January 21, 2009

# Useful Formulas used with Flying Model Aircraft

The formulas presented on this page should be helpful to newcomers to the hobby.  These are fairly basic and easy to calculate formulas that will give a good indication of what to expect from an aircraft before flying it for the first time.

Some of these formulas depend on a rudimentary understanding of Trigonometry.  I have attempted to explain just what you need to know as simply as possible.

## In this series

Please note that the above articles do not describe how to choose the correct parameters for your model aircraft design.  The series teaches you how to do the math to convert angles to measurements, calculate areas, etc.

If you want to learn how to determine the correct amount of side thrust, the correct wing dihedral or similar information then you will need to consult a trim chart.

Before you can even begin to trim your model you must locate the correct Center of Gravity.  If you fail to do this then any other trim adjustments you make will be wrong.

## Trimming a Radio Control Model Aircraft

• An excellent unit converter by Josh Madison.  This is a freeware program that will convert just about any unit to any unit.

• Another way to convert units is to simply type your question into Google.  I found this by accident by simply deciding to try it.  Go to the Google homepage and type the number of units and the unit type into the search box.  Then type "to" and the units you want to convert.

• Beginner's Guide to Aerodynamics The NASA site contains theory and fun projects for kids.

# Please Excuse My Whining Dept.

Quick!  Think of an odd number greater than 20...............  Got it?  OK, divide that number by 16 in your head to determine the decimal equivalent.......

tick...

tock...

tick...

tock...

Have an answer?  How long did it take you to figure it out?  Now divide the same number by 10.  See how easy that was?  Call your Congressman and Senators and demand that we switch to the metric system immediately.  16ths suck!  Down with 16ths!  Power to the Millimeter!

OK, sorry.  I'm done now.

American model aircraft designs use Imperial (inch) measurements inflicted on us by some British King who was probably long dead before Mr. DaVinci invented the flying worm gear.  Kingy thought standard measurements should be derived from his body parts he was wrong.  Until metric wood sizes come to America, we're pretty much stuck with imperial measurements, so in an effort to be a team player I will be using them in the various examples on this page.  European kits give metric measurements and may or may not include inch equivalents.

OK, sorry.  I really am done now.

## In this series

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