Narrative:

During cruise at FL350, en route ord-den, center gave us a heading to parallel traffic (Y) at same altitude, which we were overtaking. Captain was flying, but engrossed in conversation with an observer in the cockpit. Captain turned to the assigned heading as instructed by ATC. About 150 NM from ogh, captain changed heading about 10 degrees to the left (more toward obh, which was on our filed route). Shortly thereafter, center requested our heading and gave us a right turn. The aircraft Y, which we were on heading to parallel, was in sight about 5 mi off our left wing. I did not question the captain's heading change, as he had previously on this trip sequence shaved a few degrees off vector headings when it benefitted us; i.e., more direct. This time after responding to center's right turn instruction, captain indicated to first officer that he thought we were cleared direct obh. There was no real conflict but obviously a few anxious moments for the controller when he observed our heading change toward the other aircraft Y. Nothing new here, cockpit distraction, and a first officer new to the aircraft, and not bold enough to interrupt the captain's conversation to clarify the unwarranted heading change. In spite of all our cockpit management training, it still happens--we are inhibited by personalities. We situation there and say nothing when there's something amiss. No magical solution, we know the problem, just gotta keep working' at it.

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Original NASA ASRS Text

Title: ACR WDB BEING VECTORED PAST PARALLEL TRAFFIC DEVIATES FROM ASSIGNED HEADING.

Narrative: DURING CRUISE AT FL350, ENRTE ORD-DEN, CENTER GAVE US A HDG TO PARALLEL TFC (Y) AT SAME ALT, WHICH WE WERE OVERTAKING. CAPT WAS FLYING, BUT ENGROSSED IN CONVERSATION WITH AN OBSERVER IN THE COCKPIT. CAPT TURNED TO THE ASSIGNED HDG AS INSTRUCTED BY ATC. ABOUT 150 NM FROM OGH, CAPT CHANGED HDG ABOUT 10 DEGS TO THE LEFT (MORE TOWARD OBH, WHICH WAS ON OUR FILED ROUTE). SHORTLY THEREAFTER, CENTER REQUESTED OUR HDG AND GAVE US A RIGHT TURN. THE ACFT Y, WHICH WE WERE ON HDG TO PARALLEL, WAS IN SIGHT ABOUT 5 MI OFF OUR LEFT WING. I DID NOT QUESTION THE CAPT'S HDG CHANGE, AS HE HAD PREVIOUSLY ON THIS TRIP SEQUENCE SHAVED A FEW DEGS OFF VECTOR HDGS WHEN IT BENEFITTED US; I.E., MORE DIRECT. THIS TIME AFTER RESPONDING TO CENTER'S RIGHT TURN INSTRUCTION, CAPT INDICATED TO F/O THAT HE THOUGHT WE WERE CLRED DIRECT OBH. THERE WAS NO REAL CONFLICT BUT OBVIOUSLY A FEW ANXIOUS MOMENTS FOR THE CTLR WHEN HE OBSERVED OUR HDG CHANGE TOWARD THE OTHER ACFT Y. NOTHING NEW HERE, COCKPIT DISTR, AND A F/O NEW TO THE ACFT, AND NOT BOLD ENOUGH TO INTERRUPT THE CAPT'S CONVERSATION TO CLARIFY THE UNWARRANTED HDG CHANGE. IN SPITE OF ALL OUR COCKPIT MGMNT TRNING, IT STILL HAPPENS--WE ARE INHIBITED BY PERSONALITIES. WE SIT THERE AND SAY NOTHING WHEN THERE'S SOMETHING AMISS. NO MAGICAL SOLUTION, WE KNOW THE PROB, JUST GOTTA KEEP WORKING' AT IT.

Data retrieved from NASA's ASRS site as of August 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.