Narrative:

Flying a B747-200 at FL370, from ZZZ to jfk. En route to air (bellaire) we were rerted and sent northward towards jhw (johnstown). ZOB instructed us to turn left for traffic, and we turned to 330 degrees. After a few moments, we were asked our present heading (we acknowledged the initial call to turn 30 degrees left) and told him. The controller then gave us a vector of 030 degrees, turning us right 60 degrees for traffic avoidance. My crew and I were surprised by the widely varying vectors received in such a short time span, perhaps 30 seconds elapsed between vectors. We had no TCASII indications and 1 crew member had a visual on traffic that was not a factor. There may have been some confusion on the controller's part and/or our part in the instructions and readback of headings that can sound similar. 'Turn 30 left,' or turn '030' can sound the same, but if you are heading 360 degrees, it's markedly different. Similarly, '030' or '330' can sound similar when received or spoken. Recommend we consider using phraseology using twenty, thirty, forty, etc, such as vector 'three thirty degrees' or vector 'thirty degrees' to differentiate. An additional factor was that the crew was tired, having reported for duty at XB45, almost 13 hours earlier, with minimum actual rest the evening before, despite having an 8 hour rest period. This was the first leg of a pattern of flying, so getting up at XA15 required each of us to try and go to sleep much earlier in the evening than we were accustomed.

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Original NASA ASRS Text

Title: A B747-200 CREW QUESTIONED THE TERMINOLOGY THE CTLR USED FOR VECTOR HDGS TO AVOID A CONFLICT.

Narrative: FLYING A B747-200 AT FL370, FROM ZZZ TO JFK. ENRTE TO AIR (BELLAIRE) WE WERE RERTED AND SENT NORTHWARD TOWARDS JHW (JOHNSTOWN). ZOB INSTRUCTED US TO TURN L FOR TFC, AND WE TURNED TO 330 DEGS. AFTER A FEW MOMENTS, WE WERE ASKED OUR PRESENT HDG (WE ACKNOWLEDGED THE INITIAL CALL TO TURN 30 DEGS L) AND TOLD HIM. THE CTLR THEN GAVE US A VECTOR OF 030 DEGS, TURNING US R 60 DEGS FOR TFC AVOIDANCE. MY CREW AND I WERE SURPRISED BY THE WIDELY VARYING VECTORS RECEIVED IN SUCH A SHORT TIME SPAN, PERHAPS 30 SECONDS ELAPSED BTWN VECTORS. WE HAD NO TCASII INDICATIONS AND 1 CREW MEMBER HAD A VISUAL ON TFC THAT WAS NOT A FACTOR. THERE MAY HAVE BEEN SOME CONFUSION ON THE CTLR'S PART AND/OR OUR PART IN THE INSTRUCTIONS AND READBACK OF HDGS THAT CAN SOUND SIMILAR. 'TURN 30 L,' OR TURN '030' CAN SOUND THE SAME, BUT IF YOU ARE HDG 360 DEGS, IT'S MARKEDLY DIFFERENT. SIMILARLY, '030' OR '330' CAN SOUND SIMILAR WHEN RECEIVED OR SPOKEN. RECOMMEND WE CONSIDER USING PHRASEOLOGY USING TWENTY, THIRTY, FORTY, ETC, SUCH AS VECTOR 'THREE THIRTY DEGS' OR VECTOR 'THIRTY DEGS' TO DIFFERENTIATE. AN ADDITIONAL FACTOR WAS THAT THE CREW WAS TIRED, HAVING RPTED FOR DUTY AT XB45, ALMOST 13 HRS EARLIER, WITH MINIMUM ACTUAL REST THE EVENING BEFORE, DESPITE HAVING AN 8 HR REST PERIOD. THIS WAS THE FIRST LEG OF A PATTERN OF FLYING, SO GETTING UP AT XA15 REQUIRED EACH OF US TO TRY AND GO TO SLEEP MUCH EARLIER IN THE EVENING THAN WE WERE ACCUSTOMED.

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.