Simulated Zero Thrust
It was mentioned earlier, pilots of multi-engine aircraft should be proficient at shutting down the engine and feathering the propeller in flight. Some training maneuvers require simulating an engine failure and this should be done at a safe altitude where possible. At low altitudes such as just after take-off, any training advantage gained in shutting down the engine are far out-weight by the risks involved if mishandled. Therefore, to avoid having to shut down the engine completely, the throttle can be set to simulate zero thrust. If the engine is throttle right back to the idle position, the prop will produce greater drag than when it is feathered, opening the throttle slightly to produce about 11 inches HG manifold pressure, prop drag will be overcome. The actual power setting will vary between each aircraft type and this can be found in the aircraft’s flight manual (POH). With the throttle slightly open, the prop will produce a small amount of thrust equal to the prop drag. A state of balance will then exist with the net result, zero thrust will be simulated.