AircraftDesign.com

RDSwin Tips, Tricks, and FAQs

Updated 10-20-26 …. finally!

Here are tips and tricks on the use of RDSwin, including answers to FAQ’s. Most of these initial tips are available in the pop-up User’s Manual, so the first tip is…Read The Friendly Manual! If you have specific questions or tips to suggest, send them to Aircraft Design Research LLC .

(Note: the information below is provided with the best of intentions but please consult an expert before modifying any computer settings. This website, ADR, and Dr. Raymer assume no liability if these suggestions don’t work or cause other problems!)

Installing RDSwin

To install RDSwin-Student, download the zipped file as purchased from AIAA then ExtractAll into your own user folder (such as C:\Users\DanRaymer\). If it ask you for a password, use RDS4AIAA. Then set up a Windows Shortcut using Windows Explorer. In your new main RDS directory, find and right-click on the program file RDSwin.exe and select SendTo-Desktop. RDSwin is then ready for use. Now just click on the Shortcut icon to start RDSwin. See below for more on the Shortcut, including adjustments to Parameters that may be required on some computers.

Once in the program, click on Tutorial Sessions in the Help pulldown menu tab. These will get you started. RDSwin is a rather sophisticated program with a lot of features and menu options. A complete PDF users manual is also there. The different modules have their own help popup boxes – press H in most screens or click on data column headings.

 Today’s computers have a wide range of security software to protect against viruses and malicious software, and to protect companies from installation of unauthorized or pirated software on their computers. Depending upon the security methods in use, there may be problems getting RDSwin to run the first time. Since RDSwin is not used widely enough to be flagged as “normal” by security software, it may be flagged as “suspicious.” If so, you may have to open the security software and give RDSwin permission to run. You may need to install RDSwin while logged on to Windows as “Administrator.” You may need to “Unblock” it using My Computer or Windows Explorer. Right-click on RDSwin.exe, go to Properties, and click UnBlock.

RDSwin is not intended to be installed on a network and will almost certainly not work if that is attempted. The license specifically prohibits this, so don”t be surprised when it doesn”t work! 

If you are installing RDSwin-Professional, the first time you run it a message will appear with an alphanumeric code generated from parameters in your computer system. Email this to the address provided and an unlock code will be sent to you. This must be entered only one time. 

RDSwin Desktop Shortcut

Once you have created your RDSwin Shortcut by right-clicking on the Exe, you can make it look nicer. Right-click on it, select Rename, and change “Shortcut to RDSwin.exe” to simply “RDSwin” or “RDSwin Student”. Under Shortcut Properties, you can change the ugly default Icon. Several RDSwin Icons (.ico) in various colors can be found in the RDSresource directory with filenames such as RDSwinIconGreen.ico. 

On some computers, you’ll have to make certain adjustments to the Shortcut Properties to get it to run properly. See below.

Always Store Your RDSwin User Files in Your Windows User Folder

Windows System Restore, a nice utility to have when your computer starts acting strangely, can unfortunately “restore” your RDSwin design files to the old copies from weeks ago. During a Restore, files on your computer revert to the versions at the last Restore Point except those that reside in your own Windows User Folder. So when saving your RDSwin design files, you should create and use a directory at C:\Users\[yourusername]\….

The C:\Users\ part may be different for your version of Windows – look for something similar.

Running RDSwin under 64-bit Windows

…should be no problem for a 32-bit application like RDSwin. According to the Microsoft website , ‘Most programs designed for the 32-bit version of Windows will work on the 64-bit version of Windows. Notable exceptions are many antivirus programs (and) device drivers designed for the 32-bit version of Windows’. RDSwin isn’t an antivirus program and it doesn’t contain its own device drivers, instead using the ones installed on your computer for printer, monitor, mouse, and the like. 

If you do experience trouble, it’s probably from another cause. See below.

Running RDSwin under Linux or on a MAC

RDSwin should run under Linux or on a MAC using WINE, a free open-source program that allows Windows programs to run on non-Windows computers. You aren’t supposed to call it an “emulator” and in fact, WINE is said to be an acronym for “Wine Is Not an Emulator.” The WINE website calls it a “compatibility layer capable of running Windows applications on several POSIX-compliant operating systems.” Whatever. It works, and it’s free. However, ADR cannot guarantee that all RDSwin functions will work properly under WINE or any other emulator.

