Plain English Meaning

It is the planned climb route an airplane is expected to follow if one engine fails during takeoff. The path starts just above the runway and continues upward and outward until the airplane is high enough and fast enough to fly normally on its remaining engine.

Full Definition

The vertical and horizontal track an aircraft is assumed to fly after losing one engine at or after the critical decision point during takeoff, beginning at 35 feet above the runway at the end of the takeoff distance and continuing until the aircraft reaches a height where en route configuration and climb performance can be established. The path is constructed from certified performance data and must clear all obstacles by the required margins.