The Allison T56 turboprop engine is rated at 4,910 equivalent shaft horsepower at zero velocity at sea level. Consider an airplane with this engine flying at 500 ft/s at sea level. The jet thrust is 250 lb, and the propeller efficiency is 0.9. Calculate the equivalent shaft horsepower at this flight condition.
\[P_{eq,shaft} = P_{shaft} + P_{Thrust}\]\[P_{shaft} = 4910\]
\[P_{Thrust} = \frac{T_{j}V_{\infty}}{\eta _{p}} = \frac{250\left ( 500 \right )}{ 0.9} = 138888.89\]
\[\Rightarrow P_{eq,shaft} = 4910 + 138888.89 = 143798.89\]
