SPA.RVSM.110 RVSM equipment requirements

TWO INDEPENDENT ALTITUDE MEASUREMENT SYSTEMS Each system should be composed of the following components:

(a)cross-coupled static source/system, with ice protection if located in areas subject to ice accretion;

(b)equipment for measuring static pressure sensed by the static source, converting it to pressure altitude and displaying the pressure altitude to the flight crew:

(c)equipment for providing a digitally encoded signal corresponding to the displayed pressure altitude, for automatic altitude reporting purposes;

(d)static source error correction (SSEC), if needed to meet the performance criteria for RVSM flight envelopes; and

(e)signals referenced to a flight crew selected altitude for automatic control and alerting. These signals will need to be derived from an altitude measurement system meeting the performance criteria for RVSM flight envelopes.