This advisory circular (AC) provides information on certification (design and installation) and continued airworthiness of digital flight data recorder systems (DFDRS). DFDRS provide information for an investigative authority���the National Transportation Safety Board (NTSB) in the United States���to conduct more thorough investigations of accidents and incidents. The data recorded is also used by operators to enable the prediction of trends that may be useful in determining modifications needed to avoid accidents and incidents.

This policy statement communicates the Federal Aviation Administration (FAA) certification
policy on title 14, Code of Federal Regulations (14 CFR) 25.562 and 25.785, amendment 25-64
or later, for side-facing seats installed at angles greater than 18° up to and including 45° from the
centerline of the airplane as measured from the forward direction (oblique seats). This policy
addresses both the technical criteria for certifying oblique seat designs and the implementation of
those criteria. Current FAA research has only been conducted up to the 45° angle; therefore,
seats installed at more than a 45° angle are beyond the scope of this policy.