|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1201 To 1800|
|Locale Reference||airport : zzz.airport|
|Altitude||msl single value : 15000|
|Controlling Facilities||tracon : zzz.tracon|
|Operator||common carrier : air carrier|
|Make Model Name||B737-500|
|Operating Under FAR Part||Part 121|
|Flight Phase||climbout : initial|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Experience||flight time last 90 days : 219|
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Experience||flight time last 90 days : 241|
flight time type : 2000
|Anomaly||conflict : airborne less severe|
non adherence : clearance
|Independent Detector||aircraft equipment : tcas|
other flight crewa
|Resolutory Action||controller : issued advisory|
flight crew : took precautionary avoidance action
|Miss Distance||vertical : 1000|
|Problem Areas||ATC Human Performance|
Flight Crew Human Performance
|Primary Problem||Flight Crew Human Performance|
We were being step climbed by departure due to traffic above us also departing to the south. While we were level at 11000 ft MSL; the conflicting traffic was pointed out to us at 16000 ft MSL; 2 O'clock position and about 10 mi. We saw the traffic and reported it in sight. Departure then instructed us to maintain visual and climb to FL230. Departure also told us the traffic would be turning to a parallel course. The first officer (PF) continued the climb. As I watched the traffic I noticed it was not moving in the windscreen (ie; would be a conflict if something didn't change). Departure then informed us the traffic would cross right to left ahead of us. As the traffic was still not moving in the windscreen; I told the PF to slow the climb. The PF did not slow the climb as he was planning to climb above the traffic. I reminded him that we were to maintain a visual and that we would lose the other aircraft under the nose if we continued the climb. The PF then reversed his climb and we began to turn behind the traffic with ATC's concurrence. As the PF arrested his climb and began to descend and turn behind and below the traffic; we got a climb RA. Our aircraft vector was already behind and below the traffic and to comply with the TA/RA climb command would have been the wrong action. As the TCAS caught up with our aircraft vector; it directed a descent which we were already in. We passed behind and below the aircraft with 1000 ft altitude separation. The remainder of the flight was uneventful. I could have been more assertive in my directive comments to the PF. Departure should have ensured that our course would in fact parallel the other aircraft's course. Supplemental information from acn 764272: while climbing out on the departure we were given traffic at our 2 O'clock position and were told that he was paralleling our course. We called him in sight. We were given instructions to maintain visual contact and climb from 11000 ft to FL230. The first officer (me) was flying at the time. We were light (32 passenger) and I began the climb. In the climb; the captain noticed that the other aircraft was stationary in the windscreen (converging course) and directed that I leveloff. At the same time; the controller stated that the traffic would now be moving from right to left. At that point I began a descent to keep him in sight and get below his altitude. As I was descending; we got an RA. I also maneuvered behind the other aircraft's flight path to ensure further separation. We passed 1000 ft below and well behind the other aircraft. We were cleared back on course and resumed our climb. At no time did the controller issue avoidance instruction other than to allow us to maneuver behind the other aircraft. If we would have known that our flight paths were converging and not parallel; we would have delayed the climb. There is no blame to place here. The controller did tell us to maintain visual separation. I'm glad that he saw the potential conflict in time and were able to resolve it without incident.
Original NASA ASRS Text
Title: B737 FLT CREW IS ISSUED CLRNC TO MAINTAIN VISUAL ON TFC CLBING ON PARALLEL COURSE. TFC IS ACTUALLY CONVERGING AND B737 FLT CREW ALLOWS CONFLICT TO DEVELOP CAUSING TCAS RA.
