Abstract: A method and system for use with actuation system to control a plurality of vanes disposed within a turbine engine, wherein a vane position sensor provides a vane position signal corresponding to a vane position of the plurality of vanes, the actuation system includes a plurality of motors engaged in response to the vane position signal, and a differential gearbox having a plurality of inputs operatively coupled to the plurality of motors and an output operatively coupled to the plurality of vanes, wherein an output speed of the output is a sum of a plurality of input speeds of the plurality of inputs.

Abstract: Systems and methods for assessing the health of a first apparatus by monitoring a second apparatus are described herein. A method for monitoring a health of a first apparatus may comprise receiving a performance parameter from a second apparatus, wherein performance of the second apparatus is dependent upon the health of the first apparatus, assessing the performance parameter, and determining the health of the first apparatus. In various embodiments, the performance parameter may comprise at least one of a speed value of the second apparatus, a position value of the second apparatus, a temperature value of the second apparatus, or a time value of the second apparatus.

Abstract: Systems and methods for assessing the health of a first apparatus by monitoring a second apparatus are described herein. A method for monitoring a health of a first apparatus may comprise receiving a performance parameter from a second apparatus, wherein performance of the second apparatus is dependent upon the health of the first apparatus, assessing the performance parameter, and determining the health of the first apparatus. In various embodiments, the performance parameter may comprise at least one of a speed value of the second apparatus, a position value of the second apparatus, a temperature value of the second apparatus, or a time value of the second apparatus.

Abstract: A method and system for use with actuation system to control a plurality of vanes disposed within a turbine engine, wherein a vane position sensor provides a vane position signal corresponding to a vane position of the plurality of vanes, the actuation system includes a plurality of motors engaged in response to the vane position signal, and a differential gearbox having a plurality of inputs operatively coupled to the plurality of motors and an output operatively coupled to the plurality of vanes, wherein an output speed of the output is a sum of a plurality of input speeds of the plurality of inputs.

Abstract: The rate of change of cabin air pressure in an aircraft cabin during aircraft ascent and descent is controlled as a function of a ratio which is equal to (P.sub.ld -P.sub.c)/(P.sub.ld -P.sub.a) during descent, and is equal to (P.sub.cc -P.sub.c)/(P.sub.cr -P.sub.a) during ascent, where P.sub.ld is ambient pressure at the aircraft landing site, P.sub.c is cabin pressure, P.sub.a is external aircraft ambient pressure, P.sub.cc is cabin pressure at cruise altitude, and P.sub.cr is ambient pressure at cruise altitude. A set point value for the ratio is computed throughout aircraft ascent and descent, and compared to the ratio to schedule a variable flow area of an outflow valve in order to drive the difference (i.e., the error) between the ratio and the desired value for the ratio to zero.