The FAA didn’t get serious about seatbelts until 1978, and even then it was only requiring shoulder restraints for the front seats. Ten years later, they added the rear. Given how long aircraft stay in service, that means there are thousands of craft flying every day with inadequate protection for the most valuable item on board.
If you’re flying with only a lap belt—shame on you. As much as some pilots don’t like having belts over their shoulders, the study data has been clear for decades: 88 percent of injuries and 20 percent of fatalities can be eliminated by adding shoulder or additional restraints over lap belts alone, according to the the FAA.