Narrative:

On a preflight inspection the left oil temperature gauge was inoperative. I advised maintenance and wrote up the discrepancy. The maintenance people repaired the discrepancy on the left engine. After their departure, I did my normal aircraft walk-around and visually checked that all cowling latches were secure. I also pounded on the cowling to check the physical security as I always do. They remained intact. The passenger were boarded. My first officer also performed his walk-around to check the door latches, cowling latches and fueling door. Start-up and taxi-out were under normal operating procedures. ATC cleared us for takeoff on runway 4R. At 500' AGL during the turn I noticed a slight vibration on the control panel. I checked the engine INS and all appeared normal. At level-off at 3000' MSL I noticed the airspeed was lower than normal for the conditions. I looked out the left window and noticed that the left engine upper cowling was missing. I instructed my first officer to advise ATC that we needed to return to mdw. ATC advised us that it would be approximately 30 mins. At that point I decided with IMC conditions, 19 passenger on board and possible damage to the tail surface to declare an emergency to get priority handling. The approach and descent checklist was performed. I decided with possible damage to the tail surface to do a flaps 1 landing with a vref + 15 KTS. Operations was advised of our situation. I flew the 4R ILS into mdw and landed west/O incident. We taxied unassisted to the gate. Upon exiting the aircraft we found the cowling was still attached to the aircraft on a hinge pin. Minor damage was sustained to the loose cowling.

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Original NASA ASRS Text

Title: COMMUTER SMT'S ENGINE COWL CAME OPEN DURING CLIMBOUT FROM MDW. PIC DECLARED AN EMERGENCY AND RETURNED TO MDW.

Narrative: ON A PREFLT INSPECTION THE LEFT OIL TEMP GAUGE WAS INOP. I ADVISED MAINT AND WROTE UP THE DISCREPANCY. THE MAINT PEOPLE REPAIRED THE DISCREPANCY ON THE LEFT ENG. AFTER THEIR DEP, I DID MY NORMAL ACFT WALK-AROUND AND VISUALLY CHKED THAT ALL COWLING LATCHES WERE SECURE. I ALSO POUNDED ON THE COWLING TO CHK THE PHYSICAL SECURITY AS I ALWAYS DO. THEY REMAINED INTACT. THE PAX WERE BOARDED. MY F/O ALSO PERFORMED HIS WALK-AROUND TO CHK THE DOOR LATCHES, COWLING LATCHES AND FUELING DOOR. START-UP AND TAXI-OUT WERE UNDER NORMAL OPERATING PROCS. ATC CLRED US FOR TKOF ON RWY 4R. AT 500' AGL DURING THE TURN I NOTICED A SLIGHT VIBRATION ON THE CTL PANEL. I CHKED THE ENG INS AND ALL APPEARED NORMAL. AT LEVEL-OFF AT 3000' MSL I NOTICED THE AIRSPD WAS LOWER THAN NORMAL FOR THE CONDITIONS. I LOOKED OUT THE LEFT WINDOW AND NOTICED THAT THE LEFT ENG UPPER COWLING WAS MISSING. I INSTRUCTED MY F/O TO ADVISE ATC THAT WE NEEDED TO RETURN TO MDW. ATC ADVISED US THAT IT WOULD BE APPROX 30 MINS. AT THAT POINT I DECIDED WITH IMC CONDITIONS, 19 PAX ON BOARD AND POSSIBLE DAMAGE TO THE TAIL SURFACE TO DECLARE AN EMER TO GET PRIORITY HANDLING. THE APCH AND DSNT CHKLIST WAS PERFORMED. I DECIDED WITH POSSIBLE DAMAGE TO THE TAIL SURFACE TO DO A FLAPS 1 LNDG WITH A VREF + 15 KTS. OPS WAS ADVISED OF OUR SITUATION. I FLEW THE 4R ILS INTO MDW AND LANDED W/O INCIDENT. WE TAXIED UNASSISTED TO THE GATE. UPON EXITING THE ACFT WE FOUND THE COWLING WAS STILL ATTACHED TO THE ACFT ON A HINGE PIN. MINOR DAMAGE WAS SUSTAINED TO THE LOOSE COWLING.

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.