RDSwin-Professional will probably not work under Linux or on a MAC due to the security system employed. Potential customers should contact ADR to discuss options. Or just purchase a low-end Windows PC for running RDSwin-Pro.

If RDSwin won’t run

RDSwin has built-in error checking for likely problems, with pop-up descriptions to help you resolve any issues. But if it won’t run, or won’t run properly, check here:

Nothing Happens on First Use:

 The most obvious problem – no offense – is that you have copied RDSwin from another user’s computer rather than installing it from your own downloaded zip file. Don’t do that. RDSwin can tell. Another possibility – you have somehow deleted or corrupted some of the required DLL’s and resource files. Reinstall from the zip file. Possibly your security software doesn’t like RDSwin, and is stopping execution but isn’t warning you. See the above note on security software.

Nothing Happens, or Main Menu Page Opens but Nothing Works: 

You may have a bad RDSCONFG file, caused by an irregular termination or incorrect installation. RDSwin can’t “find itself” because that file indicates what directory has needed resource files and images. The solution is simple – exit and delete the file RDSCONFG.RTD from your RDS directory, then restart RDSwin. A new one will be created. 

RDSwin Says You have a Joystick – but You Don’t: 

This may also be caused by a bad RDSCONFG file (see above). If that doesn’t fix it, use Notepad to open file RDSwinParams.RTD in the RDSresource subdirectory. Set the parameter JoyBreakout to minus one (=-1). This tells RDSwin to skip the check to see if there is a joystick, which seems to be returning “maybe” instead of “no.” When saving the change make sure that Windows saves it in the same location as RDSwinParams.RTD and doesn’t change the extension to ( .TXT) or (.RTD.TXT). And use Notepad! Other text editors may add special characters that confuse RDSwin.

RDSwin Won’t Run, or Strange Termination Errors Occur: 

If RDSwin will not run or you get strange termination errors when saving a file or selecting a command, one possibility is that Windows has mysteriously set the attributes of some needed files to Read-Only. Go to Windows Explorer and highlight all the files in your RDSwin program directory. Right-click, select Properties, and make sure that Read-Only, Archive, and Hidden are not checked. Also do this for the RDSresource subdirectory. For good measure, delete anything in the RDStemp subdirectory.

Another way to fix this – open the command box (Start-Run) and enter C: attrib -a -r -h C:\Users\xxxx  (where C:\Users\xxxx is the full path for the folder holding your copy of RDSwin.exe). 

RDSwin is There but Not Shown Properly on the Screen

Your RDSwin screen should look something like this, although hopefully not using this horrible lime green color. The program’s window should be fully filled by the background and graphics. At the bottom you should see a row of small buttons including Exit RDS at the right. At the top you should see either an actual pulldown menu, or the “ghost menu” as shown here. To the right, RDSwin-Student should show a link for Dr. Raymer’s textbook upon which RDSwin is based. In RDSwin-Pro there should be a big button taking you to the Optimization Module.

If it doesn’t look like this, read on:

Some computer screens or resolution settings might clip off the bottom or right side of the RDSwin Window, or cause text to be too small or too large. This was especially a problem for older versions of RDSwin but sometimes happens with the latest versions too.

First try this: Go to Systems Settings, Display, and look for ‘Change the size of text,…’ Make sure that it is set at 100% (as recommended by Windows anyway). You may have to restart your computer to make it apply properly. This almost always solves the problem, if it was set to something other than 100%.

If a suggestion below doesn’t fix the problem, undo it before trying the next one. Or leave them active but write down the original settings, and try undoing them one at a time later, when you get it working properly.

Try adjusting the compatibility settings. Right-click on your RDSwin shortcut and select Troubleshoot Compatibility. Do what it says, then try restarting RDSwin. No? Right-click again and select select “Run as Administrator.” You may need to have Administrator access for this, depending upon how your computer was set up.

If still no joy, right-click on your RDSwin shortcut and try the following, in this order:  

  • Layout – Let System Position Window (normally checked already) 
  • Options – Use Legacy Console (usually this one does the trick)
  • Compatibility – Change High DPI Settings/Override high DPI scaling behavior (or something similar) 
  • Compatibility – Disable fullscreen optimizations 
  • Compatibility Mode – Compatibility for Win XP 

If it still isn’t fixed, try different values of Settings-Display-DisplayResolution. Careful – this may impact your other programs. You may want to try the method in the next section before messing with the resolution.

