Narrative:

We had a normal pushback and taxi out -- selected flaps 5 degrees for departure. Flight attendant then called cockpit to report a passenger claim that part of the 'wing' was missing. We stopped aircraft -- captain directed me to perform a visual inspection after following security procedure. I confirmed that a portion of the trailing edge inboard flap was missing and that the top half of the flap had delaminated and separated from the aircraft. We returned to the gate. Both the ground crew and myself had performed an exterior check of the aircraft. We did not notice the damage with the flaps retracted at the gate. Passenger noted seeing damage on pushback. The aircraft was removed from service for repair. The majority of the damage was on the top surface of the flap assembly. It was a clear sunny day and the missing piece of the flap was right by the fairing. It is possible that with a combination of the sun in our eyes and a shadowing effect from the fairing combined with the flaps being in the retracted position; the damage was missed on the exterior walkaround.

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Original NASA ASRS Text

Title: A B757-200 RETURNED TO THE GATE FOLLOWING A PAX DISCOVERY DURING TAXI FOR TKOF THAT A PORTION OF THE TRAILING EDGE FLAP WAS MISSING AND THAT THE TOP HALF OF THE FLAP HAD DELAMINATED.

Narrative: WE HAD A NORMAL PUSHBACK AND TAXI OUT -- SELECTED FLAPS 5 DEGS FOR DEP. FLT ATTENDANT THEN CALLED COCKPIT TO RPT A PAX CLAIM THAT PART OF THE 'WING' WAS MISSING. WE STOPPED ACFT -- CAPT DIRECTED ME TO PERFORM A VISUAL INSPECTION AFTER FOLLOWING SECURITY PROC. I CONFIRMED THAT A PORTION OF THE TRAILING EDGE INBOARD FLAP WAS MISSING AND THAT THE TOP HALF OF THE FLAP HAD DELAMINATED AND SEPARATED FROM THE ACFT. WE RETURNED TO THE GATE. BOTH THE GND CREW AND MYSELF HAD PERFORMED AN EXTERIOR CHK OF THE ACFT. WE DID NOT NOTICE THE DAMAGE WITH THE FLAPS RETRACTED AT THE GATE. PAX NOTED SEEING DAMAGE ON PUSHBACK. THE ACFT WAS REMOVED FROM SVC FOR REPAIR. THE MAJORITY OF THE DAMAGE WAS ON THE TOP SURFACE OF THE FLAP ASSEMBLY. IT WAS A CLEAR SUNNY DAY AND THE MISSING PIECE OF THE FLAP WAS RIGHT BY THE FAIRING. IT IS POSSIBLE THAT WITH A COMBINATION OF THE SUN IN OUR EYES AND A SHADOWING EFFECT FROM THE FAIRING COMBINED WITH THE FLAPS BEING IN THE RETRACTED POSITION; THE DAMAGE WAS MISSED ON THE EXTERIOR WALKAROUND.

Data retrieved from NASA's ASRS site as of January 2009 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.