AN MD88 WAS DISPATCHED IN NON COMPLIANCE WITH AN INCORRECT T-FITTING CAPPED OFF FOR APU DUCT BURNOUT PROC.

Narrative

ON JAN/THU/03; ACFT X WAS IN NEED OF AN OP XXXX; WHICH IS A DUCT BURNOUT; DUE TO CONTAMINATION OF THE APU AIR INTAKE COMPARTMENT. WORK ON THE ACFT HAD ALREADY BEEN STARTED BY THE LATE NIGHT SHIFT AND THE ACFT WAS TURNED OVER TO DAY SHIFT WITHOUT A FACE-TO-FACE. UPON REVIEWING THE PAPERWORK; ITEMS I AND #2 HAD ALREADY BEEN SIGNED OFF BY THE LATE NIGHT SHIFT; BUT PRIOR TO PERFORMING THE DUCT BURNOUT; WE WENT OVER THESE ITEMS TO VERIFY THAT THE COCKPIT AND AUGMENTATION VALVE SETUP WERE IN THE READY POS AND VERIFIED AS IN COMPLIANCE. IN REVIEWING ITEM #2; I FOUND WHAT APPEARED TO BE THE T-FITTING LOCATED DOWNSTREAM OF THE AUGMENTATION VALVE; AS PER FIGURE 2 OF THE ATTACHED DETAILED INSTRUCTIONS. THE FITTING WS NOT DISCONNECTED OR CAPPED. I PROCEEDED TO DISCONNECT AND CAP THE FITTING. AN OP XXXX WAS RUN; RECONNECTED THE LINES AND CHKED FOR LEAKING. ALL SYS GO; ACFT RETURNED TO SVC. THE CAPS THAT WERE ALREADY INSTALLED BY LATE NIGHT SHIFT HAD NO FLAG IDENTS. THE ACTUAL T-FITTING THAT I CAPPED AND DISCONNECTED WAS NOT THE CORRECT FITTING. IN FACT THIS PARTICULAR FITTING IS NOT SHOWN AT ALL IN FIGURE 2. IN OBSERVING THE COMPARTMENT; THE T-FITTING THAT I CAPPED APPEARS TO BE THE ONE IN THE DIAGRAM. THERE IS NO INDICATION THAT THE FITTING IS IN REALITY LOCATED BEHIND THE 13-STAGE BLEED AIR MANIFOLD. SINCE THE STANDARD TESTING PROCS DO NOT REQUIRE BRINGING THE ACFT TO FULL PWR; THE OVERTEMP CONDITION WAS NOT DETECTED BEFORE THE ACFT WAS DISPATCHED. AS A RESULT; THE ACFT HAD AN AIR TURN-BACK DUE TO A L AND R OVERTEMP MESSAGE ON THE OVERHEAD AIR-CONDITIONING PANEL. WHEN THE ACFT RETURNED TO THE GATE; MAINT DETECTED THE CAPPED T-FITTING; REMOVED THE CAPS; RECONNECTED THE LINES AND RAN NECESSARY TESTS TO RETURN THE ACFT TO SVC.