(AP) - A medical examiner who performed an autopsy on an 82-year-old pilot was not able to find any medical conditions that could have contributed to the crash that killed all four people aboard, including Oklahoma State University women's basketball coach Kurt Budke last year in central Arkansas. Olin Branstetter's autopsy results, obtained by The Associated Press under a public records request, showed that his death was "essentially instantaneous," but a medical examiner couldn't determine much else because his remains were in bad shape after the crash. Branstetter and his wife and fellow pilot, Paula, were ferrying Budke and assistant coach Miranda Serna to Little Rock for a recruiting trip when their plane went down in a wooded area near Perryville in November. They all died from injuries caused by the crash, according to their autopsy reports. The single-engine plane was flying at about 7,000 feet when it banked to the right, began descending and disappeared from radar, according to a preliminary federal report. The Nov. 17 crash was the second in a decade involving members of OSU's basketball program. Ten people affiliated with the men's basketball team died in a 2001 plane crash in Colorado, prompting the school to enact its travel policy the following year. The Oklahoman newspaper reported in its Thursday editions that Oklahoma State plans to review the university's travel policy because of last year's crash. The school's current policy says student-athletes may not travel in single-engine airplanes while representing the university. Coaches traveling without students can opt to travel in small planes. Using Oklahoma's Open Records Act, the Oklahoma City newspaper obtained documents showing university President Burns Hargis decided to order a new review after corresponding with former Phillips Petroleum Chairman Wayne Allen, an OSU alumnus. "When I was chairman, the Board would not allow me to fly in single engine airplanes," Allen wrote by email to Hargis. When they get the cause sorted out you might consider if it makes sense to have tighter rules. We have had more than our share of airplane accidents. Hargis replied that the school will review the policy "although I already know the push back we will get ... from the coaches." OSU football recruiting director Johnny Barr said there might be times when a coach on a recruiting trip may need to take a small, private aircraft. A separate toxicology report obtained by the AP under the Freedom of Information Act said no drugs were found when workers tested Branstetter's remains. Charles P. Kokes, the chief medical examiner who performed Branstetter's autopsy, cautioned that even if the toxicology tests find the presence of some chemical that wouldn't usually be there, "it doesn't necessarily tell you that there was a problem with the operator. It just points to a potential problem. "In the end, you're just putting together a lot of different puzzle pieces to just try to get the clearest possible picture," Kokes said. And in an instance like this, unfortunately, you're going to have far fewer available pieces. National Transportation Safety Board investigator Jason Aguilera said officials have not found any evidence of carbon monoxide, which can seep into the cockpit from the engine and potentially contribute to loss of control by the pilot. Toxicologists usually test for carbon monoxide, but Aguilera said they weren't able to in this case because of the condition of Branstetter's remains. So, investigators turned to a heating system in the airplane, which could produce carbon monoxide if something went wrong, but didn't find any problems. Aguilera said that means it's "unlikely that exhaust fumes from the engine entered the cockpit." None of the reports determine what caused the plane to fall out of the sky, but they do shed light on some of the pilot and passenger's last moments. Budke and Serna were wearing orange Oklahoma State athletic gear. Budke, who kept his fingernails "neatly trimmed," had a ring on his left hand. Serna was wearing a silver cross - a reminder of her faith that her mother, Nettie Herrera, now has with her in New Mexico. Branstetter - a practiced pilot who took to the skies about 10 times a month alongside Paula - was wearing suspenders. His wife had a pad of sticky notes and a pen in her coat.