In June 2010, a Cessna T310R crashed in fine weather while on final approach at Ruidoso, New Mexico. Five people perished, two survived. The survivors were 12 and 16 years old, and I suspect that they were probably in the aftmost seats. Another young person, an 11-year-old boy, was double-belted in the right front seat with his mother.
Parenthetically, FAR 91.107, which concerns seat belts, does not explicitly forbid the practice of double-belting. The rule says everyone (except children under 2) must occupy a seat with safety belts, but does not stipulate that all passengers be in different seats. After this accident, the National Transportation Safety Board (NTSB) urged the FAA to amend the rule, but the FAA chose not to do so.
