WING FLAPS CANNOT BE RETRACTED AFTER TKOF BECAUSE OF WHEEL CHOCK LEFT IN WING ROOT AREA BY MAINT.

Narrative

A WING PANEL HAD DELAMINATED. LOCATION OF THE PANEL WAS ON THE TOP OF THE L WING; MOST INBOARD AND AFT. THE PANEL WAS REMOVED ON THE SHIFT BEFORE. THE OTHER SHEET METAL MECH INVOLVED DRILLED UP THE PANEL AND WAS READY FOR INSTALLATION WHEN I ARRIVED. THE MEANS FOR ATTACHMENT OF THIS PANEL IS BY RIVETING TO SECONDARY STRUCTURE OF THE WING. ACCESS FOR BUCKING OF THE RIVETS IS ON THE BOTTOM OF THE WING JUST ABOVE AND AFT OF THE MAIN LNDG GEAR. THE FLAPS AT THAT TIME WERE 15 DEGS. AT THIS SETTING; THE BUTTE DOOR WHICH IS DIRECTLY BELOW THIS WING PANEL IS TOTALLY OBSCURING ALL ACCESS. WHAT I AND MY PARTNER DID WAS PULL THE BUTTE DOOR DOWN; WHICH IS SPRING LOADED; AND INSERTED A WHEEL CHOCK TO HOLD THIS DOOR OPEN WHILE THE RIVETING WAS BEING ACCOMPLISHED. THE JOB WAS COMPLETED SHORTLY AFTER. WE HAD AN INSPECTOR INSPECT THE JOB. THE INSPECTOR AND THE OTHER MECH SIGNED ALL THE PAPERWORK OFF. THE WHEEL CHOCK WAS NEVER REMOVED FROM THE BUTTE DOOR AREA. SUPPLEMENTAL INFO FROM ACN 233366: WHEN WE TRIED TO RETRACT FLAPS ON CLBOUT; THE FLAPS STARTED TO SPLIT AT 5 DEGS WITH THE L SIDE HANGING UP. WE PUT FLAPS BACK TO 11 DEGS AND TRIED TO RETRACT THEM AGAIN WITH THE SAME RESULT. CALLED MAINT AND THEY SUGGESTED LOWERING GEAR AND PUTTING FLAPS ALL THE WAY OUT (TO 40 DEGS) WHICH WE DID. FLAPS THEN CAME ALL THE WAY BACK UP; BUT THE L MAIN THEN INDICATED UNSAFE; SO WE RETURNED TO DEN WITHOUT INCIDENT. DURING PREFLT; THE FLAPS WERE DROOPING A FEW DEGS; BUT THE AREA WHERE THE DAMAGE OCCURRED WAS COVERED. WITHOUT FULLY EXTENDING THE FLAP SYS TO GAIN ACCESS; IT WOULD BE DIFFICULT TO SEE ANY FOREIGN OBJECTS IN THAT AREA. I DID THE PREFLT AND SHOULD HAVE QUESTIONED WHY THE FLAPS WOULD BE DROOPING SO SOON AFTER ARRIVING AT THE GATE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THIS MECH WAS THE ONLY SUCCESSFUL CALLBACK. HE WAS ASKED IF HE KNEW WHY THE ACFT HAD A GEAR UNSAFE LIGHT WHEN THE FLAPS WERE FINALLY FULLY RETRACTED. HE HAD NO IDEA. HE HAS ALREADY BEEN GIVEN TIME OFF WITHOUT PAY BY HIS COMPANY AND THE FAA IS THREATENING SUSPENDING HIS LICENSE FOR SOME PERIOD OF TIME.