Narrative:

Shortly after takeoff from international airport I was notified from the flight attendant that the cover on the right engine was loose. The first officer looked and noticed a bulge in the outer cowling of the right engine indicating that it was loose. We immediately called ATC and requested a return to the airport. We discussed our landing weight which was under our maximum landing weight and kept our speed under 160 KTS to prevent any further problems. We landed safely and returned to the gate without any further incidence. The maintenance workers met us at the gate and told me that he forgot to secure the cowling after his last safety inspection. There are 3 main contributing factors to this event. One is the failure of the maintenance worker to secure the cowling after his inspection. Two, is the failure of the first officer to complete a proper walkaround after leaving and subsequently returning to the aircraft. Third, is the failure on my part to ensure a proper preflight walkaround was completed.

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Original NASA ASRS Text

Title: AN S340B ON CLB AT 4000 FT DIVERTED DUE TO R ENG COWLING LATCHES NOT SECURED. LATCHES WERE NOT SECURED AFTER MAINT INSPECTION.

Narrative: SHORTLY AFTER TKOF FROM INTL ARPT I WAS NOTIFIED FROM THE FLT ATTENDANT THAT THE COVER ON THE R ENG WAS LOOSE. THE FO LOOKED AND NOTICED A BULGE IN THE OUTER COWLING OF THE R ENG INDICATING THAT IT WAS LOOSE. WE IMMEDIATELY CALLED ATC AND REQUESTED A RETURN TO THE ARPT. WE DISCUSSED OUR LNDG WT WHICH WAS UNDER OUR MAX LNDG WT AND KEPT OUR SPD UNDER 160 KTS TO PREVENT ANY FURTHER PROBS. WE LANDED SAFELY AND RETURNED TO THE GATE WITHOUT ANY FURTHER INCIDENCE. THE MAINT WORKERS MET US AT THE GATE AND TOLD ME THAT HE FORGOT TO SECURE THE COWLING AFTER HIS LAST SAFETY INSPECTION. THERE ARE 3 MAIN CONTRIBUTING FACTORS TO THIS EVENT. ONE IS THE FAILURE OF THE MAINT WORKER TO SECURE THE COWLING AFTER HIS INSPECTION. TWO, IS THE FAILURE OF THE FO TO COMPLETE A PROPER WALKAROUND AFTER LEAVING AND SUBSEQUENTLY RETURNING TO THE ACFT. THIRD, IS THE FAILURE ON MY PART TO ENSURE A PROPER PREFLT WALKAROUND WAS COMPLETED.

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.