MD83 flight crew encounters wake turbulence during approach to ord.

Attributes
ACN	722221
Time
Date	200612
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl bound lower : 200 agl bound upper : 800
Environment
Flight Conditions	IMC
Weather Elements	Windshear
Aircraft 1
Controlling Facilities	tower : ord.tower tower : phx.tower
Operator	common carrier : air carrier
Make Model Name	MD-83
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer only : 9r
Flight Phase	landing : go around
Route In Use	approach : instrument precision
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	landing : roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 14000 flight time type : 1700
ASRS Report	722221
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : wake turbulence other anomaly
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : executed go around flight crew : exited adverse environment
Supplementary
Problem Areas	Environmental Factor
Primary Problem	Environmental Factor

Narrative:

Ord ILS runway 9R; 400 ft overcast; 3/4 mile visibility; RVR 5000 ft. ATC advised caution for wake turbulence for a B747 landing ahead of us. At 200 ft AGL aircraft encountered wake turbulence. Airplane rolled right; autoplt corrected with a left bank. Combination of left roll and wake turbulence took aircraft left of centerline. Captain simultaneously disconnected the autoplt; aligned the airplane with the runway; and initiated a go around. Uneventful ILS and landing on the next approach to the same runway.

Original NASA ASRS Text

Title: MD83 FLT CREW ENCOUNTERS WAKE TURB DURING APCH TO ORD.

Narrative: ORD ILS RWY 9R; 400 FT OVERCAST; 3/4 MILE VIS; RVR 5000 FT. ATC ADVISED CAUTION FOR WAKE TURB FOR A B747 LNDG AHEAD OF US. AT 200 FT AGL ACFT ENCOUNTERED WAKE TURB. AIRPLANE ROLLED R; AUTOPLT CORRECTED WITH A L BANK. COMBINATION OF L ROLL AND WAKE TURB TOOK ACFT L OF CTRLINE. CAPT SIMULTANEOUSLY DISCONNECTED THE AUTOPLT; ALIGNED THE AIRPLANE WITH THE RWY; AND INITIATED A GAR. UNEVENTFUL ILS AND LNDG ON THE NEXT APCH TO THE SAME RWY.

Data retrieved from NASA's ASRS site as of January 2009 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.