Narrative:

Preflight inspection revealed a right inboard flap panel crooked and binding in its flap track. Maintenance inspected flap and was hesitant to make any correction until flap was lowered and retracted several times. I had to point out that the flap was binding about the last 5 degrees of movement on retraction. This is a recurring problem on the E12. Callback conversation with reporter revealed the following information: after flap retraction, an inboard flap has trailed as much as 1 inch. This becomes a serious problem when this misalignment wears out the flap rollers and tracks. The misalignment referenced is a result of not matching the original flap with the original airplane during maintenance. The flaps on the early prototype were basically handmade, and since, have been developed from new jigs. The fit can be so poor when the flaps are not matched with the original aircraft that the matching flap has to be hunted down and an additional airplane grounded, while the flaps are exchanged. This reporter recommends that operators of the early and later model E120's number and label each flap so that they are kept with the airplane while the airplane is in maintenance. Reporter contends that any flap asymmetry beyond 7 degrees will cause the computer to shut down the flap extension, but why let this problem get to that point?

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Original NASA ASRS Text

Title: THIS RPTR HAS EXPERIENCED A RECURRING PROB WITH THE FLAP EXTENSION AND RETRACTION AND DISCUSSES THE REASON WHY THE PROB OCCURRED.

Narrative: PREFLT INSPECTION REVEALED A R INBOARD FLAP PANEL CROOKED AND BINDING IN ITS FLAP TRACK. MAINT INSPECTED FLAP AND WAS HESITANT TO MAKE ANY CORRECTION UNTIL FLAP WAS LOWERED AND RETRACTED SEVERAL TIMES. I HAD TO POINT OUT THAT THE FLAP WAS BINDING ABOUT THE LAST 5 DEGS OF MOVEMENT ON RETRACTION. THIS IS A RECURRING PROB ON THE E12. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: AFTER FLAP RETRACTION, AN INBOARD FLAP HAS TRAILED AS MUCH AS 1 INCH. THIS BECOMES A SERIOUS PROB WHEN THIS MISALIGNMENT WEARS OUT THE FLAP ROLLERS AND TRACKS. THE MISALIGNMENT REFED IS A RESULT OF NOT MATCHING THE ORIGINAL FLAP WITH THE ORIGINAL AIRPLANE DURING MAINT. THE FLAPS ON THE EARLY PROTOTYPE WERE BASICALLY HANDMADE, AND SINCE, HAVE BEEN DEVELOPED FROM NEW JIGS. THE FIT CAN BE SO POOR WHEN THE FLAPS ARE NOT MATCHED WITH THE ORIGINAL ACFT THAT THE MATCHING FLAP HAS TO BE HUNTED DOWN AND AN ADDITIONAL AIRPLANE GROUNDED, WHILE THE FLAPS ARE EXCHANGED. THIS RPTR RECOMMENDS THAT OPERATORS OF THE EARLY AND LATER MODEL E120'S NUMBER AND LABEL EACH FLAP SO THAT THEY ARE KEPT WITH THE AIRPLANE WHILE THE AIRPLANE IS IN MAINT. RPTR CONTENDS THAT ANY FLAP ASYMMETRY BEYOND 7 DEGS WILL CAUSE THE COMPUTER TO SHUT DOWN THE FLAP EXTENSION, BUT WHY LET THIS PROB GET TO THAT POINT?

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.