Narrative:

En route from fhu to phx, there were intermittent smells of electrical smoke. We could not determine if anything was on fire or smoking due to the occurrences being so intermittent (about 15 mins apart). When we were about 15 mi southeast of phx, we detected smoke and I deployed oxygen to the crew and cabin. We determined that the smoke was coming from the air eyeball outlets and turned the environment controls off. I also dumped cabin pressure and turned the vent air on. The smoke cleared and the first officer took off his oxygen mask. Until this point, communications were impossible due to the hot interphone switch being inoperative. The flow of oxygen over the microphone in the mask made enough noise to drown out ATC communications and crew communication. I believe we missed 2-3 calls until the smoke cleared and we determined that the use of oxygen was no longer needed. Approach control asked us if we were going to descend and if we had the airport in sight. We acknowledged and turned toward the airport. There were no traffic conflicts and the flight ended without further incident. No passenger complained of having difficulties. Maintenance personnel inspected the aircraft and determined that the front blower motor had burned out and was the cause of the smoke. The biggest concern we had was our loss of communication with ATC and each other. If the hot interphone system had been operating properly, we could have handled the problem much easier.

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Original NASA ASRS Text

Title: AN ACR LTT BURNED UP A BLOWER MOTOR. AS THE HOT INTERPHONE IN THE OXYGEN MASKS WAS INOP, COM BTWN THE PLTS AND BTWN TRACON WAS DIFFICULT.

Narrative: ENRTE FROM FHU TO PHX, THERE WERE INTERMITTENT SMELLS OF ELECTRICAL SMOKE. WE COULD NOT DETERMINE IF ANYTHING WAS ON FIRE OR SMOKING DUE TO THE OCCURRENCES BEING SO INTERMITTENT (ABOUT 15 MINS APART). WHEN WE WERE ABOUT 15 MI SE OF PHX, WE DETECTED SMOKE AND I DEPLOYED OXYGEN TO THE CREW AND CABIN. WE DETERMINED THAT THE SMOKE WAS COMING FROM THE AIR EYEBALL OUTLETS AND TURNED THE ENVIRONMENT CTLS OFF. I ALSO DUMPED CABIN PRESSURE AND TURNED THE VENT AIR ON. THE SMOKE CLRED AND THE FO TOOK OFF HIS OXYGEN MASK. UNTIL THIS POINT, COMS WERE IMPOSSIBLE DUE TO THE HOT INTERPHONE SWITCH BEING INOP. THE FLOW OF OXYGEN OVER THE MIKE IN THE MASK MADE ENOUGH NOISE TO DROWN OUT ATC COMS AND CREW COM. I BELIEVE WE MISSED 2-3 CALLS UNTIL THE SMOKE CLRED AND WE DETERMINED THAT THE USE OF OXYGEN WAS NO LONGER NEEDED. APCH CTL ASKED US IF WE WERE GOING TO DSND AND IF WE HAD THE ARPT IN SIGHT. WE ACKNOWLEDGED AND TURNED TOWARD THE ARPT. THERE WERE NO TFC CONFLICTS AND THE FLT ENDED WITHOUT FURTHER INCIDENT. NO PAX COMPLAINED OF HAVING DIFFICULTIES. MAINT PERSONNEL INSPECTED THE ACFT AND DETERMINED THAT THE FRONT BLOWER MOTOR HAD BURNED OUT AND WAS THE CAUSE OF THE SMOKE. THE BIGGEST CONCERN WE HAD WAS OUR LOSS OF COM WITH ATC AND EACH OTHER. IF THE HOT INTERPHONE SYS HAD BEEN OPERATING PROPERLY, WE COULD HAVE HANDLED THE PROB MUCH EASIER.

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.