Benchmark


Airplane Speed Calculator

Now, with all of this information for the airplane, engine and propeller, you can use the Airplane Speed Calculator.

The calculator shows curves for power required, power available and excess power. It shows the best climb speed and rate of climb, as well as the fuel flow at level flight speed. Familiar charts and controls show the propeller efficiency and engine power.

If you select Full Throttle, the ram air recovery increases the manifold pressure as the airplane goes faster, increasing thrust hp as well.

If you want to change the drag of the airplane to use Benchmark as a design tool or to change an existing design to match your own airplane, you can type a new Cdo value or use the stepper control to change the drag by small increments.

The idea is that you will be able to take a well-tested airplane of the same type (Falco, Mooney, Bonanza, etc) and then adjust the coefficient of drag at zero lift (Cdo) to match the performance of your airplane, and then use Benchmark to print out miles-per-gallon charts for your airplane. It's probable that you will be able to use Benchmark in this way to eliminate all the hard work involved in the drag polar flight testing to quickly produce miles-per-gallon charts for your airplane. All of the aeronautical engineers we have talked to about this think this is probably a good idea, but we will only know how well it works after it has been used in the field on other airplanes. So until it's a well-proven idea, it should be regarded as an engineering concept in the development stage.

 

You may choose Show Details for more information. It now shows the minimum flying speed, the maximum endurance speed and excess horsepower.

     

 

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