Narrative:

On preflight walkaround noted all cowlings closed and locked, verified visually and with pull on each cowling half. Upon arrival, we noted #1 engine cowlings missing from aircraft. Entire flight was normal, all engine parameters normal. We had no idea cowlings had fallen off. I suspect this could be an aging aircraft issue, or possibly related to stc sa 5455NM (stage III noise reduction) which includes modifications to cowlings and duct work. Cowling was found at phl still latched with failure noted at attachment pins (preliminary company finding). Suggest possible one time fleet directive or airworthiness directive. Maybe company should make latching cowlings a required inspection item procedure. Callback conversation with reporter revealed the following information: the reporter stated the aircraft was a DC8-63 with P&west JTD3-7 engines. The reporter said the cowling was checked on the preflight walkaround inspection and all engines were ok. The reporter stated the aircraft was recently modified to meet stage 3 noise requirements and some cowling work was accomplished. The reporter said this work was done sometime prior to this flight. The reporter said the maintenance preliminary report was either false latching of the upper pylon to cowling hinge pins or outright failure of the pins due to aging. The only damage to the airplane other than the cowling was #1 engine left side bifurcated duct damaged and minor scratches to the lower wing surface.

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Original NASA ASRS Text

Title: A DC8-63 ON TKOF AT ROTATION THE #1 ENG L AND R SIDE COWLING DEPARTED THE ACFT.

Narrative: ON PREFLT WALKAROUND NOTED ALL COWLINGS CLOSED AND LOCKED, VERIFIED VISUALLY AND WITH PULL ON EACH COWLING HALF. UPON ARR, WE NOTED #1 ENG COWLINGS MISSING FROM ACFT. ENTIRE FLT WAS NORMAL, ALL ENG PARAMETERS NORMAL. WE HAD NO IDEA COWLINGS HAD FALLEN OFF. I SUSPECT THIS COULD BE AN AGING ACFT ISSUE, OR POSSIBLY RELATED TO STC SA 5455NM (STAGE III NOISE REDUCTION) WHICH INCLUDES MODIFICATIONS TO COWLINGS AND DUCT WORK. COWLING WAS FOUND AT PHL STILL LATCHED WITH FAILURE NOTED AT ATTACHMENT PINS (PRELIMINARY COMPANY FINDING). SUGGEST POSSIBLE ONE TIME FLEET DIRECTIVE OR AIRWORTHINESS DIRECTIVE. MAYBE COMPANY SHOULD MAKE LATCHING COWLINGS A REQUIRED INSPECTION ITEM PROC. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ACFT WAS A DC8-63 WITH P&W JTD3-7 ENGS. THE RPTR SAID THE COWLING WAS CHKED ON THE PREFLT WALKAROUND INSPECTION AND ALL ENGS WERE OK. THE RPTR STATED THE ACFT WAS RECENTLY MODIFIED TO MEET STAGE 3 NOISE REQUIREMENTS AND SOME COWLING WORK WAS ACCOMPLISHED. THE RPTR SAID THIS WORK WAS DONE SOMETIME PRIOR TO THIS FLT. THE RPTR SAID THE MAINT PRELIMINARY RPT WAS EITHER FALSE LATCHING OF THE UPPER PYLON TO COWLING HINGE PINS OR OUTRIGHT FAILURE OF THE PINS DUE TO AGING. THE ONLY DAMAGE TO THE AIRPLANE OTHER THAN THE COWLING WAS #1 ENG L SIDE BIFURCATED DUCT DAMAGED AND MINOR SCRATCHES TO THE LOWER WING SURFACE.

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.