Purpose and Scope This document contains Minimum Operational Performance Specification (MOPS) of ACTIVE on-board INFLIGHT Icing Detection Systems (FIDS). This MOPS specifies FIDS Operational Performance which is the minimum necessary to satisfy regulatory requirements for the design and manufacture of the equipment to a minimum standard and guidance towards acceptable means of compliance when installed on an AIRCRAFT. Detection of ICE accreted on the AIRCRAFT during ground operations is not considered in this document. This MOPS was written for the use of FIDS on AIRCRAFT as defined in 1.3 and 2.3. Expected minimum performance specifications for FIDS and their FUNCTIONS are provided in Section 3. The minimum performance requirements as defined in Section 3 do not consider SYSTEM performance as installed on the AIRCRAFT. Performance in excess of the minimum performance may be required by the SYSTEM installed on an AIRCRAFT in order to meet regulatory or operational requirements. This topic is considered in Section 6. This MOPS document is structured as follows: