At 10:30 a.m. Chicago time, the fighter jet, which was already in the air over Gary, Ind., came across a multi-colored Cessna in air space that is part of a no-fly zone due to the president's visit to Chicago.
That small plane then exited the area, NORAD said, without radio communications.
An FAA spokeswoman said the small, private aircraft landed in DeKalb. No other information was released.
