In this site there is a java freeware about designing an aircraft and lots of useful links and free software to download in relation with experimental aircraft ; experimental engines builders ; advanced technologies and space flight links There is also some explanation on the basic working of engine and videos of open and working engines .

To see the site content click here content the site content will be displayed on the side bar .

updated june 2 2005

The star quotation :

This is an item that is above the average in interest for the considered information

or "good" This is an item that is very interesting to see for the considered information...

or "very good " This is an absolute must see for the considered information...




The recent additions :

The tag is for a recent addition to the site (few month)

For actual recent additions on display search the tag within this page

xcor is a company that produce reliable small lox rocket engines (project section)

a complement to the uiuc airfoil database (airplane designer)

succesful flight of a Supersonic Combustion RAM jet at M 8

home built pulse jet and ramjet engine (hobie model) (home pages)

some one in france asked me if I could build a standard atmosphere computer ...(freeware download)

universal overcraft a company that produce hovercraft able to fly in ground effect over obstacles (seem realy impressive)




Mandatory Ground & Elevator Inspection

In light of a recent fatal accident Rutan Aircraft Factory has called for a Mandatory Ground urging all builders and canard pilots to inspect their elevators for correct shape, size and balance. While the NTSB investigation is not complete, it appears that the elevator was incorrectly shaped and counterweighted resulting in separation. The elevator is the most important part of any aircraft and should be built to exact specifications. Here is the downloadable documentation for more information : mangndelevators.pdf

The following inspection is required before next flight. While it is true that RAF cannot issue an AD, we are requesting, in the strongest possible way, that all owners of Varieze and Long-EZ aircraft comply with this inspection before you fly again. (quoting from the company)

If there is another aircraft out there somewhere that is built like the one recently involved in an accident, it will probably kill someone. Please help us to locate it and save a life. (quoting from the company)

Also important check this one








this is a utility that help the homebuilder to make Some tricky computation in order to help defining the project of building an airplane. You must define the mission target and the software will Tell you the compromise to do and after the choice have been made the preliminary data will be computed


actual mail address is

alexander voivoditch

43 bd vincent delpuech

13006 marseille


E mail address :





This utility let you define the mission target :

And the limiting factors at the values that you know you can reach as an aircraft builder :

Then the resulting data will be returned . Here are the returned data :

If one or more of the data is out of specification you know that you must gain on some of the limiting factor or in last resort that you must re evaluate some of the mission target and compute again . By cycling through this iteration process you will come closer and closer of your goals . Tis is the FIRST ESTIMATION phase

After the estimation phase is finished using the computed set of data you can go trough the other tools such as vertical speeds computer ; material resistance computer ; takeoff distance computer ; wing angle set computer ; tail volume computer ; and yet to come : tail angle set computer ; and more tools

there are also some tools such as

the spar flex under load computer , airfoil modificator and browser (browse in a local copy of the UIUC airfoil database) that are already functional and more are to come .

.this is a freeware but any contribution would be very welcomed any other use than private or school requires to be in contact with the author


I may also develop on demand some small tools for very little money or even free it all depend of the time passed and the usefulness to other people . (see the isa computer applet under)

This utility need a display capable of 1024 X 768 and 256 colors resolution minimum and a computer capable of running java JRE v 1.3.1 (most pc win 95 computer can do that even the old one). The mac will need java MRJ 2.2.5, ( it must be a Mac OS 8.1 or later)the mac with os X is already ready for java

This site is a work in progress. I am working to improve and expand it. All comments are welcome. If you have suggestions on how to improve this site please contact me. For info on this site or suggestions please e-mail: (this is NOT the same address as the site )

download file or use applet :

Some one in france asked me if I could build a standard atmosphere computer so here it is :it take in input the altitude and the difference of temperature between standard and actual temperature ;then it will return the temperature specified at that altitude and the mass per volume of the atmosphere (slug per ft3) or in metric units (kilograms per m3) at that altitude and temperature . It is valid all the way up to 65617 ft (20000m) It can be extended much higher ... It also require the java vm !

isa_computer_applet (it may take 30 sec to load )

here is the java executable version available to download java_exec.ZIP

to download the performance_computer V2.1 follow the link : base.ZIP :

current release january 27 2002 better user interface ; more tools user friendly it will install over any existing issue the install is the same as the old versionfollow the above link. just erase the old one and put the new one on place . If you want to save the old work you can keep the old airplane text file in an other directory. There is also a Beta release V2.2 available

this is a Java executable you need the Java virtual machine in your computer no matter if it is a PC apple sun or something else . If you do not have it , then you need to download the appropriate virtual machine it will work on most operating system available : unix ; linux ; windows ; mac os ; etc

For a pc computer with windows 95 TM or more there is theJRE v 1.3.1 ; The Java Runtime Environment, (JRE) consists of the Java virtual machine, the Java platform core classes, and supporting files. it is an auto install just click it , that's all to it!

