Personaly I dont think such a complex high tech solution would will solve the problem. After all if it can be disengaged or manuplited in any way before the aircraft has landed, then its safe to assume that it will be. Either by pilots forced to give out codes or ground authorities being tricked into releasing the mechanism remotly under the threat that the hijacker will murder everyone on board until they do.
However if a solution is prevented where manipluation or disengaging cannot be performed its going to cause serious problems of false alarms and dangerious situations where the pilot has no control what so ever over the aircraft.
[ 17 September 2001: Message edited by: Captain-Ireland ]