Abstract:
A multi-function air data sensing probe has a strut that is mounted on an aircraft and extends laterally from the aircraft skin. The strut is supported on a base plate, and has a pitot pressure sensing tube at the outer end thereof, with a pitot port facing upstream, and also includes a passageway for total air temperature sensor including a forwardly facing inlet scoop that leads to a chamber in the strut that is laterally offset from the inlet scoop so that flow changes direction as it enters the chamber. The surface defining the change of direction between the scoop and the chamber is provided with bleed holes for bleeding off boundary layer air. A vane type air data sensor is mounted on a shaft that rotates freely and is supported on the strut, and is positioned to sense the relative air flow past the strut to determine changes of relative angles of such air flow. In addition, the strut has static pressure sensing ports on lateral sides thereof leading to a separate chamber on the interior of the strut.
Abstract:
A method of detecting errors in air data sensing systems having multi-function probes being used in combinations to define probe systems includes a step (A) of, for each probe system, making a first prediction of an aircraft parameter as a function of local angles of attack at two member probes of the particular system, and making a second prediction of the aircraft parameter as a function of local pressure ratios at the two member probes of the particular system. A step (B) is performed in which, for each of the probe systems, the first and second predictions of the aircraft parameter are compared to determine whether the first and second predictions are within a predetermined threshold of each other. Then, a step (C) is performed in which, for each of the probe systems, if the first and second predictions of the aircraft parameter are not within the predetermined threshold of each other, then the particular probe system is identified as having a malfunctioning member probe.
Abstract:
A multi-function probe system (14, 16, 18, 50, 70) that provides redundancy for measurements and compensates for effects of sideslip of an aircraft (10) includes at least two probes (14, 16) that are symmetrically located on the opposite sides of the aircraft, and a third probe (18, 50, 70) mounted on the centerline (20) of the aircraft (10) positioned to directly measure local sideslip, in one form (18, 50) of the third probe with ports (60, 62) that are positioned on opposite sides of the center plane of the aircraft. Each of the probes (14, 16, 18, 50, 70) includes self contained instrumentation (14D, 16D, 18D, 38) for providing signals indicating various pressures. The local angle of sideslip sensed by the third probe (18, 50, 70) is used as a compensation for pressure readings at either of the other probes (14, 16) for determining actual angle of attack, and static pressure.
Abstract:
A method of generating, for an aircraft, a total air temperature compensated for recovery or deicing heater error includes measuring a total air temperature (MEASURED TAT 18) with a total air temperature probe. A local angle of attack for the total air temperature probe is determined (110). Then, a corrected total air temperature (CORRECTED TAT), compensated for recovery or deicing heater error, is generated (130) as a function of the measured total air temperature and the determined local angle of attack for the total air temperature probe.