Steven Nusbaum, 65, was flying an experimental aircraft Tuesday evening in Hebron and made an emergency landing in a farm field when he began to feel ill, the Chicago Tribune reported.
His son -- who had been monitoring the flight and saw the landing -- called police when he found his father lying back in his seat in the airplane.
Paramedics resuscitated Nusbaum by giving him two shocks with an automated external defibrillator, police said. He was transported to Centegra Northern Illinois Medical Center where he was initially listed in critical condition.
Police said Nusbaum had stabilized by Wednesday morning.