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The following material, for viewing in a Java enabled browser, is from the National Aeronautics and Space Administration Learning Technologies Project . While it is loading we suggest you carefully read the instructions below before attempting to manipulate the aerofoil flight test simulation program. It may be advisable to glance through the 'Aerofoils & Wings' groundschool module first.

This is the beta 1.4 version of the NASA Glenn FoilSim II program. Version 1.5 is available for download from the NASA website. FoilSim III is also available.

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With this software you can investigate how an aircraft wing produces lift by changing the values of different factors that affect lift. To return to the original default conditions, click the red Reset button at the left middle of the program. If you experience difficulties when using the sliders to change variables, simply click away from the slider and then back to it.If the arrows on the end of the sliders disappear, click in the areas where the left and right arrow images should appear, and they should reappear.


The program screen is divided into three main parts:


There are two main graphics displays. At the top left is the View window of the airfoil and flow field and at the top right is the Output plot of flow variables.

You can select the type of schematic shown in the View window by using the buttons located around the graphics window. Possible choices are colored blue while the selected option is colored yellow.

You can select the type of plot shown in the Output window by using the white and red buttons on the control panel. If you select "Output Plots", a panel will appear in the output window. Clicking on the appropriate button will provide a plot in the output window. The types of available plots are listed below.


The input variables are located on input panels that are displayed below the Output window. You can select the input to display by using the blue input buttons on the control panel. You can choose to vary the Shape, the Size, or perform a Flight Test. To change the value of an input variable, simply move the slider. Or click on the input box, select and replace the old value, and hit Enter to send the new value to the program. By convention, input boxes have a white background and black numerals, while output boxes have a black background and green numerals.


Interactive output from the program is displayed in output boxes. By convention, output boxes have a black background and green numerals. You can choose to display the lift or the lift coefficient by using the choice button on the control panel. The value is displayed in the output box to the right of the choice button. Lift may be expressed in either English or metric units (pounds or Newtons). On the Flight Test input panel is a group of output boxes that give the atmospheric conditions of the air. The pressure, temperature, and density will change depending on the altitude and planetary inputs. On the Size input panel the geometric aspect ratio of the wing is displayed. The aspect ratio is defined to be the square of the span divided by the wing area and is included here for later calculations of wing drag.


The Learning Technologies Project will continue to improve and update FoilSim II based on user input. Changes from previous versions of the program include:

Groundschool – Flight Theory Guide

| Flight theory contents page | Basic forces | Manoeuvring forces | Airspeed & air properties | Altitude & altimeters |

| Aerofoils & wings | Engine & propeller performance | Tailplane surfaces | Stability | [Control] | Weight & balance |

| Weight shift control | Take-off considerations | Circuit & landing |

| Operations at non-controlled airfields | Safety during take-off & landing |