L-1011 Flight Controls: Active Controls Load Distribution (27-51)

In the illustration above the dotted line shows the basic wing lift design load distribution of the L-1011 wing. the solid line shows the redistribution produced by symmetrical upwards deflection of outboard ailerons. Both load distribution lines are for the same structural design wing lift but the redistribution line show how aileron deflection moved the center of pressure inboard thus lowering the wing root bending moments. During cruise, aileron deflection would be minimal.

the Active Control System (ACS) uses outboard ailerons symmetrical deflection to relieve wing loading. Aileron deflection is controlled by accelerometer and sensor signals delivered to the ACS computer and from there on to the aileron servo. The computer provides the following functions:

• Maneuvering Load Control (MLC) by redistributing air loads caused by maneuvering air gusts inward span wise toward the wing root. 
• Elastic Mode Suppression (EMS) - Reduces vibrations along the wing in response to the wings natural bending vibration frequency. 
• High Lift Control (HLC) or wing tip relief when in the high lift, high drag flaps and slats extended configuration. (Both outboard ailerons will be up 8º).