Abstract: A pressure control servo system for regulating cabin pressure in jet airplanes. In the preferred embodiment, the system comprises a first summing network, which sums data from a air data computer (ADC), a flight deck (FD), and a flight management computer (FMC), which produces a pressure reference signal, P.sub.R, indicative thereof. The summing network is connected to both a derivative path, and a proportional path. The derivative path comprises a proportional gain shaper, a derivative, an altitude dependent gain, and a gain multiplier. The proportional path comprises an integral gain shaper, an altitude dependent gain, a gain multiplier, and a rate limit. The outputs of the derivative and proportional paths are then connected to a second summing network, which sums those signals. Then, this summed output passes through a common digital integrator with a limit and a rate limit.

Abstract: An adaptive aircraft cabin pressure control system is disclosed that customizes basic ascent and descent schedules to accommodate variable requirements of specific airlines, the airlines' route structures, and regional air traffic control standards. The system includes an adaptive control logic that identifies a plurality of points generated by the schedules that define ascent and descent curves corresponding to anticipated cabin pressure change rates during ascent and descent. During aircraft flight, the logic samples and stores actual cabin pressure change rates at each of the plurality of points. After the flight, the actual cabin pressure change rates are averaged and the average rate is compared to the anticipated cabin pressure change rate at each point.