Complex sentence: A later design of the company was the 1983 single-seat Sorrell Hiperlight design for the US FAR 103 ultralight category was sold initially by Sunrise Aircraft of Sheridan, Oregon and was still in production by Thunderbird Aviation of Ray, Michigan in 2015.
Split into simpler sentences: A later design of the company was the 1983 single-seat Sorrell Hiperlight design for the US FAR 103 ultralight category. It was sold initially by Sunrise Aircraft of Sheridan, Oregon and was still in production by Thunderbird Aviation of Ray, Michigan in 2015.