Question 7Gas Turbine - 1st Asst/Chief

The correct answer is A) Stroking the Variable Stator Vanes to the maximum open position. Stroking the Variable Stator Vanes (VSVs) to the maximum open position enhances the effectiveness of an off-line wash of a LM2500 gas turbine engine by allowing more of the wash solution to reach the compressor section. The open VSV position increases the flow path through the engine, enabling the wash solution to better penetrate and clean the compressor blades and stator vanes. The other answer choices are incorrect because: B) Washing the power turbine while still hot would be ineffective as the power turbine is downstream of the compressor section which is the focus of the off-line wash. C) Motoring the engine just short of idle speed would not significantly improve the wash effectiveness compared to stroking the VSVs. D) Applying the power turbine brake would not affect the off-line wash of the compressor section.