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.
Plain English
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.
Context Anchor
Seen when planning multiengine IFR departures and checking whether the airplane can clear terrain, towers, or other obstacles after an engine failure on takeoff.
Why Pilots Care
It guarantees obstacle clearance and regulatory compliance during the critical takeoff phase with reduced power.
Grounding Statement
Picture the airplane lifting off, losing one engine, and still needing a known path that climbs above every obstacle ahead.
Intuition Check
Do not read this as the normal takeoff path with all engines working. It means the reduced-performance path after one engine has failed, and it includes both where the airplane goes and how well it climbs.
Example Sentence 1
Before departing the high-elevation airport, the crew calculated the OEI takeoff flight path to confirm the aircraft would clear the ridge east of the runway at their planned takeoff weight.
Example Sentence 2
During certification testing, the aircraft demonstrated it could follow the required OEI takeoff flight path with adequate margins.