Narrative:

OJT in progress. The developmental had received recommendation for certification on local control the previous day. Heavy air carrier X departed runway 9R heading 090. Air carrier Y, runway 9L, was issued takeoff clearance 1 min later. Runways 9L/9R are separated by more than 2500'. Prior to issuing the takeoff clearance to Y, I inquired as to the intentions of the developmental concerning separation. He stated he planned heading 075 for Y after departure. Y was initially given runway heading and cleared for takeoff with X 1 1/2 mi away. Once Y became airborne, I visually observed the climb rate to be greater than that of X and instructed the developmental to turn Y right to heading 120 to pass above the flight path of the heavy jet and to retain Y on the frequency and apply visual separation. With both aircraft routed to the north departure controller, this would be more expeditious and provide a better flow. Once Y crossed over the flight path of X, air carrier Y was turned left to parallel and visual separation was maintained by local control until the departure controller turned X left to heading 350. Y was above the heavy's flight path at all times. At no time were the flight paths ever projected to cross, thus the initial intention of 15 degree divergence. Once the aircraft performance was observed and visual separation ensured, Y was turned, and as the data extraction confirmed, passed approximately 170' above the flight path of the heavy jet at the point the courses intersected. When Y was turned to heading 090, on the south side of the heavy's course, and still above the flight path, the pilot questioned about the traffic and inquired of its altitude. He was told the traffic was being worked by departure and being vectored north and climbing. This is the situation in which visual separation was applied, that a supervisor in the radar room questioned. Upon reviewing tapes and interviewing the individuals concerned, the question of separation was resolved by verifying visual separation was indeed applied. However, in reviewing the tapes, the area manager discovered that Y had been issued takeoff clearance 1 min after X heavy. At this point, an operational error was ruled citing violation of 7110.65F para 3-108c(2) (2 min requirement when a parallel runway separated by more than 2500' or more when projected flight paths will cross). No evasive action was required or taken by anyone. Contributing factors, if any, would be traffic density (a 114 hour). Suggestions on preventing recurrence: 'clarify' para 3-108c(2). The para involves initial departure separation. The noted occurrence transpired when both aircraft involved were airborne. At what point is a departure considered en route? Initial departure instructions ensured that projected flight paths would not cross. It was when the aircraft involved were airborne, on departure climbout, and Y observed to be climbing faster, then turned and passed above the actual, physical, not projected, flight path.

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Original NASA ASRS Text

Title: VIOLATION OF WAKE TURBULENCE SEPARATION CRITERION. OPERATIONAL ERROR.

Narrative: OJT IN PROGRESS. THE DEVELOPMENTAL HAD RECEIVED RECOMMENDATION FOR CERTIFICATION ON LCL CTL THE PREVIOUS DAY. HVY ACR X DEPARTED RWY 9R HDG 090. ACR Y, RWY 9L, WAS ISSUED TKOF CLRNC 1 MIN LATER. RWYS 9L/9R ARE SEPARATED BY MORE THAN 2500'. PRIOR TO ISSUING THE TKOF CLRNC TO Y, I INQUIRED AS TO THE INTENTIONS OF THE DEVELOPMENTAL CONCERNING SEPARATION. HE STATED HE PLANNED HDG 075 FOR Y AFTER DEP. Y WAS INITIALLY GIVEN RWY HDG AND CLRED FOR TKOF WITH X 1 1/2 MI AWAY. ONCE Y BECAME AIRBORNE, I VISUALLY OBSERVED THE CLIMB RATE TO BE GREATER THAN THAT OF X AND INSTRUCTED THE DEVELOPMENTAL TO TURN Y RIGHT TO HDG 120 TO PASS ABOVE THE FLT PATH OF THE HVY JET AND TO RETAIN Y ON THE FREQ AND APPLY VISUAL SEPARATION. WITH BOTH ACFT ROUTED TO THE N DEP CTLR, THIS WOULD BE MORE EXPEDITIOUS AND PROVIDE A BETTER FLOW. ONCE Y CROSSED OVER THE FLT PATH OF X, ACR Y WAS TURNED LEFT TO PARALLEL AND VISUAL SEPARATION WAS MAINTAINED BY LCL CTL UNTIL THE DEP CTLR TURNED X LEFT TO HDG 350. Y WAS ABOVE THE HVY'S FLT PATH AT ALL TIMES. AT NO TIME WERE THE FLT PATHS EVER PROJECTED TO CROSS, THUS THE INITIAL INTENTION OF 15 DEG DIVERGENCE. ONCE THE ACFT PERFORMANCE WAS OBSERVED AND VISUAL SEPARATION ENSURED, Y WAS TURNED, AND AS THE DATA EXTRACTION CONFIRMED, PASSED APPROX 170' ABOVE THE FLT PATH OF THE HVY JET AT THE POINT THE COURSES INTERSECTED. WHEN Y WAS TURNED TO HDG 090, ON THE S SIDE OF THE HVY'S COURSE, AND STILL ABOVE THE FLT PATH, THE PLT QUESTIONED ABOUT THE TFC AND INQUIRED OF ITS ALT. HE WAS TOLD THE TFC WAS BEING WORKED BY DEP AND BEING VECTORED N AND CLIMBING. THIS IS THE SITUATION IN WHICH VISUAL SEPARATION WAS APPLIED, THAT A SUPVR IN THE RADAR ROOM QUESTIONED. UPON REVIEWING TAPES AND INTERVIEWING THE INDIVIDUALS CONCERNED, THE QUESTION OF SEPARATION WAS RESOLVED BY VERIFYING VISUAL SEPARATION WAS INDEED APPLIED. HOWEVER, IN REVIEWING THE TAPES, THE AREA MGR DISCOVERED THAT Y HAD BEEN ISSUED TKOF CLRNC 1 MIN AFTER X HVY. AT THIS POINT, AN OPERATIONAL ERROR WAS RULED CITING VIOLATION OF 7110.65F PARA 3-108C(2) (2 MIN REQUIREMENT WHEN A PARALLEL RWY SEPARATED BY MORE THAN 2500' OR MORE WHEN PROJECTED FLT PATHS WILL CROSS). NO EVASIVE ACTION WAS REQUIRED OR TAKEN BY ANYONE. CONTRIBUTING FACTORS, IF ANY, WOULD BE TFC DENSITY (A 114 HOUR). SUGGESTIONS ON PREVENTING RECURRENCE: 'CLARIFY' PARA 3-108C(2). THE PARA INVOLVES INITIAL DEP SEPARATION. THE NOTED OCCURRENCE TRANSPIRED WHEN BOTH ACFT INVOLVED WERE AIRBORNE. AT WHAT POINT IS A DEP CONSIDERED ENRTE? INITIAL DEP INSTRUCTIONS ENSURED THAT PROJECTED FLT PATHS WOULD NOT CROSS. IT WAS WHEN THE ACFT INVOLVED WERE AIRBORNE, ON DEP CLIMBOUT, AND Y OBSERVED TO BE CLIMBING FASTER, THEN TURNED AND PASSED ABOVE THE ACTUAL, PHYSICAL, NOT PROJECTED, FLT PATH.

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.