Fixed wing turbine powered aircraft means an aircraft that:
Double check valve assembly means an assembly composed of two single, independently acting, check valves including tightly closing shutoff valves located at each end of the assembly and suitable connections for testing the watertightness of each check valve.
Expiry Date (Data di Scadenza) means the Expiry Date as specified in § 1 of the Product and Underlying Data.
Digital Signal Level 0 (DS-0) means the lowest-level signal in the time division multiplex digital hierarchy, and represents a voice-grade channel operating at either the 56 Kbps or 64 Kbps transmission bit rates. There are twenty-four (24) DS-0 channels in a DS-1.
Three-dimensional reference system means a system as described in Appendix 2 to this annex;