Smoke in the Cockpit: Expressjet Emergency Landing in Chicago (ATC Recording)

On February 4, new, an Expressjet Embraer ERJ-145 operating light UA5828 from Chicago OHare to Ottawa with 38 people on board, was climbing out of OHares runway 04L when the crew stopped the climb at 2100 feet reporting smoke in the cockpit. The crew turned the plane back toward OHare where it landed safely a few minutes later: a problem with the Auxiliary Power Unit was likely the cause of the smoke.