METO power stands for Maximum Except for Take-Off, it is the equivelent of maximum continious EGT or EPR in a jet engine or Max torque in a turbo-prop. It is primarily used in Round Engines. In the DC-3 Takeoff power was either a Max of 48inches or reduced to 45 inches, once airborne you would reduce to METO which is 42 inches and 2550 Rpm, then back to climb power (36 inches and 2325 RPM)