Narrative:

ATC facility: ZFW. Location: between bleco and zemma on TEX7 departure. Departure as PNF, I noted during climb that aircraft did not track course properly after passing bleco en route to zeema even though all indications to the crew were that it should. Right autoplt was engaged with LNAV status indicating engaged. Captain's range knob was set high which masks the deviation. PNF was engaged in HF operational check passing FL300. PNF noticed the deviation when ATC called requesting an immediate turn. Contributing factors: 1) possible mechanical discrepancy with right autoplt. 2) captain's EFIS range knob set too high. 3) PNF engaged in HF operational check during track change. 4) no TCASII warning. Supplemental information from acn 595551: r-hand autoplt engaged LNAV indicated green (status engaged) navigation display on 80 mi scale. Did not notice that aircraft was not tracking course, due to range selected, until west of intended course. Noticed the display at the same time was given a turn by ATC. Did not receive any alert on TCASII. Event was recorded in aircraft logbook. R-hand autoplt performed normally and could not duplicate occurrence. Called ATC after flight and was informed that loss of separation occurred. Within 4.46 mi and 400 ft of other air carrier jet.

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Original NASA ASRS Text

Title: A B767 MAINT TEST FLT CREW EXPERIENCES A POTENTIAL CONFLICT DURING CLB WHEN THE FMS FAILS TO MAINTAIN THE DESIRED TRACK ON THE TEX7 DEP PROC FROM AFW, TX.

Narrative: ATC FACILITY: ZFW. LOCATION: BTWN BLECO AND ZEMMA ON TEX7 DEP. DEP AS PNF, I NOTED DURING CLB THAT ACFT DID NOT TRACK COURSE PROPERLY AFTER PASSING BLECO ENRTE TO ZEEMA EVEN THOUGH ALL INDICATIONS TO THE CREW WERE THAT IT SHOULD. R AUTOPLT WAS ENGAGED WITH LNAV STATUS INDICATING ENGAGED. CAPT'S RANGE KNOB WAS SET HIGH WHICH MASKS THE DEV. PNF WAS ENGAGED IN HF OPERATIONAL CHK PASSING FL300. PNF NOTICED THE DEV WHEN ATC CALLED REQUESTING AN IMMEDIATE TURN. CONTRIBUTING FACTORS: 1) POSSIBLE MECHANICAL DISCREPANCY WITH R AUTOPLT. 2) CAPT'S EFIS RANGE KNOB SET TOO HIGH. 3) PNF ENGAGED IN HF OPERATIONAL CHK DURING TRACK CHANGE. 4) NO TCASII WARNING. SUPPLEMENTAL INFO FROM ACN 595551: R-HAND AUTOPLT ENGAGED LNAV INDICATED GREEN (STATUS ENGAGED) NAV DISPLAY ON 80 MI SCALE. DID NOT NOTICE THAT ACFT WAS NOT TRACKING COURSE, DUE TO RANGE SELECTED, UNTIL W OF INTENDED COURSE. NOTICED THE DISPLAY AT THE SAME TIME WAS GIVEN A TURN BY ATC. DID NOT RECEIVE ANY ALERT ON TCASII. EVENT WAS RECORDED IN ACFT LOGBOOK. R-HAND AUTOPLT PERFORMED NORMALLY AND COULD NOT DUPLICATE OCCURRENCE. CALLED ATC AFTER FLT AND WAS INFORMED THAT LOSS OF SEPARATION OCCURRED. WITHIN 4.46 MI AND 400 FT OF OTHER ACR JET.

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.