Narrative:

I was in ZZZ to replace an outboard flap; inboard trailing edge panel. I noted wrong part number was delivered. Worked with engineering to rectify part number issues. Got verbal saying it was interchangeable; difference was in the inboard end rib of panel. Differences visually noticeable; took picture of area with notes; submitted to engineering. Got reply back saying it was a bonded channel. Installed trailing edge; got engineering change for use interchangeability and signed off paperwork along with quality control inspection. Returned to YYY that day. Aircraft returned to service. When I got back to work; I pulled up a drawing to do a gut check on some information received on channels and found fasteners in drawing not installed on trailing edge rib channels. I notified line maintenance supervisor; maintenance control; and engineering. Appropriate actions were taken by all. Engineering contacted bombardier and has since got a re-dispatch for aircraft for return to service as is. Just did a self-check and didn't get a good feeling of the answer I got from engineering about pilot holes in rib channels and did a little more research and found fasteners to be missing in channels. Notified maintenance supervisor; maintenance control; which swapped out aircraft with spare; and engineering contacted for more information. Lack of documentation on interchangeability as to what is required when changing parts and conflicting drawings. When dealing with interchangeability issues; ensure all documentation on differences accompany the engineering change for proper install of new part. Not just a statement saying they are interchangeable.

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Original NASA ASRS Text

Title: A MECHANIC ON A FIELD TRIP REPLACING AN OUTBOARD FLAP; INBOARD TRAILING EDGE PANEL ON A DEHAVILLAND DHC-8-400 ACFT; NOTES THE VISUAL DIFFERENCES FROM THE REMOVED PANEL. ENGINEERING STILL APPROVED THE USE OF PANEL.

Narrative: I WAS IN ZZZ TO REPLACE AN OUTBOARD FLAP; INBOARD TRAILING EDGE PANEL. I NOTED WRONG PART NUMBER WAS DELIVERED. WORKED WITH ENGINEERING TO RECTIFY PART NUMBER ISSUES. GOT VERBAL SAYING IT WAS INTERCHANGEABLE; DIFFERENCE WAS IN THE INBOARD END RIB OF PANEL. DIFFERENCES VISUALLY NOTICEABLE; TOOK PICTURE OF AREA WITH NOTES; SUBMITTED TO ENGINEERING. GOT REPLY BACK SAYING IT WAS A BONDED CHANNEL. INSTALLED TRAILING EDGE; GOT ENGINEERING CHANGE FOR USE INTERCHANGEABILITY AND SIGNED OFF PAPERWORK ALONG WITH QUALITY CTL INSPECTION. RETURNED TO YYY THAT DAY. ACFT RETURNED TO SVC. WHEN I GOT BACK TO WORK; I PULLED UP A DRAWING TO DO A GUT CHK ON SOME INFO RECEIVED ON CHANNELS AND FOUND FASTENERS IN DRAWING NOT INSTALLED ON TRAILING EDGE RIB CHANNELS. I NOTIFIED LINE MAINT SUPVR; MAINT CTL; AND ENGINEERING. APPROPRIATE ACTIONS WERE TAKEN BY ALL. ENGINEERING CONTACTED BOMBARDIER AND HAS SINCE GOT A RE-DISPATCH FOR ACFT FOR RETURN TO SVC AS IS. JUST DID A SELF-CHK AND DIDN'T GET A GOOD FEELING OF THE ANSWER I GOT FROM ENGINEERING ABOUT PILOT HOLES IN RIB CHANNELS AND DID A LITTLE MORE RESEARCH AND FOUND FASTENERS TO BE MISSING IN CHANNELS. NOTIFIED MAINT SUPVR; MAINT CTL; WHICH SWAPPED OUT ACFT WITH SPARE; AND ENGINEERING CONTACTED FOR MORE INFO. LACK OF DOCUMENTATION ON INTERCHANGEABILITY AS TO WHAT IS REQUIRED WHEN CHANGING PARTS AND CONFLICTING DRAWINGS. WHEN DEALING WITH INTERCHANGEABILITY ISSUES; ENSURE ALL DOCUMENTATION ON DIFFERENCES ACCOMPANY THE ENGINEERING CHANGE FOR PROPER INSTALL OF NEW PART. NOT JUST A STATEMENT SAYING THEY ARE INTERCHANGEABLE.

Data retrieved from NASA's ASRS site as of May 2009 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.