This document has been declared NONCURRENT. It is recommended, therefore, that this document not be specified for new designs. NONCURRENT refers to those documents which have previously been widely referenced and may continue to be required on some existing designs.This Aerospace Standard establishes the essential minimum safe operational performance requirements for gyroscopically stabilized pitch and roll indicating instruments for use with reciprocating and turbine engine powered aircraft. This Aerospace Standard covers two basic types of pitch and roll indicating instruments as follows: Type I: Direct coupled to gyro; Type II: Electrical repeating.