DLC on the L-1011
In case nobody has answered your question, The DLC (Direct Lift Control) as you guessed is only in action during approach in landing configuration. When you have the aircraft slowed to approach speed with gear down and flaps in landing position, the spoilers go to a slightly extended position killing some lift and also helping to slow the aircraft with increased drag. On final if you are a bit high and push forward on the yoke the aircraft maintains it's pitch attitude and the spoilers go up a bit more to kill the lift and bring the aircraft back down to the glideslope and in reverse, pulling back on the yoke causes the spoilers to retract proportunate to the yoke movement increasing the lift. The procedure is essentially the same as used by sailplane pilots. The whole purpose is to keep the aircraft in a stable pitch attitude for landing. It made the aircraft a dream to fly and land. The -500 also has MDLC (Manuevering Direct Lift Control) which kept you from overloading the wing roots in a turn at heavy weights. That function, I didn't enjoy, because it felt strange being in a turn and suddenly losing lift. It was a necessary thing structurally for the airplane, but still, it felt strange when it activated.