A Real-Time Monitor to Predict Loss of Control due to Pilot-Induced Oscillations

Pilot-induced oscillations have occurred during early development testing and in operational flight. As awareness of the phenomenon improves, reports of PIOs have become more common, and while most such reports indicate mild episodes, the threat of a severe PIO is always present. With increased use of fly-by-wire technology, and with plans for several possible mega-transports, the potential for PIO will only continue to increase. An on-line flight control system monitor that will detect the onset of loss of control due to PIO will enhance flight safety in the 21st century. The real-time monitor looks at input and response states and compares the input/output relationships with known definitions of PIO. A pilot alert system will notify the flight crew that the event is a PIO and assist in decision-making about the criticality of the event. Such a monitor will benefit pre-production testing as well, as it can be used for envelope expansion, quick-look analysis of stability margins, and even for crew training for PIO idenfication.