A CE750 First Officer and a ZFW Controller describe events surrounding a track deviation leading to a TCAS RA event. Both aircraft were at FL410.
Synopsis
A CE750 First Officer and a ZFW Controller describe events surrounding a track deviation leading to a TCAS RA event. Both aircraft were at FL410.
Narrative
[We were] en route to SGR at FL410 with the autopilot on over Lubbock; TX going direct to ABI. The Captain got up to use the restroom. ATC called with a reroute which I wrote down and proceeded to put in the FMS. The new route was to fly direct to ACT then CLL to the arrival. I typed ACT into the FMS and put it on top of ABI; pushed direct which brings up a message that asks if you want to change legs yes/no; I selected yes and then went back down to the FMS to type in CLL. When I looked up I noticed that we had turned quite a bit left which did not make sense so I starting looking on the MFD to see what the course looked like. About this time ATC said turn right to a heading of 140. I turned the heading knob to 140 and selected heading on the FGC. At about this same time I noticed a target on our TCAS that was red; an aural traffic call was heard; followed by climb; climb. I immediately clicked off the autopilot and initiated a climb to the right. About this time the Captain returned; reported to ATC that we were responding to a RA; he then took the aircraft controls to expedite the recovery to 41;000 FT. We climbed up to just over 42;000 FT. ATC gave us a phone number to call in regards to a possible pilot deviation.Discussing what happened and what could have been done differently: instead of going direct right away I could have selected heading mode then looked at the course before selecting direct to make sure it made sense. ATC could have given me a heading to intercept the new course. I am still not sure why the aircraft turned so far to the left; the new course was slightly left about 10-15 degrees. Lesson learned to not rush into changing course when there is a reroute and check; check; check. I am fairly new in this aircraft with this FMS and had just returned from 10 weeks off due to an injury. My inexperience was definitely a contributing factor.
Second reporter narrative
A CE510 was on frequency direct to Peach Springs (PGS); wrong-for-direction at FL410. URET showed him in conflict with a CE750 southeast-bound direct Abilene (ABI) direct and landing SGR. I asked the pilot of the CE510 if he would rather descend to FL400 or take a vector to miss traffic at FL410; he elected to take the turn. I issued him a turn of 15 degrees right.I knew that the CE750 would need an arrival routing into SGR; as it is in the Houston terminal area; so after she entered my sector I issued her a clearance; 'direct Waco; Alpha Charlie Tango; direct College Station; Charlie Lima Lima; and the BlueBell 2 arrival' (ACT..CLL.BLUBL2); which she read back. The turn from her original course; direct ABI to her new course; direct ACT should have been about 6 degrees left.Shortly thereafter; I observed the CE510 was well clear of the CE750's route; so I turned him 10 degrees back to the left. The pilot of the CE750 came back and verified that I wanted her to turn direct to Alpha Charlie Tango now; to which I replied 'affirmative'. About this time I re-cleared the CE510 direct to PGS. I observed the CE750 making a much more than 6 degree turn to the left toward the CE510 and issued her a clearance to fly a heading of 140 for traffic. After several seconds; when I did not observe a turn; I asked her heading and a male voice responded; 'Heading 080; responding to an RA; leveling back off;' to which I replied 'roger.' Once the CE750 was past the CE510; I re-cleared the pilot direct ACT and observed a turn from about 080 degrees toward ACT. I did not observe a turn between the time I issued the 140 heading and the time I re-cleared the pilot direct ACT.The pilot called the Operations Manager later and my understanding is that he said that the copilot entered the wrong command in the navigation system; which caused the autopilot to initiate the hard left turn. As for me; if I had taken the CE510 down to FL400; right-for-direction; this would not have happened. If I had waited until the CE750 was past the CE510 before issuing a clearance; odds are this would not have happened.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.