| Flight Spoilers Four flight spoilers are located on the upper surface of each
wing. Each hydraulic system, A and B, is dedicated to a different set of spoiler pairs to
provide isolation and maintain symmetric operation in the event of hydraulic system
failure. Hydraulic pressure shutoff valves are controlled by the two Flight SPOILER
Switches.
Flight spoiler panels are used as speed brakes to increase drag and reduce lift, both in flight and on the ground. The flight spoilers also supplement roll control in response to control wheel commands. A spoiler mixer, connected to the aileron cable-drive, controls the hydraulic power control units on each spoiler panel to provide spoiler movement proportional to aileron movement. The flight spoilers rise on the wing with up aileron and remain faired on the wing with down aileron. When the control wheel is displaced more than approx. 1.7 units, spoiler deflection is initiated. Inflight Speed Brakes The speed brakes consist of flight spoilers and ground spoilers. Hydraulic System A powers all four ground spoilers, two on the upper surface of each wing. The SPEED BRAKE Lever controls the spoilers. When the SPEED BRAKE Lever is actuated all the spoilers extend when the airplane is on the ground and only the flight spoilers extend when the airplane is in the air.The SPEEDBRAKES EXTENDED Light provides an indication of spoiler operation in-flight and on the ground. In flight, the light illuminates to wam the crew that the speed brakes are extended while in the landing configuration or below 800 feet AGL. On the ground, the light illuminates when hydraulic pressure is sensed in the Ground Spoiler Control Valve with the Speed Brake Lever in the DOWN position. In-Flight Operation Operating the SPEED BRAKE Lever in flight causes all flight spoiler panels to rise symmetrically to act as speed brakes. Caution should be exercised when deploying flight spoilers during a tum, as they greatly increase roll rate. When the speed brakes are in an intermediate position roll rates increase significantly. Moving the SPEED BRAKE Lever beyond the FLIGHT DETENT causes buffeting and is prohibited in flight. |