Integrated aircraft air data system

Abstract

An integrated air data system for use on an aircraft. Airframe air data units (18) are connected to receive a plurality of redundant total pressure sensor inputs (20,22,24), a plurality of redundant static pressure sensor inputs (26,28,30), and a total temperature sensor input (32). Similar redundant sensor inputs are provided a first and second channel in each of two electronic engine controls (34,36). Bidirectional data buses (16) connect the airframe air data system to the electronic engine control system, so that the same sensor signals are available for each of the systems. The airframe air data unit and the primary electronic engine control channel having priority to control each engine are independently operative to select a preferred total pressure, static pressure, and total temperature value according to a common programmed logic scheme. The selection logic gives priority to the use of the same value for common parameters in each of the systems, where possible. The logic also minimizes the risk that failure of a single sensor may result in use of an incorrect value for a parameter, and that any combination of failures of different sensors, except for similar failures occurring independently on each engine, might result in an undesired effect on more than one engine.