Speed & Climb Rate Graphs

Discussion in 'Technical Requests' started by Zipper730, Jan 6, 2017.

  1. Zipper730

    Zipper730 Member

    Nov 9, 2015
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    It's amazing how the charts and graphs from nation to nation and even within different branches of a nation vary: The US Navy for example generally have pretty well written charts, often easy to read and things of that sort; the US Army Air Force on the other hand has some quality issues, some of them are damned near illegible.

    I'm curious if anybody has ever transcribed the graphed data for speed across the altitude range (engine power, true airspeed with position error corrections), and climb-rate (engine power, true airspeed with position-error correction) up to the service ceiling and stuff like that into graphs that are of high quality and easily legible.
  2. GregP

    GregP Well-Known Member

    Jul 28, 2003
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    Electrical Engineer, Aircraft Restoration
    Rancho Cucamonga, California, U.S.A.
    As far as I know, there are no sources that "collect" these data in one place. Anyone who did would have very good material for a book that could be profitable if it turned out to be mostly correct. Part of the problem is most US and British sources have data every 5,000 feet and most German, Soviet, and Japanese data you can find are at units of 1,000 meters, so there are no charts that speficy the data at the same altitudes and units as the other side.

    To collect the data, you'd need one set in English units and one in metric, and the the speed and climb charts where the supercharger has to change speeds will all need to be done manually and they don't follow a smooth curve. They would need piecewise equations for the segments taht follow a function line. I's estimate maybe 4 equations for a 2-speed supercharger, with boundary conditions specified to assure no chart discontinuities.

    It's certainly doable, but will take a lot of work!

    If I did it, it would very certainly not be supplied as a "freebie!" But I'd advertise that it was available, for sure, in printed form only. Once you release an electronic copy, you'll see almost no more sales! I know too many people who have had that happen to them.
  3. tomo pauk

    tomo pauk Creator of Interesting Threads

    Apr 3, 2008
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    Jeff (Corsning) has the data, posted mosty on this forum. The speed and climb rate is listed per each full kilometre, starting with sea level. Tabulating the data into a spreadsheet should not be the problem, apart from the time used, and spreadsheet programs can derive graphs from that.
    Engine power at range of altitudes is a bit of problem, since the power graphs do not involve ram effect, while aircraft flying at speed invoke the ram effect. Nothing big of a problem, but care should be taken.

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