I have read the report, thanks for the link. In fact, the infants were unrestrained, and did not use lapbelts. The children were placed on the floor and held there by their mothers, who were in the brace position. Two of the mothers were unable to hold onto their children.
There were four in-lap occupants onboard flight 232.6 Three of them were under 24 months, and one was 26 months old. During the preparations for the emergency landing, parents were instructed to place their "infants" on the floor and to hold them there when the parent assumed the protective brace position. The four in-lap occupants were held on the floor by adults who occupied seats llF, 12B, 14J and 22E. The woman in 145 stated that her son "flew up in the air" upon impact but that she was able to grab him and hold onto him. Details of what happened to the 26-month-old child at 12B during the impact sequence are not known, but he sustained minor injuries. The mother of the 11-month-old girl at 11F said that she had problems placing and keeping her daughter on the floor because she was screaming and trying to stand up. The mother of the 23-month-old at 22E was worried about her son's position. She kept asking the flight attendants for more specific instructions about the brace position and her "special situation with a child on the floor." The mothers of the infants in seats 11F and 22E were unable to hold onto their infants and were unable to find them after the airplane impacted the ground. The infant originally located at 11F was rescued from the fuselage by a passenger who heard her cries and reentered the fuselage. The infant held on the floor in front of seat 22E died of asphyxia secondary to smoke inhalation. The Safety Board addressed the infant restraint issue in Safety Recommendations A-90-78 and A-90-79 issued May 30, 1990.
I cannot imagine that any system which involves unrestrained infants is the safest method. Parents have to pay for their infants from the age of 2 anyway, surely it is not too high a burden to simply say that all children but be booked on the flight and have a seat allocated. All children under either a set weight, or age, must be in a car seat. The parents would in the vast majority of cases have to have a car seat for children anyway, or alternatively the FAA could mandate that airlines carry them for each child booked, in the same way that airlines must accommodate those who require special mobility assistance. Asking parents to "hold on" during an aircraft crash landing seems to be potentially deadly to the infant and to others.