On November 1, 2011, about 1730 central daylight time, N30CY, an experimental amateur-built Nusbaum Vaquero airplane, operated and piloted by a private pilot, sustained no damage when the pilot performed a forced landing on an open field near Hebron, Illinois, because the pilot had experienced a medical event in-flight. The personal flight was operating under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the incident. No flight plan was on file. The local flight originated from Hebron, Illinois, at time unknown. According to a McHenry County Sheriff’s Incident/Offense Report, the pilot’s son reported that he had been monitoring his father’s flight. The pilot’s son stated that he saw the airplane land and he went to the field where the airplane had landed. He saw the pilot lying back in the airplane’s seat and the pilot did not appear to be breathing. First responders made their way to the open farm field and two personnel performed cardiopulmonary resuscitation on the pilot. An automated external defibrillator (AED) was applied to the pilot and the AED advised a shock needed to be administered, which it administered. The pilot was subsequently transported to a local hospital. According to Federal Aviation Administration (FAA) records, the pilot held a private pilot certificate. FAA medical records showed that the pilot reported that he had accumulated 4,000 hours of total fight time on the application for his last third-class medical dated May 11, 2001. On that application, the pilot indicated he previously reported that he had “heart or vascular trouble” on prior medical applications and that, he was using Coumadin. The generic name for Coumadin is Warfarin. The FAA Forensic Toxicology's WebDrugs website description of Warfarin indicated it is an anticoagulant medication. N30CY was a high wing, two-place, tailwheel airplane. According to FAA airworthiness records, the pilot provided airplane weight and balance calculations, dated November 5, 2001, which indicated that the airplane’s the gross weight with two occupants would be 1,492 pounds. According to a McHenry County Department of Health Certificate of Death, the pilot died on November 3, 2011. The cause of death was attributed to a myocardial infarction. An autopsy was not performed. Samples for toxicological examination were not taken nor sent to the FAA Civil Aerospace Medical Institute and a Final Forensic Toxicology Accident Report was not produced. The pilot’s son indicated that the pilot had previous heart conditions to include by-pass surgery. He was sent requests to confirm the details involved in the incident and to date has not responded to the requests.