Roush was piloting the Beechcraft Premier business jet at the Experimental Aircraft Association's AirVenture Show at Wittman Airfield in Oshkosh, Wisconsin. He crash-landed the plane around 6:15 CDT according to the EAA.
The plane was carrying one passenger, Brenda Strickland, who is a friend of Roush's, according to Roush Fenway Racing spokesperson Lori Halbeisen. Both Roush and Strickland walked away from the crash and were taken to a local hospital.
"He was conscious when he was admitted to the hospital," Halbeisen told ABCNews.com.
As of this morning, Halbeisen said Roush's condition was "serious but stable."
"All his injuries are non-life threatening," she said.
Strickland also appears to be OK.
"She's also being treated for non-life threatening injuries," Halbeisen said.
Halbeisen said there was not yet a timetable for his recovery because doctors are still evaluating his condition. Roush's family is with him now, and he has not yet spoken to anyone at Roush Fenway Racing.
The National Transportation and Safety Board is investigating the crash. Halbeisen said there was no information relating to the cause of the crash landing.
Roush owns 3 aircraft and has been flying for many years, Halbeisen said. One of those aircraft is a vintage World-War II era P-51 Mustang, according to the Associated Press.
"He's a very experienced pilot," Halbeisen said.
Roush is a former Ford Motor Co. employee and college physics teacher who founded his first NASCAR race team in 1988. Since then, Roush Racing has grown to become the largest race team in NASCAR with 8 motorsports teams, joining with Fenway Sports Group in 2007 to become Roush Fenway Racing.
Roush's teams have won 5 championships across NASCAR's three premier divisions, the latest in the Nationwide Series with Carl Edwards in 2007.