Less than standard separation when reporter turned a commuter BE02 inside and across the departure t...

Attributes
ACN	337333
Time
Date	199605
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : lnk
State Reference	NE
Altitude	msl bound lower : 3400 msl bound upper : 3400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : lnk tower : lnk
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : local
Qualification	controller : radar
Experience	controller radar : 10
ASRS Report	337333
Person 2
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Events
Anomaly	non adherence : required legal separation non adherence : published procedure non adherence : clearance
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 15000 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

The cessna had departed the lnk airport on a 140 degree heading and the beech had been cleared for takeoff on the parallel runway with a heading of 170 degrees assigned. During my position relief briefing which happened after the above, I was advised that the cessna may be turned back into my departure corridor. I took the position and it appeared to me that the cessna was drifting back toward the west. The beech had not started departure roll yet, so I called the east departure controller and asked for a 90 degree heading on the beech so as to pass north of the cessna. It was approved by the east controller. By this time the beech had started his takeoff roll, so I waited until he was airborne and gave him the new heading and asked him to start the turn as soon as feasible and issued traffic on the cessna at his 10 O'clock and 3 mi. I continued to watch the situation and observed the rate of turn was not to my liking and turned the beech to 60 degrees to increase his rate of turn to obtain the divergence I needed. I believe I had the proper divergence, but the conflict alert went off. My perception that the cessna was drifting back into the departure path of the beech, and having worked with this particular commuter for the past 8 yrs I believed that they would start their turn to the east immediately off the runway as they always have, led me into a situation I had to watch more closely than should have been necessary. In the future I will definitely use a different action to facilitate the separation of aircraft. In hindsight a turn to the southwest for the beech would have been a better idea. I believe my intent to get the beech commuter on course as soon as possible added to my original decision to turn the beech to the east instead of to the west. I would like to add, that as usual the conflict alert did not go off until after the aircraft had passed.

Original NASA ASRS Text

Title: LTSS WHEN RPTR TURNED A COMMUTER BE02 INSIDE AND ACROSS THE DEP TRACK OF A C172. CONFLICT ALERT ACTIVATED AFTER THE ACFT HAD PASSED. THE BE02 REMAINED ON THE RPTR'S FREQ DURING THIS MANEUVER. OPERROR.

Narrative: THE CESSNA HAD DEPARTED THE LNK ARPT ON A 140 DEG HDG AND THE BEECH HAD BEEN CLRED FOR TKOF ON THE PARALLEL RWY WITH A HDG OF 170 DEGS ASSIGNED. DURING MY POS RELIEF BRIEFING WHICH HAPPENED AFTER THE ABOVE, I WAS ADVISED THAT THE CESSNA MAY BE TURNED BACK INTO MY DEP CORRIDOR. I TOOK THE POS AND IT APPEARED TO ME THAT THE CESSNA WAS DRIFTING BACK TOWARD THE W. THE BEECH HAD NOT STARTED DEP ROLL YET, SO I CALLED THE E DEP CTLR AND ASKED FOR A 90 DEG HDG ON THE BEECH SO AS TO PASS N OF THE CESSNA. IT WAS APPROVED BY THE E CTLR. BY THIS TIME THE BEECH HAD STARTED HIS TKOF ROLL, SO I WAITED UNTIL HE WAS AIRBORNE AND GAVE HIM THE NEW HDG AND ASKED HIM TO START THE TURN AS SOON AS FEASIBLE AND ISSUED TFC ON THE CESSNA AT HIS 10 O'CLOCK AND 3 MI. I CONTINUED TO WATCH THE SIT AND OBSERVED THE RATE OF TURN WAS NOT TO MY LIKING AND TURNED THE BEECH TO 60 DEGS TO INCREASE HIS RATE OF TURN TO OBTAIN THE DIVERGENCE I NEEDED. I BELIEVE I HAD THE PROPER DIVERGENCE, BUT THE CONFLICT ALERT WENT OFF. MY PERCEPTION THAT THE CESSNA WAS DRIFTING BACK INTO THE DEP PATH OF THE BEECH, AND HAVING WORKED WITH THIS PARTICULAR COMMUTER FOR THE PAST 8 YRS I BELIEVED THAT THEY WOULD START THEIR TURN TO THE E IMMEDIATELY OFF THE RWY AS THEY ALWAYS HAVE, LED ME INTO A SIT I HAD TO WATCH MORE CLOSELY THAN SHOULD HAVE BEEN NECESSARY. IN THE FUTURE I WILL DEFINITELY USE A DIFFERENT ACTION TO FACILITATE THE SEPARATION OF ACFT. IN HINDSIGHT A TURN TO THE SW FOR THE BEECH WOULD HAVE BEEN A BETTER IDEA. I BELIEVE MY INTENT TO GET THE BEECH COMMUTER ON COURSE AS SOON AS POSSIBLE ADDED TO MY ORIGINAL DECISION TO TURN THE BEECH TO THE E INSTEAD OF TO THE W. I WOULD LIKE TO ADD, THAT AS USUAL THE CONFLICT ALERT DID NOT GO OFF UNTIL AFTER THE ACFT HAD PASSED.

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.

Less than standard separation when reporter turned a commuter BE02 inside and across the departure track of a C172. Conflict alert activated after the aircraft had passed. The BE02 remained on the reporter's frequency during this maneuver. Operational error.