The existing seat dynamic performance standards in the Federal Aviation Regulations (FAR’s) have been developed with the primary focus on forward or aft-facing seats, and are not appropriate for the evaluation of potential injuries to occupants seated on side-facing seats (SFS). The purpose of this study was to examine the injury criteria utilized by the automotive industry to assess injuries due to side impact accidents, and to investigate the potential applicability of these methods for side-facing seats in civil aircraft. Several sled tests had been conducted with single and double occupant with the test conditions complying with the 16G, 44 ft/s (13.41 m/s) horizontal impact specified in 14 CFR 25.562. Various side impact injury criteria were evaluated in the tests, including the Thoracic Trauma Index (TTI), Viscous Criteria (VC), rib deflection and pelvis acceleration. Analytical models were developed supporting the test results. Parametric studies had been performed with the validated analytical models to study various factors affecting the injury criteria. Neck loads for the various seating and belt configurations for Hybrid III and SID-H3 or Franken SID (US DoT-SID with Hybrid III head and neck), (MADYMO, 2001), was evaluated by analytical simulations. Inflatable restraint systems were used in reducing the neck injury values below the proposed tolerance limits. Analysis of the data acquired from the tests and observations related to injury parameters from all ATDs are presented. Through the conclusion, most suitable injury criteria are identified. Seating and restraint system configurations that provide maximum protection for occupants on SFS were also identified.