The JRE is packaged with the Java TM Plug-in software that enables widely-deployed web browsers to use the Java 2 Runtime Environment to run applets.

The download size of the file j2re-1_3_1-win.exe is 5,364,696 bytes. it takes about 20minutes with a 33600 modem to download it is an exe that will automatically install the JRE v 1.3.1 on your computer

to download the JRE v 1.3.1 follow the link : :

For an apple computer with the Mac OS X Java is fully supported !

For an apple computer with an older os (Mac OS 8.1 or later) in order to run the utility you need the MRJ 2.2.5, It is Apple's implementation of the Java Virtual Machine (JVM), based on Sun microsystems' Java 1.1.8 specification. You need a minimum of 64 MB RAM ; a Macintosh computer with a PowerPC processor ; and a Mac OS 8.1 or later with at least 13 MB of free disk space

to download the MRJ 2.2.5 follow the link :

To run This utility you need MRJ 2.2.5, or an mrj that is JDK 1.2.1 compliant if MRJ 2.2.5 is not compatible with your os you might try one of those i am far from using all the feature of the MRJ 2.2.5 however result is not guarantied I have not tried it ! let me know if it work

Here are some MRJ'S and JDK compliance and corresponding supported os :

MRJ 2.2 JDK 1.1.7-compliant Mac OS 8.1 and later, PowerPC, 32 MB Free RAM, 20 MB Free Disk space
MRJ 2.1.4 JDK 1.1.7-compliant Mac OS 7.6.1 and later, PowerPC, 32 MB Free RAM, 20 MB Free Disk space
MRJ 2.1.3 JDK 1.1.7-compliant Mac OS 7.6.1 and later, PowerPC, 32 MB Free RAM, 20 MB Free Disk space
MRJ 2.1.2 JDK 1.1.7-compliant Mac OS 7.6.1 and later, PowerPC, 32 MB Free RAM, 20 MB Free Disk space
MRJ 2.1.1 JDK 1.1.7-compliant Mac OS 7.6.1 and later, PowerPC, 32 MB Free RAM, 20 MB Free Disk space
MRJ 2.0 JDK 1.1.3-compliant Mac OS 8.0 and later , PowerPC/68040, 8 MB Free RAM, 30 MB Free Disk space
MRJ 2.0 JDK 1.1.3-compliant Mac OS 7.6.1 by custom install , PowerPC/68040, 8 MB Free RAM, 30 MB Free Disk space
MRJ 1.5.1 JDK 1.0.2-compliant Mac OS 7.5 and later, PowerPC/68030/68040, 16 MB Free RAM, 7 MB Free Disk space

Beta release February 28 2002 better user interface ; new airfoil editor . more on the end of the file : freeware historic .

It will install over any existing issue the install is the same as the currant version follow the download link under . just erase or move the old version to an other directory and put the new one on place . If you want to save the old work you can keep the old airplane text file and dtx files in an other directory and bring them back in the new directory when finished with the install. The beta release is compatible with the current release file format . It is supplied with 1100 airfoils (directory foils)data from the uiuc under gnu public licence please have a look at the term of the gnu public licence in the directory (modified_airfoil) are some modified examples airfoils .

to download the Beta release V2.2 follow the link : :

here is an example of modified files with the beta file : global 120% y scale ; original ; and modified vertex. (moved vertex in order to add thickness in the 1 st third of the chord) using the soft you can superimpose the three foil diagram to check the changes. (load 1 st dat file then click compute draw ; load 2 nd dat file then click compute draw ; load 3 rd dat file then click compute draw . do not click refresh graph)

here are the files : modified.ZIP in order to view them with the beta extract the files in the directory modified_airfoil



To install just create in the drive c: the folder airplane and then into the folder airplanethe sub-folder myhomebuilt and extract the ZIP files into it. Now with the program manager locate the file aero.bat in the subdirectory myhomebuilt. And then you can slip it (right click the file aero.bat) from the program manager on to an open space of the desk (create a shortcut) this way you will have an icon to start (with windows)... easy to use !


However Here is the point bat start file structure you can change the structure of this start file to suits your needs .


set classpath=%classpath%;yourdrive:\yourfolder\yoursubfolder\preliminarydraft.jar

cd yourdrive:\yourfolder\yoursubfolder

java performance_computer

here is the way to do it :

This is very important that you do not change a thing except the words in red . Do not add space where there are not . The only spaces are between the word set AND classpath and between cd AND yourdrive you can add sub levels into your folder . Do not mix up between the ; and the : The example is available at download (aero.bat) or into the downloaded zip file ; that way you can modify it to suits your needs . Slip (right click) this file from the program manager on to an open space of the desk(create a shortcut) this way you will have an icon easy to use . When done right click on the newly created icon and select edit in the popup menu. You can change the word (name of the file) aero for what ever you want but you must keep the end (.bat) :aero.bat this is very important .