RDSwin is Too Large or Small within its Window, or has a Gray Border, or the Window is the Wrong Size

On some computers there are display scaling issues that result from recent changes to the information returned by certain Win-API functions. The RDSwin screen may not cover the whole window leaving unused gray areas below and to the right. The big ‘RDS’ and other text on the main screen may be wrongly sized. The program may even have trouble ‘catching’ mouse clicks on the various on-screen buttons. If the above fixes didn’t fix it, try this:  

In the main page, press hot key ‘]’ (the left-facing square bracket). This enters a secret routine for interactively changing the size of the Window itself, and the size of RDSwin within that window. Follow the instructions – carefully and slowly! When finished, results are saved so you should not have to do it again. The revised screen scaling parameters are stored in RDSResource file RDSwinParams.RTD. The original version is automatically saved as RDSwinParamsOriginal.RTD.

If you wish, you can hack those window and screen settings yourself. Go to the RDSresource subdirectory and open the file RDSwinParams.RTD using NotePad (not Word, which adds non-text characters). Find parameters ConXsizemult and ConYsizemult, and change their values to smaller numbers as appropriate. Parameter xShrinkWorld allows both width and height of the Window to be adjusted. Save the file, making sure that Windows saves it as RDSwinParams.RTD and doesn’t change the extension to ( .TXT) or (.RTD.TXT). Restart RDSwin and see how it looks. You can also experiment with parameters xScaleDrawUnits, yScaleDrawUnits, and ScaleDrawingDLM.

Hacking RDSwinParams.RTD is for experts only. You can really mess things up with the wrong values. Make sure you save an original copy before trying anything.

As you can see, that file controls a LOT of the functionality within RDSwin. Do not casually play with it!

Recovering Design Layout Module files after abnormal termination

What if you’re working in the Design Layout Module and RDSwin terminates suddenly? Good news, your most-recent design edits can be recovered. Just start RDSwin again and click on Yes when asked if you want to save the recovered file. Go to your RDSuser folder and open it, then if you wish, save it using the correct filename. If you reply No, the recovered file is immediately erased. 

I can’t see anything in a Graph or Design Layout View

Maybe you have the background and line colors set to the same color. Fix in Options-TextAndLineColors. Then laugh at yourself.

How to capture RDS graphs and drawings

RDSwin creates graphs and drawings which can be used in such Windows programs as PowerPoint(tm) and Word(tm). In the pulldown menu File options you can select SaveScreenImage (bmp or jpg), or Copy the screen image to the Windows clipboard. In Graphs or the Design Layout Module you can instantly created a bitmap image file by pressing “B”, and you can copy to the Clipboard by pressing Ctrl-C.

RDSwin won’t Print anything

It should. Make sure your default Windows printer is working properly then try again. 

RDS Units Conversion

RDSwin is fully capable in both SI Metric (MKS) units and in units of the British Imperial (FPS) type. In the FPS units RDS uses thrust in lbs., C in 1/hr, altitude in feet, and velocity in either knots or Mach Number. In the MKS units RDS uses thrust in kN, C in mg/Ns, altitude in meters, and velocity in either km/hr or Mach Number. Note that it is not necessary to identify whether knots (or km/hr) or Mach Number are used because RDS assumes that any velocity values less than 10 were given in Mach Number.

You can enter inputs in MKS or FPS, and can switch at will between them by selecting units from the OPTIONS menu. Or, you can instantly switch units by pressing `#’ (the pound sign) anytime RDS is waiting for a numerical input. 

No-Lateral-Symmetry Designs

An RDS-Professional customer known for unusual but successful designs once asked about designing aircraft with no lateral symmetry plane – including the wing. In such a design the wing may have different trapezoidal geometries for left and right side, and those sides may not even join at the aircraft “centerline” but at some arbitrary Y-location. 

To facilitate such designs, the Design Layout Module allows wings and tails to reflect across their own root chord rather than across the aircraft centerline as is the usual practice. This allows a wing or tail which is laterally symmetric but is not centered on the aircraft’s centerline.

