ORD Controllers reported an air carrier aircraft initiated a wrong turn resulting in controllers taking expedited measures to maintain separation with two other departing aircraft. Controller stated that this is an extremely unsafe situation that has become a chronic problem.

Reporter 1

I was landing RWY 10C and departing RWY 10L at the end of the evening. I issued Aircraft X a takeoff clearance with a right turn heading 180. The pilot read back "right heading 180". The aircraft rolled, and after 6,000 feet and airborne, I rolled Aircraft Y on a 090 heading. Meanwhile, the North Local Controller (NLC) Controller rolled Aircraft Z on a left 070 heading. I was looking at the radar when the Aircraft X tag acquired, and it looked a little north of the runway centerline depicted on the radar, and continuing to turn left, despite a correct readback of a right turn. It was IFR, and the plane was in the clouds. I immediately coordinated with the NLC Controller to stop their plane at 2,500 feet (underneath the altitude Aircraft X had climbed out of at that point) and stopped my own departure at 2,500 feet as well. I corrected Aircraft X's turn with a right turn to the south, and issued traffic to Aircraft Y. There was no loss of separation, but wrong direction turns are a chronic problem here, even when the pilot gives the correct readback. I have no idea. The pilot read back correct instructions, and then did an incorrect thing.

Reporter 2

I was working NLC, which at the time controlled departures off of Runway 9C. I cleared Aircraft Z for takeoff, on a 070 heading assigned. The weather was IFR, with ILS critical ceilings. As Aircraft Z was rolling, I noticed Aircraft X, a southbound departure off of Runway 10L, on the radar starting what appeared to be a wrong turn to the north, moving into the departure corridor of Runway 9C. I immediately began coordination with 3LC, who controlled Runway 10L, and instructed Aircraft Z to stop their climb at a safe altitude below Aircraft X. I then turned Aircraft Z to a 360 heading, to provide more airspace for 3LC to ensure separation with successive departures. Once 3LC had Aircraft X back on course, I turned Aircraft Z back to a 070 heading on course. No loss of separation was observed between any aircraft, and the review of the tapes determined it was a pilot deviation. Aircraft Z was issued and read back a right turn heading 180, but turned left. Wrong turn departures continue to be a chronic problem at ORD. Departing parallel runways, especially in IFR weather when the aircraft cannot be visually observed in the turns, continues to introduce a very high level of risk. It is my opinion, and the opinion of many at ORD, that the only way this process will be seriously addressed is AFTER a tragic event takes place. This is not an unknown issue, it is an extremely unsafe situation that has been brought up for years, and still no changes are in the works.