Narrative:

Level at FL390, given heading change for traffic opposite direction miles ahead (15 degrees to the right). I read back 15 degrees to the right and looked down for a min to finish programming FMS flight plan. When I looked back up we were level, didn't notice captain had turned opposite to instructions. Since heading change wasn't big, didn't notice bank opposite. Then ATC asked what our heading was and when I crosschecked my bug with what we were on, saw mistake and told ATC we messed up. We got a descent clearance to make his planning (ATC) work out and were told to do a good rate down. (No visual or TCASII TA's.) captain didn't know why he turned the other way, just a brain block. I fly with this person all the time and he's a very experienced senior captain. Just didn't catch the turn. We should probably not look at FMS until correct turnsecond officerther changes are complete. There is a lot of button pushing and staying ahead of electronics in these modern jets. In addition, controller initial instructions were given as 'let's see, 15 degrees to the right' which captain thought he said 15 degrees left, even as I read back 15 degrees to the right. It was a little casual in the wording for an ATC instructions.

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Original NASA ASRS Text

Title: CL600 CREW TURNS THE WRONG WAY WHEN THEY RECEIVE A NON STANDARD TERMINOLOGY HDG CHANGE AND BECOME DISTR WITH FMS.

Narrative: LEVEL AT FL390, GIVEN HDG CHANGE FOR TFC OPPOSITE DIRECTION MILES AHEAD (15 DEGS TO THE R). I READ BACK 15 DEGS TO THE R AND LOOKED DOWN FOR A MIN TO FINISH PROGRAMMING FMS FLT PLAN. WHEN I LOOKED BACK UP WE WERE LEVEL, DIDN'T NOTICE CAPT HAD TURNED OPPOSITE TO INSTRUCTIONS. SINCE HDG CHANGE WASN'T BIG, DIDN'T NOTICE BANK OPPOSITE. THEN ATC ASKED WHAT OUR HDG WAS AND WHEN I XCHKED MY BUG WITH WHAT WE WERE ON, SAW MISTAKE AND TOLD ATC WE MESSED UP. WE GOT A DSCNT CLRNC TO MAKE HIS PLANNING (ATC) WORK OUT AND WERE TOLD TO DO A GOOD RATE DOWN. (NO VISUAL OR TCASII TA'S.) CAPT DIDN'T KNOW WHY HE TURNED THE OTHER WAY, JUST A BRAIN BLOCK. I FLY WITH THIS PERSON ALL THE TIME AND HE'S A VERY EXPERIENCED SENIOR CAPT. JUST DIDN'T CATCH THE TURN. WE SHOULD PROBABLY NOT LOOK AT FMS UNTIL CORRECT TURNS/OTHER CHANGES ARE COMPLETE. THERE IS A LOT OF BUTTON PUSHING AND STAYING AHEAD OF ELECTRONICS IN THESE MODERN JETS. IN ADDITION, CTLR INITIAL INSTRUCTIONS WERE GIVEN AS 'LET'S SEE, 15 DEGS TO THE R' WHICH CAPT THOUGHT HE SAID 15 DEGS L, EVEN AS I READ BACK 15 DEGS TO THE R. IT WAS A LITTLE CASUAL IN THE WORDING FOR AN ATC INSTRUCTIONS.

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.