"The design and performance requirements for Child Restraint Systems (CRS) in TSO-C100b and SAE AS5276/1 were developed to enable proper restraint of infants and small children traveling on transport airplanes. They complement and extend those in the Federal Motor Vehicle Safety Standard for Child Restraint Systems (FMVSS-213), which, prior to their development, were the only approval means for CRS used on aircraft. Development of CRS able to comply with the aviation standards has proven challenging, as the test requirements call for a combination of worst-case belt anchor location, belt tension, and seat cushion properties/dimensions that were typical at the time the specifications were written. These parameters no longer appear to be representative of the majority of transport airplane seats. As such, difficulty complying with the standards based on these test parameters may be inadvertently hindering the availability of aviation-specific CRS. Aviation-specific CRS, now commonly referred to as Aviation Child Safety Devices (ACSD), have been recently developed that provide upper torso restraint for forward-facing children. Alternative regulatory procedures have been adopted for certification of these devices, requiring demonstration of an equivalent level of safety with TSO-approved devices. Revision of the regulatory requirements in order to accommodate these new devices included removal of the explicit requirement for these systems to meet FMVSS-213. This action has inadvertently removed some applicable requirements that are not duplicated in the TSO. Such requirements include: design specifications for occupant support surfaces, belt/buckle strength and durability tests, and defined occupant restraint configuration, geometry, and adjustment range. In addition, FMVSS-213 has been revised significantly since TSO-C100b was written, improving several aspects that could benefit existing aviation standards and provide a safety benefit for ACSD. These include use of advanced test dummies, enhanced test dummy preparation and positioning procedures, improved head injury assessment, and better CRS installation procedures. Analysis of AS5276/1, TSO-C100b, FMVSS-213, and the current seat population in the U.S. transport airplane fleet suggests that revisions to both the Aerospace Standard and the TSO based on technological evolution, improvements to test equipment, and test procedures that are more representative of the aircraft environment would advance the development of ACSD while maintaining or improving child safety."--Report documentation page.