A study is made on the kinematics of an occupant in a side-facing aircraft seat. Certification of side-facing seat is made mandatory requiring equivalent level of safety compared to the conventional forward-or aft-seats. A number of side-facing seat impact sled tests were conducted using SID on a rigid divan type couch facing a rigid bulkhead to maximize the potential for injuries. Appropriate injury criteria were identified and recorded in the tests. Studies were conducted for single and multiple occupants' seats with Hybrid II as second occupant. Analytical models were developed supporting for the sled test results and a set of parametric studies were conducted using the developed analytical models. Through the conclusion, the related injury and pass/fail criteria and the most appropriate testing procedures for certification of these seats along with some simple guidelines to meet this certification were outlined.