MD80 crew had encounter with wake turbulence departing runway 22L at ord.

Attributes
ACN	457166
Time
Date	199912
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 600
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Flight Phase	climbout : initial
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	457166
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	inflight encounter : wake turbulence other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : regained aircraft control none taken : insufficient time
Supplementary
Problem Areas	Weather ATC Human Performance FAA
Primary Problem	FAA
Situations
ATC Facility	procedure or policy : ord.tower

Narrative:

Wake turbulence encounter. We were cleared for takeoff with a turn to 140 degree heading while preceding B737 departure was still on runway. The B737 lifted off before we released the brakes. The left turn to 140 degrees at 400 ft took us through the wake turbulence of the B737 resulting in a very rapid roll of 20-25 degrees to the left. This was counteracted with no further problems but it was very disconcerting considering the relatively low altitude of approximately 600 ft AGL. I regret not informing the tower of this encounter. Although I did inform the dfw tower of a wake encounter under almost exactly the same circumstances on a previous occasion. After 2 of these encounters at low altitude, I don't consider it safe to take off immediately after a preceding jet, even one of similar type to cause a large uncommanded roll when in close proximity. I think that this issue should be raised with the controllers as a safety matter. In the future, I will not accept any clearance to take off while the preceding plane is still rolling. It may be a legal clearance but it's not smart.

Original NASA ASRS Text

Title: MD80 CREW HAD ENCOUNTER WITH WAKE TURB DEPARTING RWY 22L AT ORD.

Narrative: WAKE TURB ENCOUNTER. WE WERE CLRED FOR TKOF WITH A TURN TO 140 DEG HDG WHILE PRECEDING B737 DEP WAS STILL ON RWY. THE B737 LIFTED OFF BEFORE WE RELEASED THE BRAKES. THE L TURN TO 140 DEGS AT 400 FT TOOK US THROUGH THE WAKE TURB OF THE B737 RESULTING IN A VERY RAPID ROLL OF 20-25 DEGS TO THE L. THIS WAS COUNTERACTED WITH NO FURTHER PROBS BUT IT WAS VERY DISCONCERTING CONSIDERING THE RELATIVELY LOW ALT OF APPROX 600 FT AGL. I REGRET NOT INFORMING THE TWR OF THIS ENCOUNTER. ALTHOUGH I DID INFORM THE DFW TWR OF A WAKE ENCOUNTER UNDER ALMOST EXACTLY THE SAME CIRCUMSTANCES ON A PREVIOUS OCCASION. AFTER 2 OF THESE ENCOUNTERS AT LOW ALT, I DON'T CONSIDER IT SAFE TO TAKE OFF IMMEDIATELY AFTER A PRECEDING JET, EVEN ONE OF SIMILAR TYPE TO CAUSE A LARGE UNCOMMANDED ROLL WHEN IN CLOSE PROX. I THINK THAT THIS ISSUE SHOULD BE RAISED WITH THE CTLRS AS A SAFETY MATTER. IN THE FUTURE, I WILL NOT ACCEPT ANY CLRNC TO TAKE OFF WHILE THE PRECEDING PLANE IS STILL ROLLING. IT MAY BE A LEGAL CLRNC BUT IT'S NOT SMART.

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.