PROP_DESIGN and related files are available at the following locations:


Microsoft OneDrive:

Google Drive, alternate location, if having problems downloading from above:

All files I have uploaded are virus, spyware, and malware free. However, it is a good idea to scan all files you download, to ensure they haven't been tampered with.


Most recent changes:

  1. Updated the Fortran Compiler Comparison. Compared mingw-builds 7.1 to Intel Parallel Studio XE 2017 Update 2 using PROP_DESIGN_MAPS. Deleted all benchmarking versions of PROP_DESIGN. The Fortran Compiler Comparison will be done using PROP_DESIGN_MAPS from now on. Moved the Fortran Compiler Comparison folder to the root folder. The benchmarks I used are in the BENCHMARKS sub folder. The only difference between the PROP_DESIGN_MAPS and BENCHMARKS folders is the addition of numerous *.bat files (which are used to conduct the benchmarks). Updated the user manual and website as well.
  2. I have been noticing more and more websites using an old version of PROP_DESIGN, called MP_PROP_DESIGN, to show how Fortran auto-parallelization benefits it. I have never been able to duplicate these results. I have tried numerous times to get the website's claiming such benefits to back it up and use the current version of MP_PROP_DESIGN, which is PROP_DESIGN_MAPS. They refuse to do either thing. As far as I can tell, auto-parallelization from any Fortran provider is a completely useless feature. Disregard any benchmark utilizing  MP_PROP_DESIGN. They should be using PROP_DESIGN_MAPS or nothing at all, wrt PROP_DESIGN benchmarking.
  3. Added alternative download location. Based on web traffic, it seems like some people were having problems downloading from Microsoft OneDrive. I can't duplicate any download problems, however, I'm adding Google Drive as an alternative location. Download issues could be caused by certain internet browsers, antivirus software, hosting providers, etc... Your government may have firewalls blocking downloads as well.
  4. On 09-26-17 published on this website a very cool, useful, and unique flying wing concept of my own design.
  5. A new example is coming soon. I take a look at modern turbofans and find some interesting things.

Unfortunately, there is no change log. I started developing PROP_DESIGN in 2008. There have been so many changes over that time, that the change log would be huge. I always recommend using the latest version of PROP_DESIGN. Description of the PROP_DESIGN download follows.


Documentation Folder:

  • The PROP_DESIGN User Manual folder - Contains the PROP_DESIGN User Manual, applicable to the 64-bit Windows version of PROP_DESIGN (as the other versions of PROP_DESIGN did not exist at the time the document was written). I recommend reading the PROP_DESIGN User Manual, even if you are not going to use the 64-bit Windows version of PROP_DESIGN. This is due to the fact that all versions of PROP_DESIGN are very similar. Moreover, once you understand how the 64-bit Windows version of PROP_DESIGN works, you can easily figure out how the other versions function.
  • The Reference Information folder - Contains information which, among other things, aids the understanding of the PROP_DESIGN source code, derives some important equations, and answers some common questions.

Fortran Compiler Comparison Folder:

  • BENCHMARKS folder - Based on PROP_DESIGN_MAPS. The only difference is the addition of numerous *.bat files. The *.bat files are what is responsible for actually running the benchmarks.

Optional Documentation Folder:

  • The Airfoil Model folder - Contains information regarding the airfoil model utilized by PROP_DESIGN.
  • The Atmospheric Model folder - Contains information regarding the atmospheric model utilized by PROP_DESIGN.
  • The Stall Model folder - Contains information regarding the stall model utilized by PROP_DESIGN.

Optional Programs for 64-bit Windows Folder:

  • The AIRFOIL_CFD_INPUTS folder - Contains a Fortran 77 program that helps correlate airfoil wind tunnel data to CFD inputs. You input airfoil chord, Reynolds number, and Mach number. Geopotential altitude, density, speed of sound, kinematic viscosity, pressure, and temperature are output. This is useful when the chord analyzed by CFD is different than what was tested in the wind tunnel. This causes the atmospheric properties to change.
  • The ATMOSPHERIC_PROPERTIES folder - Contains a Fortran 77 program that will output various atmospheric properties. It uses the same atmospheric model as PROP_DESIGN. You input geopotential altitude in units of feet. Density, speed of sound, and kinematic viscosity are output.
  • The ATMOSPHERIC_PROPERTIES_ALT folder - Contains a Fortran 77 program that will output various atmospheric properties. It extends the atmospheric model used by PROP_DESIGN. You input geopotential altitude in units of feet. Density, speed of sound, kinematic viscosity, pressure, and temperature are output.
  • The VELOCITY_CONVERSION folder - Contains a Fortran 77 program that will convert true airspeed to Mach number. Moreover; true airspeed (TAS) in units of mph, combined with geopotential altitude in units of feet, are used to determine aircraft velocity in units of Mach (which is an input to PROP_DESIGN).

PROP_DESIGN 64-bit Windows Folder:

  • The PROP_DESIGN folder - Contains various versions of PROP_DESIGN. Each version of PROP_DESIGN contains examples. The best way to get started with PROP_DESIGN is to review the PROP_DESIGN User Manual and run the examples. If you are interested in aircraft propeller theory, study the PROP_DESIGN source code files and reference information.
  • The PROP_DESIGN_UNDOCUMENTED folder - Contains undocumented versions of PROP_DESIGN. They were created to study different aspects of PROP_DESIGN and aircraft propeller design in general. One particularly useful version, creates performance maps for constant speed propellers. Although these versions are undocumented, if you are familiar with PROP_DESIGN, you will have no trouble figuring out how to utilize them. Since I am finished developing PROP_DESIGN, I decided to share them with you, rather than just delete them.

Download Notes:

PROP_DESIGN was first released on March 12, 2010. Please use the current version of PROP_DESIGN, as it contains many bug fixes and new features.


All versions of PROP_DESIGN have been tested on AMD and Intel x86 processors. However, they should work on any processor capable of performing 64-bit floating-point arithmetic. You would have to re-compile the source code files to experiment with other processor types.

32-bit Windows:

If you need to run PROP_DESIGN on 32-bit Windows, you will have to re-compile the Fortran 77 source code files. I recommend using the Intel Fortran compiler, in order to achieve the highest performance. If you would rather use gfortran, MinGW-builds is a good option.


In November of 2012, I tested PROP_DESIGN on Linux. PROP_DESIGN works fine on Linux, as expected. For use with Linux, place the 64-bit Windows versions of PROP_DESIGN in your Documents folder. Delete all *.bat and *.exe files. You will need to install gfortran and gnuplot. Make sure the wxt terminal is the default for gnuplot. Lastly, re-compile all source code files, using gfortran.


In January of 2014, I tested PROP_DESIGN on an Android tablet using three free apps. I was able to compile and run PROP_DESIGN using CCTools and the 920 Text Editor. I was able to view all *.plt files using the Mobile Gnuplot Viewer (free) app. These apps require a fair amount of free disk space to install.


You may have to edit all of the *.plt files. Moreover, the paths to the *.dat files need to match the locations of the files on your particular device. This seems to be a limitation of the Mobile Gnuplot Viewer (free) app.


The Android tablet used a 32-bit ARMv7 processor. There were no issues compiling or running PROP_DESIGN. Comparing results, obtained with the 32-bit ARMv7 processor against those from a 64-bit x86 processor, showed agreement down to the last significant digit.


During Android testing, I did have one issue. CCTools froze, while installing the Fortran add-on. I rebooted the tablet and re-opened CCTools. The Fortran add-on showed as installed. However, once I went to use it, it wasn't actually installed. So I uninstalled the Fortran add-on and re-installed it. There were no issues during or after the second install.