Methods and apparatus are provided for more reliably transferring
operational control for various aircraft flight control surfaces from a
first sub-system to a second sub-system. The present invention provides
an Actuator Control Electronics (ACE) wrap-back module that monitors the
output of the normal mode control module and switches control to the
direct control module based upon the detection of an error condition. The
switching function is controlled by a monitoring system that monitors the
output from an integrated heartbeat module that emits a pre-programmed
signal. The pre-programmed signal is encoded and sent over a
communication bus where it is then decoded and validated by comparing the
decoded signal to the expected results. Any irregularity in the heartbeat
signal automatically triggers a change of control from the first flight
control sub-system to the second flight control sub-system.