Narrative:

During postflt for flight, and preflight for next flight, found area of delamination of composite portion of right engine cowl. This delamination was approximately 6 ft high and over 4 ft wide. Almost the entire outboard skin of the outboard rear cowl was missing. No other damage found. Nothing during this flight was in the slightest abnormal. The worst turbulence en route was light to moderate. No rain or precipitation of any kind. There were no speed anomalies out of the ordinary. Spoilers were used during descent with power due to an over-fueling event and landing weight limit concerns but nothing abnormal with this. I have no explanation but material failure.

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Original NASA ASRS Text

Title: DURING ENRTE EXTERIOR INSPECTION FLT CREW OF B757 DISCOVER A LARGE PORTION OF THE R ENG COWLING TO HAVE SEPARATED FROM THE AIRFRAME AT SOME POINT DURING PREVIOUS FLT SEGMENT.

Narrative: DURING POSTFLT FOR FLT, AND PREFLT FOR NEXT FLT, FOUND AREA OF DELAMINATION OF COMPOSITE PORTION OF R ENG COWL. THIS DELAMINATION WAS APPROX 6 FT HIGH AND OVER 4 FT WIDE. ALMOST THE ENTIRE OUTBOARD SKIN OF THE OUTBOARD REAR COWL WAS MISSING. NO OTHER DAMAGE FOUND. NOTHING DURING THIS FLT WAS IN THE SLIGHTEST ABNORMAL. THE WORST TURB ENRTE WAS LIGHT TO MODERATE. NO RAIN OR PRECIPITATION OF ANY KIND. THERE WERE NO SPD ANOMALIES OUT OF THE ORDINARY. SPOILERS WERE USED DURING DSCNT WITH PWR DUE TO AN OVER-FUELING EVENT AND LNDG WT LIMIT CONCERNS BUT NOTHING ABNORMAL WITH THIS. I HAVE NO EXPLANATION BUT MATERIAL FAILURE.

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.