This study is aimed at developing requirements for certification criteria and verification techniques for side facing aircraft seats. Presently flying side facing seats were inspected and analyzed. Results from automotive safety research were used and transferred to aircraft. For lateral strain direction, on the one hand human tolerance, and on the other hand injury criteria such as head, cervical column, thoracic/lumbar column, thorax, pelvis as well as upper and lower extremities were compiled from literature. The particularities of side facing seats were inspected with two dynamic tests, and proposals made for the requirements of certification criteria and verification techniques.