Regional Jet 700 ER/LR (CRJ700)
Flight Crew Air Transport Pilot (ATP)
Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Took Evasive Action
Procedure; Environment - Non Weather Related
This report is for informational purposes as ORD TRACON said they had had several such wake occurrences lately and were tracking them.Inbound to ORD we encountered fairly severe wake turbulence while descending on the WYNDE6 arrival in TRACON airspace.We were cleared by ORD center to 10;000 MSL and had completed our descent checklist so the passengers were seated with seat belts fastened.We were out of 11;000 MSL and about 9 miles in trail of a heavy who was assigned to a different runway and level at 11;000 MSL.We had just crossed the eastern shore of Lake Michigan when our aircraft started to shake and buffet side to side. We were approximately at 10;700 MSL when this began. We advised ATC that we were encountering a wake and they cleared us to descend to 7000. As our descent continued the wake became more violent and I had to use fairly aggressive control inputs to stop large rolling movements both left and right so it was obvious that we descending deeper into it. I deemed it safer to climb and I advised ATC that I was climbing out of it and would return to 11;000 MSL.The autopilot was disconnected and we also flew north of course to exit up and out. The buffeting stopped as we climbed through about 10;700 MSL.We took a moment to contact the cabin crew to see if there were any injuries. Fortunately everyone was seated and both flight attendants were OK.We then were cleared by ATC direct to an intersection that took us well away from the heavy's track and were cleared to 7000. The rest of the flight was uneventful.After landing in ORD; ATC had us call TRACON to discuss the incident. They said they had had several such occurrences recently and would file a report.Inadequate separation given winds aloft and atmospherics.Greater than 1000 FT separation in altitude and more distance behind a heavy recommended.
CRJ-700 Captain reported encountering 'fairly severe' wake turbulence nine miles in trail of a heavy jet on the WYNDE6 arrival into ORD.