Narrative:

Small transport X departed runway 25 at roc and was given runway heading for vectors by clearance delivery. I radar idented small transport X. I was on the landline for a few moments coordinating with the center for higher than the 10000' small transport X was assigned to top slow moving traffic on the same route at 10000'. Medium large transport Y departed runway 22 on runway heading and was radar idented. When the 30 degree divergence I had between small transport X and medium large transport Y appeared to decrease (15 degrees is minimum) I instructed small transport X to turn right heading 260 degrees. The pilot read back the heading then questioned it. At that time small transport X's radar target showed a well defined left turn, through the path of the climbing medium large transport Y. I instructed small transport X to fly heading 160 degrees and reminded him that he was assigned runway heading. Sep began to increase. The computer plot indicated that small transport X started a slow left turn the moment I said 'radar contact.' small transport X passed below and in front of medium large transport Y by 400' and 1/4 mi in IMC. The pilot also showed that if I had given small transport X a turn back to the west he would have had a second chance to tangle with the medium large transport Y in the clouds. The tapes revealed that small transport X was issued and read back, 'fly runway heading,' 3 times before he departed and commenced his unauthorized turn on course. From now on, if my sep is based on the divergence of successive departures I will re-emphasize, 'fly runway heading.' I'm beginning to feel like a babysitter. Note: this incident is being processed by FAA flight standards as a pilot deviation.

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Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN SMT AND MLG AS A RESULT OF PLT DEVIATION.

Narrative: SMT X DEPARTED RWY 25 AT ROC AND WAS GIVEN RWY HDG FOR VECTORS BY CLRNC DELIVERY. I RADAR IDENTED SMT X. I WAS ON THE LANDLINE FOR A FEW MOMENTS COORDINATING WITH THE CENTER FOR HIGHER THAN THE 10000' SMT X WAS ASSIGNED TO TOP SLOW MOVING TFC ON THE SAME ROUTE AT 10000'. MLG Y DEPARTED RWY 22 ON RWY HDG AND WAS RADAR IDENTED. WHEN THE 30 DEG DIVERGENCE I HAD BTWN SMT X AND MLG Y APPEARED TO DECREASE (15 DEGS IS MINIMUM) I INSTRUCTED SMT X TO TURN RIGHT HDG 260 DEGS. THE PLT READ BACK THE HDG THEN QUESTIONED IT. AT THAT TIME SMT X'S RADAR TARGET SHOWED A WELL DEFINED LEFT TURN, THROUGH THE PATH OF THE CLBING MLG Y. I INSTRUCTED SMT X TO FLY HDG 160 DEGS AND REMINDED HIM THAT HE WAS ASSIGNED RWY HDG. SEP BEGAN TO INCREASE. THE COMPUTER PLOT INDICATED THAT SMT X STARTED A SLOW LEFT TURN THE MOMENT I SAID 'RADAR CONTACT.' SMT X PASSED BELOW AND IN FRONT OF MLG Y BY 400' AND 1/4 MI IN IMC. THE PLT ALSO SHOWED THAT IF I HAD GIVEN SMT X A TURN BACK TO THE W HE WOULD HAVE HAD A SECOND CHANCE TO TANGLE WITH THE MLG Y IN THE CLOUDS. THE TAPES REVEALED THAT SMT X WAS ISSUED AND READ BACK, 'FLY RWY HDG,' 3 TIMES BEFORE HE DEPARTED AND COMMENCED HIS UNAUTH TURN ON COURSE. FROM NOW ON, IF MY SEP IS BASED ON THE DIVERGENCE OF SUCCESSIVE DEPS I WILL RE-EMPHASIZE, 'FLY RWY HDG.' I'M BEGINNING TO FEEL LIKE A BABYSITTER. NOTE: THIS INCIDENT IS BEING PROCESSED BY FAA FLT STANDARDS AS A PLTDEV.

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.