Warning this is case sensitive . You can add or delete some sub level if needed .



set classpath=%classpath%;c:\airplane\myhomebuilt\preliminarydraft.jar

cd c:\airplane\myhomebuilt

java performance_computer



set classpath=%classpath%;f:\cad\soft\homebuilt\preliminarydraft.jar

cd f:\cad\soft\homebuilt

java performance_computer



set classpath=%classpath%;c:\design\preliminarydraft.jar

cd c:\design

java performance_computer

The following are links to some aviation web sites that may be helpful for homebuilder and pilot.

.official web sites. Aircraft Owner and Pilot Association Experimental Aircraft Association homebuilt magazine Federal Aviation Administration Federal Aviation Administration (aircraft certification) The Aviation Digital Data Service is used by military and airline to gather information about the weather a real good one

.interesting web sites.

very good homebuilt site

very good homebuilt site

very good engine directory

very good aviation info's site with huge possibility to stay informed (by newsletter mail) lots of interesting links this is definitively a must see (free)

good experimental aircraft database but a bit tricky to use : you need to type exactly the name of what you are searching for example varieze do not work but vari eze will work partial designers/vendors names are ok rutan without burt work . It seems to be not case sensitive

electronic homebuilt for homebuilt

. kits ; parts ; plans ; Tools ; software.


A very nice four seat canard pusher , easy to build and fly


very nice tandem2 seater jet kit fighter like ,specs .performance is at the core of the design concept !!! "the Viperjet tmis the only kit plane in its class, with a sleek fighter look and a jet powerplant. We're sure it will meet and exceed your need for speed, agility and bragging rights ; high cruise speeds, low stall speeds and full aerobatics capabilities.Top speed at 25,000 feet 360 or 320 knots depending on engine choice" total cost of ViperJet Kit: $134,900(for the first 10 orders) (quoting from the company)


very nice tandem2 seater jet kit fighter like. Born of company president George Bye's intense desire to bring military style and performance into the general aviation arena, Aviation Technology Group, Inc. is leading the way in the design and development of cost effective, high performance jet aircraft.(quoting from the company)

very nice composite kit. This is the first premolded composite kit aircraft ever offered! .
the Glasair III turbo goes up to 272 kts at 24 000 fts and the glastar is a highly versatile airplane,
both easy to build(quoting from the company)

universal overcraft a company that produce hovercraft able to fly in ground effect over obstacles (seem realy impressive)

there is a video on the site that can be downloaded it realy deserve a look


"If you fly, repair, restore or build aircraft you need our catalog. Fully illustrated with over 30,000 products for certified, experimental and ultralight aircraft and the pilots that fly them. " (quoting from the company)

indeed a very good free catalog !

This is a conversion kit to ANR for common headset an interesting project !

Innodyn is a company that offers a number of Turbines to meet the experimental pilot's needs, they range from165 Horsepower and $26,500 to 255 Horsepower and $34,500 there are some interesting video on the site

plan built

A good site about the rutan canard pusher varieze ; long eze ....


Very good tools . If you repair, restore or build an aircraft you need those high quality tools . they will save you invaluable time and may also save your work (ever ruined a thread with a bad tool ?) certified mechanics use them . You must have a look at the catalogue because they have tools that you may not even knows of the existence , and that will dramatically ease the job.

their home page

one of their catalogue that may be useful

Very good tools . If you are living in europe they are the number one in europe . Those high quality tools have a life warranty for normal use if the tool fail they will give a new one for free . I did personally tried that : in a remote field emergency i had to use a one yard long lever on a ratchet wrench (definitively not a normal use!), it did the job but got damaged in the process . However the guys at facom have been kind enough to give us a new one despite the (evident abuse) of the tool .

their home page english (uk) orfrench


a very good flight planer with a free demo it does not eat'up your disk space .

Panel Planner 2.8 is a software that permit to save time designing the instrument panel there is a demo on on line try using the zoom option to make it work the right way

Mprofil : this is a very small utility in german that permit to precisely print airfoils in order to cut airfoils for the wings of a validation model it is so easy to use that there is no need to speak german locale copy mprofilzip.exe

This introduction is written for pilots (and others) who are interested in great circle navigation and would like to know how to compute courses, headings and other quantities of interest. These formulae can be programmed into your calculator or spreadsheet. there is also a very interesting spreadsheet example and good programming advice

Internet site The Aviation Digital Data Service is used by military and airline to gather information about the weather a real good source of info's

more to be added here later

.interesting web sites for the airplane designer.

very good engine directory where you can find size and weight of engine

Very goodaerodynamics site this is very useful for someone that is willing to know what airfoil is present on most of factory made airplane or localcopy if not working: airplane_airfoils.doc