For a truly wild design, completely different left-right wing panels can be separately created and placed. Create each separately, selecting “One Side of Global CL” when prompted for symmetry. Enter desired areas, aspect ratios, and taper ratios as if each wing panel would be reflected across the global centerline. In other words, if you are creating the left panel which is to have an area of 50 by itself, enter 100. When creating the wing panel for the right side of the aircraft, again enter double the area, but use a negative value when entering aspect ratio. This will invert that wing panel to the other side of the aircraft. You can instead use positive aspect ratio when creating the right-side wing panel then later scale it by X=-1. Another approach – create the left-side panel, copy it, scale it by X=-1, then make whatever other changes are needed.

The reason for treating these one-side wing panels as if they were part of a complete wing is simple – it allows converting from reflected to nonreflected and back again without changing the wing trapezoidal geometry. 

For weights and aerodynamics analysis you must CAREFULLY review and revise the geometric inputs estimated by the Design Layout Module in the output TAB file. It is suggested that the wing geometric inputs be defined assuming an equivalent total trapezoidal planform based on the total wing area and total span, the total exposed wing area, and an averaged sweep, taper, and thickness. 

How do I input an airfoil in the Design Layout Module?

The Design Layout Module reads airfoils in from tables. For student usage one of the stored airfoils already available should suffice for most designs. If you must use another airfoil, use WordPad to add a new airfoil to the RDS airfoil table where it will be available for use by the wing creation routine. Open file RDSAF.DAF and read the instructions. Make sure you save the table as RDSAF.DAF. Windows may try to add an extension such as RDSAF.DAF.TXT in which case RDS will still use the old version.

In the Professional version there is a point-by-point airfoil input capability which you can select instead of picking an airfoil. There is also a routine that will create NACA airfoils from a few simple inputs.

RDS-DLM acts strange when I change geometry type

The option to change Geometry Type in Component-Parameters is for experts only, and is not normally needed. It does not do any geometric conversion, it only changes the parameter that tells the drawing routines whether the stored component points represent SuperConics or are just surface points. For wings and tails, this parameter indicates the latter (=0), whereas for most other components it indicates SuperConics (=1).

If you want to convert a SuperConic component to Points, use MiscCompOptions-Convert. There is currently no capability to convert a Point component to SuperConics – you have to build it that way from the start. And, why wouldn’t you? 

I designed an airplane in MKS when I thought RDS-DLM was in FPS units (or vice-versa)

Just scale the whole thing. Select all components. Then do Component-Scale, XYZ. Enter 0.3048 if you meant to enter FPS but DLM was set to MKS, or enter 3.28084 if you meant to enter MKS but DLM was set to FPS. DLM will scale locations around the selected leader as it scales the components, so you should pick a “Leader” component with location of (0,0,0). 

Does RDSwin make drawings for me to build my design?

RDSwin does not put out drawings for fabrication. Such drawings are done on detail design CAD programs such as CATIA or SolidWorks. RDSwin does what these detail design programs cannot do – let you quickly put together an entire aircraft concept design then analyze and optimize it. When you’ve settled on an overall concept design, then you do the detail design on a different CAD program, or a drafting table if you prefer! RDSwin-Pro allows instant export of your design in the universal IGES format.

Proper use of “Design Lift Coefficient” in Aerodynamics Module

Several users have had problems due to a misunderstanding of the notion of “Design Lift Coefficient”, or CL-design in the .DAA aerodynamics input file. This is NOT the maximum lift coefficient, but the lift coefficient at which the final wing design is supposed to have its BEST L/D. Typically this is about 0.3 to 0.5, and is usually near the cruise lift coefficient for obvious reasons. The airfoil is normally selected or designed to be best at this lift coefficient as well (see fig 4.9 in Raymer’s book).

Propeller Analysis – Thrust Correction Tricks

Propeller thrust corrections are normally applied, but can be skipped as follows:

  • Tip Mach correction (Eq. 13.19) can be shut off by setting blade t/c=-1 (if set to 0, RDS assumes .03)
  • Nacelle Blockage correction (Eq. 13.18) can be shut off by setting Nacelle X-area=0
  • D/q-Cooling correction (Eq. 13.21) and D/q-Misc correction (Eq. 13.22) can both be shut off by setting Fudge-Misc=0

What are the differences between RDSwin-Pro and RDSwin-Student?

