An air carrier ATR 42 got into wake turbulence behind a heavy.

Attributes
ACN	261859
Time
Date	199401
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	msl bound lower : 4500 msl bound upper : 4500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	ATR 42
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	approach : visual enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent other
Route In Use	approach : visual enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 1900 flight time type : 150
ASRS Report	261859
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter other non adherence : far other anomaly other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Air carrier flight mli-ord ATR 42 jan/thu/94 at XT00 local. While being vectored for a visual approach at ord we were following a heavy jet that descended in front and from above our altitude. Encountered severe wake turbulence causing roll of 45 degrees each side. Afterwards, controller stated we were 4 mi in trail.

Original NASA ASRS Text

Title: AN ACR ATR 42 GOT INTO WAKE TURB BEHIND A HVY.

Narrative: ACR FLT MLI-ORD ATR 42 JAN/THU/94 AT XT00 LCL. WHILE BEING VECTORED FOR A VISUAL APCH AT ORD WE WERE FOLLOWING A HVY JET THAT DSNDED IN FRONT AND FROM ABOVE OUR ALT. ENCOUNTERED SEVERE WAKE TURB CAUSING ROLL OF 45 DEGS EACH SIDE. AFTERWARDS, CTLR STATED WE WERE 4 MI IN TRAIL.

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.