Moderators: richierich, ua900, PanAm_DC10, hOMSaR
Avatar2go wrote:Just speculating, but perhaps the changer doesn't care whether the spoilers are stowed by the speed-brake lever. It commands right spoiler drop for left wheel turn, in all cases. If the spoiler is stowed, then no impact. If not stowed, then the changer has the desired effect on the right spoiler.
The "don't care" state is common in control system design of complex interacting systems. In this case, the purpose of the changer is to enhance roll authority with spoilers in any position.
Unlike the ailerons, the spoilers can affect vertical flight in only one direction (raise above the wing but can't drop below). So that would seem to necessitate the "don't care" state for control inputs in the opposite direction.
kalvado wrote:As for maintenance manual, this weak signal may be a good diagnostic metric for some reason. For example, weak can become zero if there is any problem with flow or alignment...
milhaus wrote:Today i had possibility to check system behavoir on real aircraft, cables from mixer definitely move to both direction. Via quadrant they move valves inside actuator but spoiler remains in the same position, it is already at downstop. I think that valve inside actuator is fully open when spoliers are stored, there was no feeling that it gets more pressure from aileron signal.