What are the ideal wind and humidity conditions for accurately trimming gas turbine engines?

The ideal conditions for accurately trimming gas turbine engines are characterized by no wind and low moisture. When there is no wind, it ensures a stable environment for the measurements being taken, eliminating any potential variations that wind could introduce to the engine's performance metrics. Additionally, low moisture is crucial because high humidity can affect the combustion process and lead to inconsistent performance readings. Moisture can create issues with fuel absorption and vaporization, resulting in inaccuracies when measuring engine output. Therefore, having low moisture ensures that the fuel-air mixture remains optimal, allowing for precise trimming of the engine's fuel metering system.