Narrative:

On aircraft twice in two weeks, the left aileron panel between aileron and rear spar broke causing major damage in both incidents. (There is an ad note pertaining to this problem) I bring this incident up to reflect on how it was discovered. Both of these incidents were reported by passengers. The cockpit crew neither felt nor observed anything amiss with the aircraft. Had this not been a 'fly by wire' aircraft a vibration would have been felt on the control wheel and reported, thus minimizing the damage and increasing the safety factor. However because of the 'fly by wire' the computers compensated for the flutter and vibration that occurred and did it so well the cockpit crew knew nothing about what was happening to their aircraft. There would be no warning until a complete failure occurred and then a possible catastrophic event could occur. I believe this could be prevented if we would reprogram the onboard computers utilizing the existing rvdt's that report to the onboard computers. When the computers sense abnormal movement or vibration a warning would be sent to the cockpit. I believe that this would bring to the attention of the crew and would be checked out and repaired before the damage would reach a major stage. Callback conversation with reporter revealed the following information: the reporter stated this airplane xyz had two reports of passengers observing the left aileron to wing upper panel vibrating and fluttering which incurred damage to the aileron and the panel. The reporter said the first report damaged the panel and broke a bracket and two weeks later the aileron and panel was cracked. The reporter stated the carrier had three other events of this panel vibration or flutter on other airplanes in this fleet. The reporter said an airworthiness directive has been issued by the FAA to install heavier nutplates and fasteners on the panel. The reporter stated the flight crews were unaware of the vibration as no feedback was felt in the control handle and no flight control warning was annunciated. The reporter said it may be possible to modify the flight control units to trigger a flight control warning when a control surface or fairing panel is fluttering or vibrating.

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Original NASA ASRS Text

Title: AN AIRBUS 319 IN FLT HAD PASSENGERS RPT VIBRATION OR FLUTTER ON LEFT AILERON TO WING UPPER FAIRING PANEL WHICH INCURRED DAMAGE TO THE AILERON AND PANEL. FLC NOT AWARE OF VIBRATION OR FLUTTER.

Narrative: ON ACFT TWICE IN TWO WEEKS, THE L AILERON PANEL BTWN AILERON AND REAR SPAR BROKE CAUSING MAJOR DAMAGE IN BOTH INCIDENTS. (THERE IS AN AD NOTE PERTAINING TO THIS PROB) I BRING THIS INCIDENT UP TO REFLECT ON HOW IT WAS DISCOVERED. BOTH OF THESE INCIDENTS WERE RPTED BY PASSENGERS. THE COCKPIT CREW NEITHER FELT NOR OBSERVED ANYTHING AMISS WITH THE ACFT. HAD THIS NOT BEEN A 'FLY BY WIRE' ACFT A VIBRATION WOULD HAVE BEEN FELT ON THE CTL WHEEL AND RPTED, THUS MINIMIZING THE DAMAGE AND INCREASING THE SAFETY FACTOR. HOWEVER BECAUSE OF THE 'FLY BY WIRE' THE COMPUTERS COMPENSATED FOR THE FLUTTER AND VIBRATION THAT OCCURRED AND DID IT SO WELL THE COCKPIT CREW KNEW NOTHING ABOUT WHAT WAS HAPPENING TO THEIR ACFT. THERE WOULD BE NO WARNING UNTIL A COMPLETE FAILURE OCCURRED AND THEN A POSSIBLE CATASTROPHIC EVENT COULD OCCUR. I BELIEVE THIS COULD BE PREVENTED IF WE WOULD REPROGRAM THE ONBOARD COMPUTERS UTILIZING THE EXISTING RVDT'S THAT RPT TO THE ONBOARD COMPUTERS. WHEN THE COMPUTERS SENSE ABNORMAL MOVEMENT OR VIBRATION A WARNING WOULD BE SENT TO THE COCKPIT. I BELIEVE THAT THIS WOULD BRING TO THE ATTENTION OF THE CREW AND WOULD BE CHKED OUT AND REPAIRED BEFORE THE DAMAGE WOULD REACH A MAJOR STAGE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THIS AIRPLANE XYZ HAD TWO RPTS OF PASSENGERS OBSERVING THE L AILERON TO WING UPPER PANEL VIBRATING AND FLUTTERING WHICH INCURRED DAMAGE TO THE AILERON AND THE PANEL. THE RPTR SAID THE FIRST RPT DAMAGED THE PANEL AND BROKE A BRACKET AND TWO WEEKS LATER THE AILERON AND PANEL WAS CRACKED. THE RPTR STATED THE CARRIER HAD THREE OTHER EVENTS OF THIS PANEL VIBRATION OR FLUTTER ON OTHER AIRPLANES IN THIS FLEET. THE RPTR SAID AN AIRWORTHINESS DIRECTIVE HAS BEEN ISSUED BY THE FAA TO INSTALL HEAVIER NUTPLATES AND FASTENERS ON THE PANEL. THE RPTR STATED THE FLIGHT CREWS WERE UNAWARE OF THE VIBRATION AS NO FEEDBACK WAS FELT IN THE CTL HANDLE AND NO FLT CTL WARNING WAS ANNUNCIATED. THE RPTR SAID IT MAY BE POSSIBLE TO MODIFY THE FLT CTL UNITS TO TRIGGER A FLT CTL WARNING WHEN A CTL SURFACE OR FAIRING PANEL IS FLUTTERING OR VIBRATING.

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.