back of the plane for signs of smoke and fire to which she found no evidence of the kind. I made a PA to the passengers advising them we were diverting and to wait for further instructions from our Flight Attendant. Within 10 minutes we were on the ground and met by emergency equipment and personnel. They inspected the cargo area and found no evidence of smoke or fire. After about 15 minutes of inspecting the aircraft we continued our taxi to the gate where we de-planed and proceeded with the associated MEL. From what I can tell from the aircraft maintenance log this is the second time this has happened in 10 days. It's discouraging to know this is an ongoing issue. The smoke warning annunciator was flickering on and off in the beginning but as we were landing it was continuously illuminating on and off until we were about 2 miles out. From 2 miles out it never came on again even after we were on the ground. I must say my crew did an excellent job in handling the diversion; it went smoothly and efficiently. I'm thankful for the knowledge and professionalism of both First Officer and Flight Attendant

Data retrieved from NASA's ASRS site as of April 2012 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.