Pwk controller described a probable loss of separation event during an opposite direction operation;...

Narrative:

Runway configuration was landing runway 16 and departing runway 34. The weather was overcast 400 ft and the visibility was 1 3/4 mile. I was going on local control. We called north satellite for the release and they gave it to us when a astr was on a 9 mile final to runway 16 and a H25B was cleared for take off on a right turn to 040; he was told to no delay to ensure separation with the opposite direction jet. When he rotated and was airborne; I told him to turn as soon as he could and report established on the 040 heading; to ensure degrees divergence. The collision alarm never sounded. I was unable to tell if separation was lost. I estimate that separation was 2.5 miles or greater. By the time the H25B reported established on the 040 heading it was to close to tell at that time. I don't think separation was lost. Landing 16 and departing 34 is a normal configuration at pwk during bad weather conditions. The weather was below circle to 34 minimums; the only way with ceiling 400 ft overcast and 1 3/4 mile visibility is to land 16 and depart 34 which is a normal practice at pwk. Recommendation; next time I will just wait for traffic to land on runway 16 before launching someone off runway 34 opposite direction; even though it could cause a delay.

Original NASA ASRS Text

Title: PWK Controller described a probable loss of separation event during an opposite direction operation; noting waiting until traffic landed would have been a better decision.

Narrative: Runway configuration was landing Runway 16 and departing Runway 34. The weather was Overcast 400 FT and the visibility was 1 3/4 mile. I was going on Local Control. We called North Satellite for the release and they gave it to us when a ASTR was on a 9 mile final to Runway 16 and a H25B was cleared for take off on a right turn to 040; he was told to no delay to ensure separation with the opposite direction jet. When he rotated and was airborne; I told him to turn as soon as he could and report established on the 040 heading; to ensure degrees divergence. The Collision Alarm never sounded. I was unable to tell if separation was lost. I estimate that separation was 2.5 miles or greater. By the time the H25B reported established on the 040 heading it was to close to tell at that time. I don't think separation was lost. Landing 16 and departing 34 is a normal configuration at PWK during bad weather conditions. The weather was below circle to 34 minimums; the only way with ceiling 400 FT overcast and 1 3/4 mile visibility is to land 16 and depart 34 which is a normal practice at PWK. Recommendation; next time I will just wait for traffic to land on Runway 16 before launching someone off Runway 34 opposite direction; even though it could cause a delay.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	942413
Time
Date	201104
Local Time Of Day	1801-2400
Place
Locale Reference	PWK.Airport
State Reference	IL
Aircraft 1
Make Model Name	HS 125 Series
Flight Phase	Initial Climb
Flight Plan	IFR
Aircraft 2
Make Model Name	Gulfstream G100/G150 (IAI 1125 Astra)
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Local
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict

Pwk controller described a probable loss of separation event during an opposite direction operation; noting waiting until traffic landed would have been a better decision.