MD-11 has an optional Weight and Balance System (WBS) and requires the following conditions:
- Wind velocity less than 25 kts
- Fuel and engine ignition switches off
- Cargo and passenger loading complete
- Tug not attached
- Fuel scheduling and system testing complete
Two weight and balance computers control, operate and test the WBS. GW, CG and ZFWCG of both W/B computers are compared and averaged to obtain output data that is transmitted to the FMCs.
.... however, I never seen it working.