Further to the statement that the Harrier 1 airbrake was positioned in the mid position by micro switches, i seem to remember there were two switches 24 & 26 degrees which positioned the airbrake depending on whether it was going from up to mid on gear down selection or fully out to mid on gear down selection. These switches were a pain to adjust and the result was often seen on the line with engine running, .............. a chattering airbrake trying to decide if it should be at 24 or 26 degrees!