Narrative:

I was giving dual instruction to a student pilot in his first experience in a controled field. We obtained a VFR departure clearance to fly heading 250 degrees and climb to 4500 ft. The winds were gusty and the student was having difficulty holding heading. In addition, the bumps made the wet compass act erratically. Tower instructed us to fly initial heading 230 degrees and contact departure. Departure control replied, 'climb to requested altitude,' which I interpreted to mean on course as well. After about 5 mins, the controller asked our heading, which was 235 degrees at that time, which I told ATC. The student was having trouble arresting the left turning tendency, and even though he was attempting to fly our clearance heading of 250 degrees, we were indicating 235 degrees. About a min or so later, the controller called again asking our heading, which was still 235 degrees. He indicated our ground track was 250 degrees, which did not surprise me with the strong winds, but he never told us to turn or fly a new heading, he just seemed to take issue with our indicated heading. While I continued to provide him with the information he requested, I looked down and saw the C130 passing quickly underneath and to the right of our plane. ATC then advised me of the C130 and told me he was 'climbing through your altitude.' I responded we had the traffic and that it was no longer a factor. Had I known he was coming, I would have made sure we were well out of his way. I was unclr as to which heading to fly based on the given clearance of 250 degrees and lack of any assigned heading by departure control. I believe communications could have been better by ATC and myself.

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Original NASA ASRS Text

Title: A DEPARTING C172 AT 3000 FT HAS AN NMAC WITH A CLBING C130 JUST SW OF TYS, TN.

Narrative: I WAS GIVING DUAL INSTRUCTION TO A STUDENT PLT IN HIS FIRST EXPERIENCE IN A CTLED FIELD. WE OBTAINED A VFR DEP CLRNC TO FLY HDG 250 DEGS AND CLB TO 4500 FT. THE WINDS WERE GUSTY AND THE STUDENT WAS HAVING DIFFICULTY HOLDING HDG. IN ADDITION, THE BUMPS MADE THE WET COMPASS ACT ERRATICALLY. TWR INSTRUCTED US TO FLY INITIAL HDG 230 DEGS AND CONTACT DEP. DEP CTL REPLIED, 'CLB TO REQUESTED ALT,' WHICH I INTERPED TO MEAN ON COURSE AS WELL. AFTER ABOUT 5 MINS, THE CTLR ASKED OUR HDG, WHICH WAS 235 DEGS AT THAT TIME, WHICH I TOLD ATC. THE STUDENT WAS HAVING TROUBLE ARRESTING THE L TURNING TENDENCY, AND EVEN THOUGH HE WAS ATTEMPTING TO FLY OUR CLRNC HDG OF 250 DEGS, WE WERE INDICATING 235 DEGS. ABOUT A MIN OR SO LATER, THE CTLR CALLED AGAIN ASKING OUR HDG, WHICH WAS STILL 235 DEGS. HE INDICATED OUR GND TRACK WAS 250 DEGS, WHICH DID NOT SURPRISE ME WITH THE STRONG WINDS, BUT HE NEVER TOLD US TO TURN OR FLY A NEW HDG, HE JUST SEEMED TO TAKE ISSUE WITH OUR INDICATED HDG. WHILE I CONTINUED TO PROVIDE HIM WITH THE INFO HE REQUESTED, I LOOKED DOWN AND SAW THE C130 PASSING QUICKLY UNDERNEATH AND TO THE R OF OUR PLANE. ATC THEN ADVISED ME OF THE C130 AND TOLD ME HE WAS 'CLBING THROUGH YOUR ALT.' I RESPONDED WE HAD THE TFC AND THAT IT WAS NO LONGER A FACTOR. HAD I KNOWN HE WAS COMING, I WOULD HAVE MADE SURE WE WERE WELL OUT OF HIS WAY. I WAS UNCLR AS TO WHICH HDG TO FLY BASED ON THE GIVEN CLRNC OF 250 DEGS AND LACK OF ANY ASSIGNED HDG BY DEP CTL. I BELIEVE COMS COULD HAVE BEEN BETTER BY ATC AND MYSELF.

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.