Complex sentence: On December 6, he spent the day flying model airplanes with his sons; then, after having dinner at his mother's home in Hendersonville, Tennessee, he died of a heart attack at the age of 52.
Split into simpler sentences: On December 6, he spent the day flying model airplanes with his sons and ate dinner at his mother's home in Hendersonville. Later that day, he died of a heart attack, at the age of 52.