Narrative:

This crew flew together for 5 legs in same aircraft. On leg 3 (phx-lax), the FMC created a route discontinuity at tejay intersection while flying the pdz arrival into lax. This was caught by the crew airborne in cruise. The route as programmed looked good on deck. Leg 5 was the exact same route as 3 -- this time the FMC created a route discontinuity at buckeye on the SID out of phx. It occurred just after leveloff at night/IMC. Having already got a problem with the FMC, this crew verified the route prior to departure and it was ok -- no discontinuities. However, once at buckeye, we flew a heading of approximately 260 degrees flying the J4 as depicted on the SID. We were queried by center as to our intentions, and given a heading of 290 degrees to join J4. At this time we noticed the discontinuity. Several lessons for me as pilot and crew: 1) I attributed the FMC errors to programming by me. New to aircraft. I believe there was something wrong with the FMC. We wrote it up at lax. However, once the captain gave the route the ok, I was not checking the FMC consistently on departure, thus was caught unaware. I had a different page on the FMC itself, depicting winds aloft and times to various points en route. 2) I should have noticed the incorrect heading out of buckeye. The error was approximately 30 degrees off course, and I did not notice the deviation till center said something. 3) as the PF, I assumed the captain would take care of everything else. I didn't/failed to back him up -- poor crew coordination. This really boils down to training/crew coordination. We blindly followed 'the yellow brick road.' had center not said something right after buckeye, I don't know how far we would have flown -- probably till we hit the R2306/08 or R2507. Thank goodness center had demonstrated some good crew coordination skills.

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Original NASA ASRS Text

Title: A B737-300 CREW HAD TRACK DEV IN ZAB CLASS A AIRSPACE.

Narrative: THIS CREW FLEW TOGETHER FOR 5 LEGS IN SAME ACFT. ON LEG 3 (PHX-LAX), THE FMC CREATED A RTE DISCONTINUITY AT TEJAY INTXN WHILE FLYING THE PDZ ARR INTO LAX. THIS WAS CAUGHT BY THE CREW AIRBORNE IN CRUISE. THE RTE AS PROGRAMMED LOOKED GOOD ON DECK. LEG 5 WAS THE EXACT SAME RTE AS 3 -- THIS TIME THE FMC CREATED A RTE DISCONTINUITY AT BUCKEYE ON THE SID OUT OF PHX. IT OCCURRED JUST AFTER LEVELOFF AT NIGHT/IMC. HAVING ALREADY GOT A PROB WITH THE FMC, THIS CREW VERIFIED THE RTE PRIOR TO DEP AND IT WAS OK -- NO DISCONTINUITIES. HOWEVER, ONCE AT BUCKEYE, WE FLEW A HDG OF APPROX 260 DEGS FLYING THE J4 AS DEPICTED ON THE SID. WE WERE QUERIED BY CTR AS TO OUR INTENTIONS, AND GIVEN A HDG OF 290 DEGS TO JOIN J4. AT THIS TIME WE NOTICED THE DISCONTINUITY. SEVERAL LESSONS FOR ME AS PLT AND CREW: 1) I ATTRIBUTED THE FMC ERRORS TO PROGRAMMING BY ME. NEW TO ACFT. I BELIEVE THERE WAS SOMETHING WRONG WITH THE FMC. WE WROTE IT UP AT LAX. HOWEVER, ONCE THE CAPT GAVE THE RTE THE OK, I WAS NOT CHKING THE FMC CONSISTENTLY ON DEP, THUS WAS CAUGHT UNAWARE. I HAD A DIFFERENT PAGE ON THE FMC ITSELF, DEPICTING WINDS ALOFT AND TIMES TO VARIOUS POINTS ENRTE. 2) I SHOULD HAVE NOTICED THE INCORRECT HDG OUT OF BUCKEYE. THE ERROR WAS APPROX 30 DEGS OFF COURSE, AND I DID NOT NOTICE THE DEV TILL CTR SAID SOMETHING. 3) AS THE PF, I ASSUMED THE CAPT WOULD TAKE CARE OF EVERYTHING ELSE. I DIDN'T/FAILED TO BACK HIM UP -- POOR CREW COORD. THIS REALLY BOILS DOWN TO TRAINING/CREW COORD. WE BLINDLY FOLLOWED 'THE YELLOW BRICK ROAD.' HAD CTR NOT SAID SOMETHING RIGHT AFTER BUCKEYE, I DON'T KNOW HOW FAR WE WOULD HAVE FLOWN -- PROBABLY TILL WE HIT THE R2306/08 OR R2507. THANK GOODNESS CTR HAD DEMONSTRATED SOME GOOD CREW COORD SKILLS.

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.