Narrative:

Leg: bwi - mco. I was þprogrammerþ of the FMC this leg. Coming down from bwi, I programmed the route as filed, bringing us to chs on J121. After chs, I typed in þJ79,þ then, mistakenly, þonm.þ seeing my error, I typed in þomnþ (ormond beach), and brought it up to replace þonmþ (I didnþt want to go to socorro, NM!). That fixed (so I thought), I continued to type in the þbitho 6þ arrival to runway 18R at orlando. Everything in the þboxþ looked shipshape, so I activated the flight plan. I did not xchk against the flight plan, waypoint-by-waypoint, verifying the þlegs pageþ and flight plan agreed. I þknewþ I had carefully entered the route of flight, leg-by-leg, in the þrte pageþ -- iþd even caught the þonmþ (socorro) þomnþ (ormond beach) mistake, so I knew I had put it in right. So I thought...what I didnþt realize was, the computer had dumped þJ79þ on me - - when I mistakenly typed in þonmþ (it knew J79 does not lead to socorro, NM). When I typed over the correct fix, þomn,þ the computer made it direct, eliminating J79 and its crucial fix þstary,þ which puts a bend in the jetway to avoid W-137/W157A. Sure enough, after chs, the LNAV headed us towards omn direct. It was the captþs leg, and he knew I was a sharp young computer whiz, so he didnþt doubt the accuracy of the programming. About 45 mi ssw of chs, ZJX calls up and gives us a fairly nonchalant þ20 degree right steer to avoid restr airspace.þ captain says, þwhatþs up?þ I backtrack, figure out my error (and the computerþs logic) on route 2 page (recreating my programming sequence, including the onm/omn mis- entry/correction that caused J79 to dump out, and þdirect omnþ to take its place. Lessons learned: 1) always xchk the route of flight on the legs page against the flight plan. 2) never trust the logic of the FMC computer -- it does what it does, and can screw you. 3) never trust the programming of your first officer (captain) -- he may have been þtrickedþ by the FMC!

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Original NASA ASRS Text

Title: FO OF ACR LGT ACFT INADVERTENTLY MISPROGRAMMED THE FMC RESULTING IN MISSING AN IMPORTANT TURNING POINT TO AVOID A WARNING AIRSPACE AREA. ATC INTERVENED AND þSAVED THE DAY.þ

Narrative: LEG: BWI - MCO. I WAS þPROGRAMMERþ OF THE FMC THIS LEG. COMING DOWN FROM BWI, I PROGRAMMED THE RTE AS FILED, BRINGING US TO CHS ON J121. AFTER CHS, I TYPED IN þJ79,þ THEN, MISTAKENLY, þONM.þ SEEING MY ERROR, I TYPED IN þOMNþ (ORMOND BEACH), AND BROUGHT IT UP TO REPLACE þONMþ (I DIDNþT WANT TO GO TO SOCORRO, NM!). THAT FIXED (SO I THOUGHT), I CONTINUED TO TYPE IN THE þBITHO 6þ ARR TO RWY 18R AT ORLANDO. EVERYTHING IN THE þBOXþ LOOKED SHIPSHAPE, SO I ACTIVATED THE FLT PLAN. I DID NOT XCHK AGAINST THE FLT PLAN, WAYPOINT-BY-WAYPOINT, VERIFYING THE þLEGS PAGEþ AND FLT PLAN AGREED. I þKNEWþ I HAD CAREFULLY ENTERED THE RTE OF FLT, LEG-BY-LEG, IN THE þRTE PAGEþ -- IþD EVEN CAUGHT THE þONMþ (SOCORRO) þOMNþ (ORMOND BEACH) MISTAKE, SO I KNEW I HAD PUT IT IN RIGHT. SO I THOUGHT...WHAT I DIDNþT REALIZE WAS, THE COMPUTER HAD DUMPED þJ79þ ON ME - - WHEN I MISTAKENLY TYPED IN þONMþ (IT KNEW J79 DOES NOT LEAD TO SOCORRO, NM). WHEN I TYPED OVER THE CORRECT FIX, þOMN,þ THE COMPUTER MADE IT DIRECT, ELIMINATING J79 AND ITS CRUCIAL FIX þSTARY,þ WHICH PUTS A BEND IN THE JETWAY TO AVOID W-137/W157A. SURE ENOUGH, AFTER CHS, THE LNAV HEADED US TOWARDS OMN DIRECT. IT WAS THE CAPTþS LEG, AND HE KNEW I WAS A SHARP YOUNG COMPUTER WHIZ, SO HE DIDNþT DOUBT THE ACCURACY OF THE PROGRAMMING. ABOUT 45 MI SSW OF CHS, ZJX CALLS UP AND GIVES US A FAIRLY NONCHALANT þ20 DEG R STEER TO AVOID RESTR AIRSPACE.þ CAPT SAYS, þWHATþS UP?þ I BACKTRACK, FIGURE OUT MY ERROR (AND THE COMPUTERþS LOGIC) ON RTE 2 PAGE (RECREATING MY PROGRAMMING SEQUENCE, INCLUDING THE ONM/OMN MIS- ENTRY/CORRECTION THAT CAUSED J79 TO DUMP OUT, AND þDIRECT OMNþ TO TAKE ITS PLACE. LESSONS LEARNED: 1) ALWAYS XCHK THE RTE OF FLT ON THE LEGS PAGE AGAINST THE FLT PLAN. 2) NEVER TRUST THE LOGIC OF THE FMC COMPUTER -- IT DOES WHAT IT DOES, AND CAN SCREW YOU. 3) NEVER TRUST THE PROGRAMMING OF YOUR FO (CAPT) -- HE MAY HAVE BEEN þTRICKEDþ BY THE FMC!

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.