RDSRDSwin-Professional and RDSRDSwin-Student are related and are actually compiled from the same 120,000+ lines of source code. When RDSwin-Student is compiled, many features are skipped by a compiler meta-command, which also makes certain changes that reduce the accuracy of results. An important difference is the license agreement. RDSwin-Student is licensed only for student use, and is priced accordingly. More information and a comparison between RDSwin-Pro and RDSwin-Student can be found here. 

Raymer’s Secret RDSwin Hacks

As we all learned from the classic movie Wargames (“…shall we play a game?…”), we computer programmers cannot resist the urge to install “backdoors” and other hidden code. I’ll reveal a few, as I feel like it, starting with:

  • Click Help>About RDSwin. Click it several times. Look to the bottom for pithy sayings. But they don’t always appear – keep trying.
  • Entering the exclamation mark ! from almost any menu or prompt will immediately terminate RDSwin. All work is lost except recent edits to your design layout (DLM), so be careful with this! 
  • In any Design Layout Module View, pressing the Underscore _ (looks like a slicer) will render that design, but slowly. You’ll see it start from the farthest away point, drawing every panel of the display as it moves forward, including all internal components. Pressing the backslash \ allows you to take a slice through the current view, with location defined as percent of display depth into the screen. Fun, but not very useful. 
  • In the Design Layout Module, press * to calculate and show the equivalent NURB/Bezier middle point in Shape One Cross-Section. You cannot grab and move it, since RDS uses different mathematics in which the middle point is actually on the curve. This secret hack lets you see how lucky we are, that this is the case. 
  • In the Design Layout Module, the number keys 1-0 define various canned views. Pressing `, to the left of 1, gives a Front View. This looks like a Rear View until you Render (R). Pressing -, to the right of 0, gives a nice 2-view where the side and top views are larger and more visible than in the 3-view made by pressing 6. 
  • In the Design Layout Module, press [ to toggle a listing of the current view’s roll-pitch-yaw, pressing [ again adds the coordinate transformation matrix, then again adds the scale factors used to create the display on screen. For CAD coding geeks only. Note that [ looks like a matrix bracket.
  • Make sure your speaker is on, then double-click on the big RDS on the main menu page. Try it several times.
  • When displaying inputs or results using the RDS Console (List&Print-DisplayOnRDSConsole), you normally toggle through the available color schemes by pressing C until you see colors that you like. Instead, try the secret hot keys, namely the letters J (Jamaica), G (Germany), A (America), I (Irish), V (Viking), W (white&black), and B (blueprint). Pressing the same secret key a second time will return to the previous scheme.

RDSwin Bug Alerts

Bugs, Mr. Rico. Zillions of em!

(at present, no bugs are known in V14. But the day is young. All bugs in previous versions have been fixed in V14.)

Not a Bug, but: If you download a Selig airfoil from http://airfoiltools.com, the file will sometimes have a LineFeed rather than a CarriageReturn at the end of lines. You need to fix those before asking RDSwin to read it while creating a wing or tail. Try the ReplaceAll button in Notepad++ with Search Mode set to “Extended” and change LF to CR. Another option is to Open the file in Excel using Delimited>Space, then save it as a TXT file. Clumsy, but it works!  

Please send Bug messages to AircraftDesign.Com . Be clear, be specific, and be nice! 

Old Dead Bugs

BUG ALERT 1: The ShapeComponent problem is fixed for versions after V6.3. 
BUG ALERT 2: The Quick Initial Sizing routine bug is fixed for versions after V6.3. 
BUG ALERT 3: The problem with titles for the input grids for uninstalled turboprop engine data is fixed for versions after V7.0.
BUG ALERT 4: Problems with various metric inputs/outputs is fixed for versions after V7.1. 
BUG ALERT 5: The old flight control weight calculation error for cargo/transport airplanes is fixed for versions after Version7.1.
BUG ALERT 6: See above for a new routine to fix Window scaling issues.
BUG ALERT 7: The DLM Insert Circle routine asks for Radius but treats the input number as Diameter. Fixed in V10.
BUG ALERT 8: Strange behaviors for components listed after an imported STL component. Fixed in RDSwin-Pro V10.3.

Where are the old RDS-DOS Tips and Tricks?

Still running RDS-DOS? You might be the last one. Call a museum. Then get RDSwin just as soon as possible. But if you are looking for the old RDS-DOS tips and tricks, click here.