Narrative: WE WERE BEING STEP CLBED BY DEP DUE TO TFC ABOVE US ALSO DEPARTING TO THE S. WHILE WE WERE LEVEL AT 11000 FT MSL; THE CONFLICTING TFC WAS POINTED OUT TO US AT 16000 FT MSL; 2 O'CLOCK POS AND ABOUT 10 MI. WE SAW THE TFC AND RPTED IT IN SIGHT. DEP THEN INSTRUCTED US TO MAINTAIN VISUAL AND CLB TO FL230. DEP ALSO TOLD US THE TFC WOULD BE TURNING TO A PARALLEL COURSE. THE FO (PF) CONTINUED THE CLB. AS I WATCHED THE TFC I NOTICED IT WAS NOT MOVING IN THE WINDSCREEN (IE; WOULD BE A CONFLICT IF SOMETHING DIDN'T CHANGE). DEP THEN INFORMED US THE TFC WOULD CROSS R TO L AHEAD OF US. AS THE TFC WAS STILL NOT MOVING IN THE WINDSCREEN; I TOLD THE PF TO SLOW THE CLB. THE PF DID NOT SLOW THE CLB AS HE WAS PLANNING TO CLB ABOVE THE TFC. I REMINDED HIM THAT WE WERE TO MAINTAIN A VISUAL AND THAT WE WOULD LOSE THE OTHER ACFT UNDER THE NOSE IF WE CONTINUED THE CLB. THE PF THEN REVERSED HIS CLB AND WE BEGAN TO TURN BEHIND THE TFC WITH ATC'S CONCURRENCE. AS THE PF ARRESTED HIS CLB AND BEGAN TO DSND AND TURN BEHIND AND BELOW THE TFC; WE GOT A CLB RA. OUR ACFT VECTOR WAS ALREADY BEHIND AND BELOW THE TFC AND TO COMPLY WITH THE TA/RA CLB COMMAND WOULD HAVE BEEN THE WRONG ACTION. AS THE TCAS CAUGHT UP WITH OUR ACFT VECTOR; IT DIRECTED A DSCNT WHICH WE WERE ALREADY IN. WE PASSED BEHIND AND BELOW THE ACFT WITH 1000 FT ALT SEPARATION. THE REMAINDER OF THE FLT WAS UNEVENTFUL. I COULD HAVE BEEN MORE ASSERTIVE IN MY DIRECTIVE COMMENTS TO THE PF. DEP SHOULD HAVE ENSURED THAT OUR COURSE WOULD IN FACT PARALLEL THE OTHER ACFT'S COURSE. SUPPLEMENTAL INFO FROM ACN 764272: WHILE CLBING OUT ON THE DEP WE WERE GIVEN TFC AT OUR 2 O'CLOCK POS AND WERE TOLD THAT HE WAS PARALLELING OUR COURSE. WE CALLED HIM IN SIGHT. WE WERE GIVEN INSTRUCTIONS TO MAINTAIN VISUAL CONTACT AND CLB FROM 11000 FT TO FL230. THE FO (ME) WAS FLYING AT THE TIME. WE WERE LIGHT (32 PAX) AND I BEGAN THE CLB. IN THE CLB; THE CAPT NOTICED THAT THE OTHER ACFT WAS STATIONARY IN THE WINDSCREEN (CONVERGING COURSE) AND DIRECTED THAT I LEVELOFF. AT THE SAME TIME; THE CTLR STATED THAT THE TFC WOULD NOW BE MOVING FROM R TO L. AT THAT POINT I BEGAN A DSCNT TO KEEP HIM IN SIGHT AND GET BELOW HIS ALT. AS I WAS DSNDING; WE GOT AN RA. I ALSO MANEUVERED BEHIND THE OTHER ACFT'S FLT PATH TO ENSURE FURTHER SEPARATION. WE PASSED 1000 FT BELOW AND WELL BEHIND THE OTHER ACFT. WE WERE CLRED BACK ON COURSE AND RESUMED OUR CLB. AT NO TIME DID THE CTLR ISSUE AVOIDANCE INSTRUCTION OTHER THAN TO ALLOW US TO MANEUVER BEHIND THE OTHER ACFT. IF WE WOULD HAVE KNOWN THAT OUR FLT PATHS WERE CONVERGING AND NOT PARALLEL; WE WOULD HAVE DELAYED THE CLB. THERE IS NO BLAME TO PLACE HERE. THE CTLR DID TELL US TO MAINTAIN VISUAL SEPARATION. I'M GLAD THAT HE SAW THE POTENTIAL CONFLICT IN TIME AND WERE ABLE TO RESOLVE IT WITHOUT INCIDENT.
Data retrieved from NASA's ASRS site as of January 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.