Biffle, 55, his wife Cristina, their young son Ryder and daughter Emma were aboard the plane, along with three other passengers, and all seven occupants died in the crash, which erupted into flames on impact.
The former driver, who had a storied NASCAR career with more than 50 wins and later engaged in humanitarian efforts, was mourned by the motorsport community as investigators from the FAA and NTSB begin probing the cause.
