NEW : Official FAA investigators have spoken with two of the pilots . NEW : The aircraft was involved in an accident in 1997 . Autopsies show those killed in plane crash suffered blunt force trauma . The condition of the former crew members has been upgraded from critical to serious .
NEW : Official says investigators have spoken with two of the survivors . NEW : The pilot was involved in an accident in 1997 . Autopsies show those killed in plane crash suffered blunt force trauma . The condition of the former NASA chief has been upgraded from critical to serious .