Which of the following is NOT listed as one of the basic conditions influencing engine power output?

• A. Temperature
• B. Pressure
• C. Bleed air extracted
• D. Humidity

Answer: (D)

Engine power output is driven by how dense the intake air is and how much air the engine can actually use. The main factors that directly change air density are ambient temperature and ambient pressure: hot air is less dense and reduces power, while higher pressure makes air denser and can increase power. Bleed air extracted from the compressor is another factor because taking bleed air removes a portion of the air that would otherwise contribute to the core’s mass flow, lowering engine power. Humidity affects density too, since humid air is slightly less dense than dry air at the same temperature and pressure, but in this context it isn’t treated as one of the basic conditions that govern engine power output. So humidity isn’t considered a basic condition here.