Narrative:

During cruise flight a slight right wing heavy indication was noted and was easily corrected by the autoplt. Next indication appeared during descent by a noise/vibration that was corrected by a slight speed reduction and pitch change. Obvious problem did not occur until final when gear was lowered and a very loud and obvious vibration was felt. Once again a speed reduction seemed to be the answer to what I thought was a loose gear door at that time. During the last 1000 ft of the approach, as speed was further reduced, right wing heavy indications were noted and overcome with aileron and rudder factors. Upon post flight inspection, a 9 ft by 1 ft section of the right trailing wing between the flap faring was found to have deformed/delaminated and cracked in places. Callback conversation with reporter revealed the following information. In response to callback, the reporter stated that his airline maintenance found that there was a defect in the manufacture of the wing trailing edge. Apparently, a bonding agent in sheet form is used to bond the wing skin to honeycomb structure that forms the core. A shield of some sort, similar to wax paper, is used to prevent the bonding sheet from acting before it is in it's proper place. Some of this shield material was not removed in the assembly procedure. This prevented the skin from bonding to the core. To the reporter's knowledge, this is a unique situation in this airline's fleet of this new aircraft. The reporter stated that he did not feel it to be necessary to inspect the wing in-flight as he thought that he had a landing gear door problem, similar to a previous occurrence. Several passengers noted the delamination problem, but no one told a crew member what they had seen until the aircraft was at the gate.

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Original NASA ASRS Text

Title: AN MLG EXPERIENCED A DELAMINATION OF PART OF THE TRAILING EDGE OF ONE OF THE WINGS IN FLT (A PIECE 1 FT BY 9 FT) CAUSING A VIBRATION AND SOME CTL PROBLEMS.

Narrative: DURING CRUISE FLT A SLIGHT R WING HVY INDICATION WAS NOTED AND WAS EASILY CORRECTED BY THE AUTOPLT. NEXT INDICATION APPEARED DURING DSCNT BY A NOISE/VIBRATION THAT WAS CORRECTED BY A SLIGHT SPD REDUCTION AND PITCH CHANGE. OBVIOUS PROBLEM DID NOT OCCUR UNTIL FINAL WHEN GEAR WAS LOWERED AND A VERY LOUD AND OBVIOUS VIBRATION WAS FELT. ONCE AGAIN A SPD REDUCTION SEEMED TO BE THE ANSWER TO WHAT I THOUGHT WAS A LOOSE GEAR DOOR AT THAT TIME. DURING THE LAST 1000 FT OF THE APCH, AS SPD WAS FURTHER REDUCED, R WING HVY INDICATIONS WERE NOTED AND OVERCOME WITH AILERON AND RUDDER FACTORS. UPON POST FLT INSPECTION, A 9 FT BY 1 FT SECTION OF THE R TRAILING WING BTWN THE FLAP FARING WAS FOUND TO HAVE DEFORMED/DELAMINATED AND CRACKED IN PLACES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO. IN RESPONSE TO CALLBACK, THE RPTR STATED THAT HIS AIRLINE MAINT FOUND THAT THERE WAS A DEFECT IN THE MANUFACTURE OF THE WING TRAILING EDGE. APPARENTLY, A BONDING AGENT IN SHEET FORM IS USED TO BOND THE WING SKIN TO HONEYCOMB STRUCTURE THAT FORMS THE CORE. A SHIELD OF SOME SORT, SIMILAR TO WAX PAPER, IS USED TO PREVENT THE BONDING SHEET FROM ACTING BEFORE IT IS IN IT'S PROPER PLACE. SOME OF THIS SHIELD MATERIAL WAS NOT REMOVED IN THE ASSEMBLY PROC. THIS PREVENTED THE SKIN FROM BONDING TO THE CORE. TO THE RPTR'S KNOWLEDGE, THIS IS A UNIQUE SITUATION IN THIS AIRLINE'S FLEET OF THIS NEW ACFT. THE RPTR STATED THAT HE DID NOT FEEL IT TO BE NECESSARY TO INSPECT THE WING INFLT AS HE THOUGHT THAT HE HAD A LNDG GEAR DOOR PROBLEM, SIMILAR TO A PREVIOUS OCCURRENCE. SEVERAL PAXS NOTED THE DELAMINATION PROBLEM, BUT NO ONE TOLD A CREW MEMBER WHAT THEY HAD SEEN UNTIL THE ACFT WAS AT THE GATE.

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.