Narrative:

This flight was a scheduled flight from iah-tpa. The route filed was scholes 5 departure to leeville, J86 to blond 2 arrival tpa. Shortly after takeoff we took up a 090 degree heading to deviate around a small thunderstorm. We then took an assigned heading of 120 degrees at 4000 ft from departure. Departure then cleared us to 15000 ft. After handoff to center we were given a heading of 140 degrees to join the 083 degree radial off the vuh VOR, which is the transition route. We were then handed off to another sector and given a heading of 130 degrees and a climb to FL230. A short time later we were given a heading back to 140 degrees. At this point both pilots must have mistakenly understood this clearance. The event wording is hard to remember, but the VOR capture mode was armed by the first officer who was flying. From this point several mins passed before the 083 degree radial from vuh was captured. Shortly after joining the radial, ZHU controller asked our heading. We were given an immediate right turn to 170 degrees followed by instruction to maintain altitude. We were at FL210. We then got a TCASII RA command to descend followed by clearance to descend to FL200. I acquired visual with the other aircraft which passed above and to the left. We were then cleared on course. Even though I thought I was cleared to join the VOR course I should have verified it. Though it is not the controller's duty to monitor our clearance, had she given us a right turn instead of asking about our heading, we may have avoided the reduced separation.

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Original NASA ASRS Text

Title: MD80 FLC HAS CLRNC CONFUSION AND MISTAKENLY INTERCEPTS VOR RADIAL CAUSING TCASII RA. CTLR INTERVENES, BUT TOO LATE TO AVOID THE RA.

Narrative: THIS FLT WAS A SCHEDULED FLT FROM IAH-TPA. THE RTE FILED WAS SCHOLES 5 DEP TO LEEVILLE, J86 TO BLOND 2 ARR TPA. SHORTLY AFTER TKOF WE TOOK UP A 090 DEG HDG TO DEVIATE AROUND A SMALL TSTM. WE THEN TOOK AN ASSIGNED HDG OF 120 DEGS AT 4000 FT FROM DEP. DEP THEN CLRED US TO 15000 FT. AFTER HDOF TO CTR WE WERE GIVEN A HDG OF 140 DEGS TO JOIN THE 083 DEG RADIAL OFF THE VUH VOR, WHICH IS THE TRANSITION RTE. WE WERE THEN HANDED OFF TO ANOTHER SECTOR AND GIVEN A HDG OF 130 DEGS AND A CLB TO FL230. A SHORT TIME LATER WE WERE GIVEN A HDG BACK TO 140 DEGS. AT THIS POINT BOTH PLTS MUST HAVE MISTAKENLY UNDERSTOOD THIS CLRNC. THE EVENT WORDING IS HARD TO REMEMBER, BUT THE VOR CAPTURE MODE WAS ARMED BY THE FO WHO WAS FLYING. FROM THIS POINT SEVERAL MINS PASSED BEFORE THE 083 DEG RADIAL FROM VUH WAS CAPTURED. SHORTLY AFTER JOINING THE RADIAL, ZHU CTLR ASKED OUR HDG. WE WERE GIVEN AN IMMEDIATE R TURN TO 170 DEGS FOLLOWED BY INSTRUCTION TO MAINTAIN ALT. WE WERE AT FL210. WE THEN GOT A TCASII RA COMMAND TO DSND FOLLOWED BY CLRNC TO DSND TO FL200. I ACQUIRED VISUAL WITH THE OTHER ACFT WHICH PASSED ABOVE AND TO THE L. WE WERE THEN CLRED ON COURSE. EVEN THOUGH I THOUGHT I WAS CLRED TO JOIN THE VOR COURSE I SHOULD HAVE VERIFIED IT. THOUGH IT IS NOT THE CTLR'S DUTY TO MONITOR OUR CLRNC, HAD SHE GIVEN US A R TURN INSTEAD OF ASKING ABOUT OUR HDG, WE MAY HAVE AVOIDED THE REDUCED SEPARATION.

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.