Definition
A power setting on the inoperative engine of a multiengine airplane that produces no net thrust and no significant drag, used during training to simulate the effect of a feathered propeller without actually shutting the engine down. It allows the instructor to replicate engine-failure handling characteristics while keeping the engine running and available.
Plain English
A throttle setting on the 'failed' engine that makes it produce neither push nor drag, so the airplane behaves as if that propeller had been feathered. The engine is still running, just set so it has no effect on performance.
Context Anchor
Used during simulated engine-failure practice in multiengine airplanes, especially when an instructor wants to practice one-engine handling without actually shutting an engine down.
Derivation
Zero-thrust' literally means producing no forward thrust. The setting is named for what it achieves — neither pulling the airplane forward nor dragging it back — rather than for a fixed throttle position.
Why Pilots Care
It lets pilots safely experience and respond to the yaw, drag, and performance loss of an inoperative engine without the added risk of a full engine shutdown.
Grounding Statement
In training, a small amount of power may be left on the simulated failed engine so its propeller is not pulling and is not strongly braking the airplane.
Intuition Check
Zero-thrust does not mean the engine is off or the throttle is fully closed. It means the running engine is adjusted so its propeller has about no net push on the airplane.
Example Sentence 1
During the training flight, the instructor reduced the right engine to the zero-thrust power setting to simulate an engine failure after takeoff.
Example Sentence 2
Reference the POH to find the exact zero-thrust power setting for your airplane before the training flight.