Cruise Performance Charts

I fly a Cessna 172N, which comes with a POH with lots of information. One of the more useful tables is the Cruise Performance table shown below (Figure 1). The chart gives the fuel flow rate and true airspeed for various combinations of pressure altitude, temperature, and engine percent power. Unfortunately, the table only provides data at the max gross weight of 2300 lbs. Furthermore, my aircraft recently had an Air Plains modification, replacing the existing 160 hp Lycoming O-320-D2G with a 180 hp O-360-A4M, with a commensurate increase in max gross weight from 2300 to 2550 lbs. The Supplemental Airplane Flight Manual has a Cruise Performance table similar to the one provided in the original POH, but it does not include cruise airspeeds! Furthermore, I often fly around at gross weights less than 1900 lbs. What will be the impact on airspeed and fuel consumption with the higher horsepower engine at reduced gross weights? Continue reading

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The Factors in P-Factor

When learning to fly, one of the first things that student pilots learn about is the phenomenon  known as asymmetrical propeller loading, or p-factor. In aircraft with propellers, p-factor causes a yawing moment when the aircraft is at high angles of attack. For most single engine aircraft, this  means that the aircraft will yaw to the left at high angles of attack unless an appropriate right rudder correction is applied. Continue reading

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