Southern Star Avionics has completed required flight testing for Cessna Citation 560 and S550 airframes and expects to receive RVSM group certification for the types early next month. The $95,000 installation kits use IS&S digital altimeters with integrated air-data computers and analog interface units. The company said the upgrade is available for both single and dual flight director aircraft equipped with Sperry SPZ-500 autopilots. Standard equipment provided with the kit includes air-data display units, an analog interface unit, a prefabricated wire harness, circuit breaker panel, pitot-static kit and the hardware needed for installation. Mobile, Ala.-based Southern Star recently gained approval for a similar installation in the Cessna Citation 500/550 and SP series.