Is there an aircraft in which the spoilers are actuated by bringing throttle(s) to full retard? Or is it my imagination?
Full retard on a Dash 7 would be full reverse, a place where most pilots would not get to very often (potentially damaging to the aircraft). Full retard on many other types would be idle power, which can also be used in flight (where spoiler use is not ideal, in most cases).
I have limited knowledge of systems in which spoilers are actuated by a combination of power lever position, and weight on wheels switches. This was an element of a serious crash of a DC-8 operated by Air Canada decades ago, where the aircraft was bounced on landing, deploying the spoilers, and attempted to fly away with fatal results. The undesired operation of the spoilers contributed to the crash as I recall.
Spoilers are a great system for control of the aircraft, but their operation, or failure to operate as desired, has serious safety considerations. This, in particular, because, in many cases, the position of the spoilers cannot be seen by the pilot. Most aircraft would have spoiler position indicators. I did once fly a Mooney, whose spoilers (speed brakes) had a mind of their own. It was not a big deal though, as their effect on the flight of the aircraft seemed very limited anyway!
Sorry to dash (pun intended) your patent ideas... I don't think you want the liability of this one!
Pilot DAR