Abstract: A system and a method for detecting a hard landing or other high load event of an aircraft and then automatically triggering a report of such hard landing event. A sink rate algorithm is used to estimate the altitude rate of a main gear. The sink rate algorithm uses a plurality of flight parameters to estimate the main gear altitude rate, preferably including at least the following: pitch altitude, radio altitude, vertical acceleration, body pitch rate and vertical speed. This invention has the potential to reduce the number of unnecessary structural inspections, and may also limit the scope of any such required inspections.

Abstract: An air data computer outputs a data stream indicative of measured airspeed of an aircraft, for use in generating a display of airspeed to a pilot. To correct for the inherent processing delay, a correction factor is added to the data stream, so that the display is more closely related to the actual airspeed of the aircraft at the time of the display. The correction factor can be calculated by determining the average rate of change of airspeed during a preceding time interval and multiplying the average rate of change by the processing delay.

Abstract: A fault-tolerant air data and inertial navigation reference system utilizes skewed axis inertial sensors and fault-tolerant redundant electronics to provide higher redundancy with fewer parts. Parallelly operating processor circuits each receive the individual outputs of six skewed-axis gyros and six skewed-axis accelerometers. Each processor independently processes parity equations using the outputs to identify malfunctioning sensors. Further, the output of each processor is transmitted to three parallelly operating voter circuits. The voters are operable to discard a processor if its output does not agree with the majority. The voter outputs are similarly fed back to the processor circuits, which compare these outputs, and discard any voter whose output disagrees with the majority, thus providing a completely integrated 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.