Definition
A specifically designed departure procedure for use after the loss of one engine on takeoff that ensures the airplane will clear all obstacles by a required margin while climbing on the remaining engine(s). It is developed by the operator using the airplane's actual one-engine-inoperative climb performance, and may differ from the standard instrument departure (SID) flown when all engines are operating.
Plain English
A pre-planned escape route to fly if an engine quits during takeoff. Because the airplane climbs much more slowly on one engine, this special route is designed to keep it safely above terrain and obstacles until it can climb high enough to continue normally.
Context Anchor
You see this during departure planning for multi-engine aircraft, especially when checking what the crew will do if an engine fails after takeoff.
Derivation
“Engine-out” is aviation shorthand for an engine being out of service, not physically gone. “Obstacle” comes from an older root meaning something that stands in the way, and “procedure” means an ordered way of doing something. Together, the phrase points to a planned way to fly when one engine is out and something is in the aircraft’s path.
Why Pilots Care
Allows safe continuation of flight rather than an immediate forced landing or collision when performance is suddenly reduced.
Grounding Statement
Picture losing an engine just after liftoff: the airplane may still climb, but more slowly, so it may need a different planned path to stay away from obstacles.
Intuition Check
“Engine-out” does not mean the engine has fallen off or that the aircraft cannot fly. It means one engine is not producing usable power, so the takeoff path must be planned for reduced climb ability.
Example Sentence 1
During the takeoff briefing, the captain reviewed the engine-out obstacle avoidance procedure, which called for a left turn to a holding fix instead of the straight-out departure.
Example Sentence 2
During the takeoff briefing the crew reviewed the engine-out obstacle avoidance procedure in case of failure after V1.