Plain English Meaning

The specific loading of the airplane — how heavy it is and where the weight sits along its length — that makes it hardest to control if an engine fails. For VMC testing, this is usually as heavy as allowed with the load placed as far back as allowed.

Full Definition

The combination of airplane weight and center-of-gravity (CG) location that produces the worst-case handling and controllability when one engine is inoperative on a multi-engine airplane. For VMC determination, this is typically the maximum takeoff weight with the CG at its most rearward approved limit, because an aft CG shortens the rudder's moment arm and reduces its ability to counter the from the operating engine.