A TRACON departure controller was preoccupied with vectoring a departing B737 around WX and neglected to provide adequate separation with an arriving DH6.

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Attributes
ACN	409116
Time
Date	199807
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : las
State Reference	NV
Altitude	msl bound lower : 5200 msl bound upper : 5200
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : las
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air taxi
Make Model Name	Twin Otter DHC-6
Operating Under FAR Part	Part 135
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller military : 4 controller non radar : 2 controller radar : 8
ASRS Report	409116
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe inflight encounter : weather non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 4500 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

A B737 aircraft departed las vegas opposite direction runway 7, and had not 'tagged' on the radar display due to wrong transponder code being set. Lots of thunderstorm activity in the area. Controller turned the B737 aircraft to the northeast in order to avoid a WX cell that was directly in the path of the departure. The controller then coordinated with an adjoining in-house sector regarding the B737 flying through the airspace. At this point in time, the controller noticed a twin otter aircraft approximately 5 NM northeast of the B737 at 5000 ft. An immediate turn to the east was issued to the B737, and traffic information was exchanged. The B737 aircraft responded to an RA advising to climb. The twin otter had the B737 in sight and on TCASII, but separation minima had been lost. Contributing factors were WX, poor scanning technique, supervisor's inability to ensure a timely opposite direction departure, and controller working while having the flu.

Original NASA ASRS Text

Title: A TRACON DEP CTLR WAS PREOCCUPIED WITH VECTORING A DEPARTING B737 AROUND WX AND NEGLECTED TO PROVIDE ADEQUATE SEPARATION WITH AN ARRIVING DH6.

Narrative: A B737 ACFT DEPARTED LAS VEGAS OPPOSITE DIRECTION RWY 7, AND HAD NOT 'TAGGED' ON THE RADAR DISPLAY DUE TO WRONG XPONDER CODE BEING SET. LOTS OF TSTM ACTIVITY IN THE AREA. CTLR TURNED THE B737 ACFT TO THE NE IN ORDER TO AVOID A WX CELL THAT WAS DIRECTLY IN THE PATH OF THE DEP. THE CTLR THEN COORDINATED WITH AN ADJOINING IN-HOUSE SECTOR REGARDING THE B737 FLYING THROUGH THE AIRSPACE. AT THIS POINT IN TIME, THE CTLR NOTICED A TWIN OTTER ACFT APPROX 5 NM NE OF THE B737 AT 5000 FT. AN IMMEDIATE TURN TO THE E WAS ISSUED TO THE B737, AND TFC INFO WAS EXCHANGED. THE B737 ACFT RESPONDED TO AN RA ADVISING TO CLB. THE TWIN OTTER HAD THE B737 IN SIGHT AND ON TCASII, BUT SEPARATION MINIMA HAD BEEN LOST. CONTRIBUTING FACTORS WERE WX, POOR SCANNING TECHNIQUE, SUPVR'S INABILITY TO ENSURE A TIMELY OPPOSITE DIRECTION DEP, AND CTLR WORKING WHILE HAVING THE FLU.

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.