For an airplane with specified gross weight and cruise speed, how does fuel flow relate to temperature and altitude?

The relationship between fuel flow, temperature, and altitude is based on principles of aerodynamics and thermodynamics. As altitude increases, the air becomes less dense, which affects engine performance and fuel requirements. In general, engines produce less power at higher altitudes due to the lower air density, which can lead to a need for more fuel to maintain a specified power output or cruise speed.

When the temperature increases, the density of the air also decreases. In this case, the engines might not receive enough air to produce the same power at a given weight and speed. To compensate for this, fuel flow must increase to maintain proper combustion and power output in the engine.

Therefore, lower temperatures and lower altitudes typically lead to higher air density, resulting in a decrease in required fuel flow since the engine can operate more efficiently. Conversely, higher temperatures and higher altitudes lead to reduced air density and a need for increased fuel flow to deliver sufficient thrust and maintain performance.

The correct interpretation is that fuel flow is indeed higher when the temperature is increased and altitude is decreased, as this reduces air density and pressurization in the combustion process, thereby requiring more fuel to sustain the necessary energy output. Thus, under conditions of decreased air density, an increase in fuel flow