Narrative:

Approximately midway through the flight we experienced a momentary loss of power in left engine; with a slight yaw. Then the left oil bypass light came on. Upon completion of the oil bypass light procedures; called dispatch to talk to maintenance control. During talking to maintenance control; my flight attendant called and notified me that a passenger who idented himself as a military pilot; had noticed a hole and skin coming off the left engine. Looking back from my seat; I noticed a hole where the AC exhaust hole is and the screen that normally goes over it was mostly gone. I also noticed that we had lost some skin behind the AC exhaust. We slowed the aircraft to maneuvering speed of 190 KTS. I discussed the option of declaring an emergency with dispatch. After receiving additional information from the flight attendant; I declared an emergency. I notified dispatch; flight attendant; and ATC that we were declaring an emergency. I notified the flight attendant to prepare the cabin. We went over seating arrangements; and if we needed to do an emergency exit; that I would call her. The rest of the flight went without any problems. Got direct; and a short approach. I shut down the left engine after clearing the runway; and proceeded to the ramp. The aircraft generator had been deferred by maintenance.

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Original NASA ASRS Text

Title: SF340 FLT CREW WITH DEFERRED AC GENERATOR HAS MOMENTARY LOSS OF NUMBER 1 ENGINE POWER INFLIGHT; SUBSEQUENT INSPECTION REVEALS BURN MARKS. EMERGENCY IS DECLARED AND UNEVENTFUL LANDING ENSUES.

Narrative: APPROX MIDWAY THROUGH THE FLT WE EXPERIENCED A MOMENTARY LOSS OF PWR IN L ENG; WITH A SLIGHT YAW. THEN THE L OIL BYPASS LIGHT CAME ON. UPON COMPLETION OF THE OIL BYPASS LIGHT PROCS; CALLED DISPATCH TO TALK TO MAINT CTL. DURING TALKING TO MAINT CTL; MY FLT ATTENDANT CALLED AND NOTIFIED ME THAT A PAX WHO IDENTED HIMSELF AS A MIL PLT; HAD NOTICED A HOLE AND SKIN COMING OFF THE L ENG. LOOKING BACK FROM MY SEAT; I NOTICED A HOLE WHERE THE AC EXHAUST HOLE IS AND THE SCREEN THAT NORMALLY GOES OVER IT WAS MOSTLY GONE. I ALSO NOTICED THAT WE HAD LOST SOME SKIN BEHIND THE AC EXHAUST. WE SLOWED THE ACFT TO MANEUVERING SPD OF 190 KTS. I DISCUSSED THE OPTION OF DECLARING AN EMER WITH DISPATCH. AFTER RECEIVING ADDITIONAL INFO FROM THE FLT ATTENDANT; I DECLARED AN EMER. I NOTIFIED DISPATCH; FLT ATTENDANT; AND ATC THAT WE WERE DECLARING AN EMER. I NOTIFIED THE FLT ATTENDANT TO PREPARE THE CABIN. WE WENT OVER SEATING ARRANGEMENTS; AND IF WE NEEDED TO DO AN EMER EXIT; THAT I WOULD CALL HER. THE REST OF THE FLT WENT WITHOUT ANY PROBS. GOT DIRECT; AND A SHORT APCH. I SHUT DOWN THE L ENG AFTER CLRING THE RWY; AND PROCEEDED TO THE RAMP. THE ACFT GENERATOR HAD BEEN DEFERRED BY MAINT.

Data retrieved from NASA's ASRS site as of May 2009 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.