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3 Answers

Calculation for the XC flight(TO, Cruise, LDG)

Asked by: 3499 views Commercial Pilot, FAA Regulations, Flight Instructor, General Aviation, Instrument Rating, Private Pilot

Back in my PPL days, my instructor taught me to do the interpolation by taking difference between two values for the temp and elevation and then reinterpolate with the numbers. Is there any other ways that will help deduce accurate number through mathematical approach ?

 

Steve.

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3 Answers



  1. k-west on Jul 22, 2016

    Interpolation is a mathematical approach, isn’t it?

    http://ncalculators.com/geometry/linear-interpolation-calculator.htm

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  2. Mark Kolber on Jul 22, 2016

    No. If you are looking for =accurate= numbers, interpolation from known values is the mathematical method.

    What else would you suggest?

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  3. Skyfox on Jul 30, 2016

    Interpolation is basically taking an average. For example, the winds aloft forecast is for 3000, 6000, 9000, etc. If you’re planning a flight at 4500 feet, you’d have to look at the forecast for 3000 and 6000 feet and figure a wind speed and heading that’s halfway between the numbers forecast for those other altitudes. If you were at 3500 or 5500 feet, or at an IFR altitude, you’d have to bias it more towards one or the other accordingly. Since forecasts are best guesses and not direct observations, there will nearly always be a difference between the numbers you use and the numbers you experience, so some error is to be expected regardless.

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