Den controller described a loss of heavy jet separation when launching air carriers off the parallel...

Narrative:

I departed the B757 off of runway 17L on a 080 heading. I then launched the B737 off runway 17R on a runway heading. I looked out the window and saw that the B757 was turning eastbound. I then told the B737 to turn left heading 095. The B757 was slower than normal to their turn and the B737 was faster in their turn. The B737 had the B757 in sight and inquired about them. I told the B737 what the B757 was doing. It looked closer than what it should have been. I needed to let the B737 go a little bit further on the runway heading before turning them southeast.

Original NASA ASRS Text

Title: DEN Controller described a loss of heavy jet separation when launching air carriers off the parallel Runway 17's; the first a heavy; slow to turn east; the second turning rapidly eastbound eroding the separation.

Narrative: I departed the B757 off of Runway 17L on a 080 heading. I then launched the B737 off Runway 17R on a runway heading. I looked out the window and saw that the B757 was turning eastbound. I then told the B737 to turn left heading 095. The B757 was slower than normal to their turn and the B737 was faster in their turn. The B737 had the B757 in sight and inquired about them. I told the B737 what the B757 was doing. It looked closer than what it should have been. I needed to let the B737 go a little bit further on the runway heading before turning them southeast.

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	967647
Time
Date	201108
Local Time Of Day	1201-1800
Place
Locale Reference	DEN.Tower
State Reference	CO
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	Vectors
Flight Plan	IFR
Person 1
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Deviation - Procedural Published Material / Policy

Den controller described a loss of heavy jet separation when launching air carriers off the parallel runway 17's; the first a heavy; slow to turn east; the second turning rapidly eastbound eroding the separation.