EMB ERJ 145 ER/LR
Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Total 5830
Deviation - Altitude Excursion From Assigned Altitude; Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Environment - Non Weather Related; Procedure
On flight to ORD air traffic control advised First Officer and I of a heavy aircraft ahead and 1;000 ft above our assigned altitude. I reported aircraft in sight. As the other aircraft appeared closer and closer on TCAS I had the flight attendant sit down for possible wake turbulence. While on the MADII 4 Arrival somewhere after SOOLU ATC told us to descend [to] 7;000 ft. While slowing in order to descend we encountered a wake; losing about 100 ft than gaining 150 ft but no more than 200 feet. After the encounter I asked ATC for a heading to aid in reestablish on the arrival. He gave us a heading of 090 and we descended to 7;000 ft and complied with new assigned heading. At no point did the aircraft [TCAS] give any type of proximity caution / warning. Would like more distance between heavy aircraft.
On [our] flight to ORD; on the MADII 4 Arrival; between SOOLU and KURKK we were instructed to descend from 10;000 to 7;000. While we were slowing to descend our aircraft encountered uncommanded pitch and attitude inputs that resulted in altitude changes of +/- 100/150 ft. We quickly realized that we had entered the wake turbulence from a Heavy Aircraft in close proximity. The Captain asked for a heading from ATC; while I maintained aircraft control. Once in the clear; I began the descent to 7000. We proceeded to fly the ILS to 27R. Upon landing we were told to give TRACON a call. We explained the situation; fortunately; no one was hurt. We were a little frazzled by the event. I feel as a crew; we could have done a better job of communicating with ATC.
EMB-145 flight crew reported an altitude deviation occurred after encountering wake turbulence on arrival into ORD in trail of a heavy aircraft.