Narrative:

Proposed departure was from jeffco airport for a part 91 company flight. We arrived at jeffco at XA45 and I removed sensor covers while the captain removed engine covers and preflted aft compartment. I did an exterior preflight per falcon jet's preflight procedures. Center engine cowl latches were latched. All checks complete, and a takeoff, clearance issued, we departed runway 29R at jeffco. Initial climb was normal. Going through about 13000 ft the turbulence increase, we picked up a buffet and climb rate decreased. (We attributed this to possible mountain wave effect.) proper anti-ice measures were used in the climb, and we were step-climbed to FL270 where we requested a time to level and accelerate. At FL270 we were not able to accelerate beyond 270 KTS and realized we had something wrong. We checked slats and flaps, airbrakes, and landing gear indicators -- all were normal. We were approximately 140 NM from lincoln and diverted to lnk to check the aircraft out. Approach and landing were normal. On arrival at FBO ramp and deplaning we discovered we had lost the left center engine cowling and the right center engine cowling was deformed and not in its normal position. Callback conversation with reporter revealed the following information: the reporter said the preflight check was done per the manufacturer's manual and the latches appeared locked and flush with the cowling surface. The reporter stated this center engine cowling has been troublesome when opening and closing and it can be false latched with no visual indication of latch condition. The reporter said the only change to our preflight check has been to make the check and avoid any interruption in the process. The reporter said the left cowling damaged the right cowling and put 2 creases in the left elevator which required replacement.

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Original NASA ASRS Text

Title: A FALCON 50 IN CRUISE AT FL270 HAD THE L CTR ENG COWLING DEPART THE ACFT INCURRING DAMAGE TO THE R CTR ENG COWLING AND DAMAGING THE L ELEVATOR.

Narrative: PROPOSED DEP WAS FROM JEFFCO ARPT FOR A PART 91 COMPANY FLT. WE ARRIVED AT JEFFCO AT XA45 AND I REMOVED SENSOR COVERS WHILE THE CAPT REMOVED ENG COVERS AND PREFLTED AFT COMPARTMENT. I DID AN EXTERIOR PREFLT PER FALCON JET'S PREFLT PROCS. CTR ENG COWL LATCHES WERE LATCHED. ALL CHKS COMPLETE, AND A TKOF, CLRNC ISSUED, WE DEPARTED RWY 29R AT JEFFCO. INITIAL CLB WAS NORMAL. GOING THROUGH ABOUT 13000 FT THE TURB INCREASE, WE PICKED UP A BUFFET AND CLB RATE DECREASED. (WE ATTRIBUTED THIS TO POSSIBLE MOUNTAIN WAVE EFFECT.) PROPER ANTI-ICE MEASURES WERE USED IN THE CLB, AND WE WERE STEP-CLBED TO FL270 WHERE WE REQUESTED A TIME TO LEVEL AND ACCELERATE. AT FL270 WE WERE NOT ABLE TO ACCELERATE BEYOND 270 KTS AND REALIZED WE HAD SOMETHING WRONG. WE CHKED SLATS AND FLAPS, AIRBRAKES, AND LNDG GEAR INDICATORS -- ALL WERE NORMAL. WE WERE APPROX 140 NM FROM LINCOLN AND DIVERTED TO LNK TO CHK THE ACFT OUT. APCH AND LNDG WERE NORMAL. ON ARR AT FBO RAMP AND DEPLANING WE DISCOVERED WE HAD LOST THE L CTR ENG COWLING AND THE R CTR ENG COWLING WAS DEFORMED AND NOT IN ITS NORMAL POS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THE PREFLT CHK WAS DONE PER THE MANUFACTURER'S MANUAL AND THE LATCHES APPEARED LOCKED AND FLUSH WITH THE COWLING SURFACE. THE RPTR STATED THIS CTR ENG COWLING HAS BEEN TROUBLESOME WHEN OPENING AND CLOSING AND IT CAN BE FALSE LATCHED WITH NO VISUAL INDICATION OF LATCH CONDITION. THE RPTR SAID THE ONLY CHANGE TO OUR PREFLT CHK HAS BEEN TO MAKE THE CHK AND AVOID ANY INTERRUPTION IN THE PROCESS. THE RPTR SAID THE L COWLING DAMAGED THE R COWLING AND PUT 2 CREASES IN THE L ELEVATOR WHICH REQUIRED REPLACEMENT.

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.