King air 350 captain reported encountering wake turbulence on arrival into ord.

Attributes
ACN	1567231
Time
Date	201808
Local Time Of Day	0601-1200
Place
Locale Reference	C90.TRACON
State Reference	IL
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Super King Air 350
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	STAR ERNNY 4
Flight Plan	IFR
Aircraft 2
Make Model Name	Medium Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 35 Flight Crew Total 14200 Flight Crew Type 225
Events
Anomaly	Inflight Event / Encounter Wake Vortex Encounter

Narrative:

While on the ernny 4 arrival we encountered wake turbulence at approximately 8000 feet in between clouds and in clear air. The aircraft pitched up and rolled to the left causing the autopilot to disengage. After the initial pitch and roll changes the aircraft encountered violent turbulence tossing cabin items and people; crew and passengers were all seat belted and no injuries. The first officer reported the wake turbulence to approach control and then we were advised that we were 5 miles in-trail of [another aircraft] at the same altitude. He asked if there were any injuries and we reported no. I believe we encountered the wake of the [other aircraft] because he descended from a higher altitude to our altitude in front of us. Traffic was heavy and we were instructed to maintain 240 knots or greater when we encountered the wake turbulence. After reporting the event we were slowed down and vectored onto 9L ILS approach behind the same traffic; and we maintained a dot high on the glide slope to make sure we did not encounter wake turbulence again. I am not positive that the wake we encountered came from the traffic ahead or other traffic that may have crossed our path. After many years of flying heavy jets this was a real eye opener for me; encountering wake turbulence like this at low altitude would be a real challenge.

Original NASA ASRS Text

Title: King Air 350 Captain reported encountering wake turbulence on arrival into ORD.

Narrative: While on the ERNNY 4 arrival we encountered wake turbulence at approximately 8000 feet in between clouds and in clear air. The aircraft pitched up and rolled to the left causing the autopilot to disengage. After the initial pitch and roll changes the aircraft encountered violent turbulence tossing cabin items and people; crew and passengers were all seat belted and no injuries. The First Officer reported the wake turbulence to Approach Control and then we were advised that we were 5 miles in-trail of [another aircraft] at the same altitude. He asked if there were any injuries and we reported no. I believe we encountered the wake of the [other aircraft] because he descended from a higher altitude to our altitude in front of us. Traffic was heavy and we were instructed to maintain 240 knots or greater when we encountered the wake turbulence. After reporting the event we were slowed down and vectored onto 9L ILS approach behind the same traffic; and we maintained a dot high on the glide slope to make sure we did not encounter wake turbulence again. I am not positive that the wake we encountered came from the traffic ahead or other traffic that may have crossed our path. After many years of flying heavy jets this was a real eye opener for me; encountering wake turbulence like this at low altitude would be a real challenge.

Data retrieved from NASA's ASRS site 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.