L-1011 Flight Controls: Direct Lift Control (DLC) (27-39)

Spoilers 1, 2, 3, and 4 are used for Direct Lift Control (DLC). The spoilers are driven automatically through the DLC/AGS servo. Here is the DLC engage logic:

• Flaps are set to more than 30º
• At least two throttles are below MCT
• At least two for the throttles are not in reverse. 
• There is no Airplane On Ground (AOG) signal received 
• The airplane is not in go-around mode 
• There is no stall warning 
• The DLC/AGS channels are powered and OK 

The DLC servo that controls spoiler panels 1, 2, 3 and 4 assists in pitch control by reducing the amount of pitch attitude change required to peek the airplane in the "slot" once landing flaps are selected. DLC servo inputs cause the spoilers to travel thereby increasing or reducing lift.

The spoiler handle located on the throttle quadrant follows all DLC inputs providing an indication to the crew of system operation.