Very goodaerodynamics site this one list lot of airfoils that ar not on the uiuc site (above) this one should also be uefull for the hobie modeller (model specific airfoils) it is available in english spanish and french

Thissite permit to pickup the data of the airfoil selected in the above above or localcopy if not working:

XFOIL 6.91 and later (from Prof Mark Drela, MIT) , this one is somewhat the complement of the previous one in the way that when you get to know the airfoil you are going to study then you can make a complete study of it through this free software . However be warned this is a though one to use , but lot of help is available . It is not one of those toys nice to see easy to use but not really useful this one is a tool and you need to spend some days to learn to use it but it is really worth the effort if you want to study an airfoil it also work very well at low reynolds number it is used by hobby scale modelers

Panel Method for Windows from Thomas G. Rudowsky and Karl W. Mortara (Pennsylvania State University) Itis a free low-order panel method developed to run under Microsoft Windows 95. It includes aerodynamic force calculation based on the hybrid method developed by Mortara and Maughmer or pressure integration, a wake relaxation scheme, a chord optimization method to generate optimal lift distributions, as well as an easy to use interface and graphical displays. (quoting from the help file) This one is easy to use and interesting

.raytracer and modeller (making a picture of your project)

Those two goes together the first one (POV) permit to build a scene of your project through a text editor while the second one (Moray V 3.3) permit to easily build the needed text file (actually a pov file) trough an interactive wire-frame modeller . Here is an example of what can be done . strike (two pictures svga size)

Persistence Of Vision for Windows POV for Windows and other platforms . It is a free raytracer ( a tool for producing high-quality computer graphics ) this one creates three-dimensional, photo-realistic images using a rendering technique called ray-tracing it can be used to make a picture of the future project and check the look of it. It is one of the best ray tracer i have ever seen and it is free

Moray V 3.3 is an interactive wire-frame modeller that allows you to model a world for POV-Ray interactively, allowing you to see the setup of your scene as you build it. No editing of POV-Ray script files (unless you really want to). Moray displays a wireframe representation of the scene in 2D views and 3D camera views . It is a shareware it is not limited in any way .

Epanel builder is an on line freeware that permit to see the future instrument panel. You can choosemove and place your instruments and most instruments are also linked to the factory . Important note : this site work only with internet explorer5 or more it is a good site with a lot of instruments and is really user friendly :

.entertainmentweb sites.

the one hundred dollar hamburger :

Unusual Aviation Pictures ;-)

Huge collection of very nice Aviation Pictures, this site requires the use of the back button of your browser

Movies and pictures from Boeing

.some home pages of interest.

home built engines

homebuilt jets engines , some of them are non flying hobby unit based on truck or car turbo conversion but it is still worth to see some very good job from other people jets

the gas turbine builders association The Aims of the Association: To encourage and support the safe design and operation of small gas turbines, either as stand alone units or for the purpose of powering model vehicles. This is very interesting to see ; plus a lot of links

home built pulse jets and ramjet engines This site is about building home build pulse jet ; ram jet and turbine engine for hobie model . Note that this activity (pulse jet) is regulated in some country because of the very high risk of forest fire should the model be lost (may be dificult to reach at this time)

A downloadable xls file for those interested by building pusejet model is available in the site above it realy deserve a good look it is good and easy to use

.some nice project homebuilt or not.

"xcor" is a company that produce reliable lox rocket engine from 50 to 400 lbs trust they tried it on a long eze a flight to over 9000 ft altitude ! those engines are (hard start free) due to a special igniter the company developed . They are also building a new pump adapted for in flight relight and small rocket propellant flow .

the "beriev" company produce the some best anphib in the world these are rugged , reliant aircraft The main site is russian or english There is an amazing anphib twin engine plus some other airplanes

The star of the company is the BE 200 a smaller derivative of the famous albatross this is a jet airplane airliner sized anphib !!. There is a video on line that is quite big to download (60 mb) this site and the video are in english !

.some interesting sites for future SPACE flight and advanced technologies

.Molecular Magnetism and Levitation small pilot acceleration compensation ;-)



(the next step in solar system exploration)

This engine is very interesting for the coming mars missions already tested with success the name is: Variable Specific Impulse Magnetoplasma Rocket . it does present lots of advantages such as Variable Specific Impulse and Thrust at maximum power ; High power density; Capability for powered mission aborts ; compatible with high payload robotic cargo missions as well as fast, lower payload human transfers permit to leave planetary orbit faster and remain efficient during transfer . high reliability ..

space electric propulsion

it appears that the DeepSpace probe succeeded in it's final bonus mission it took good pictures and infrared data of comet borrelly nuclei . It was launched in 1998 it's primary objective was to test ionic propulsion ... this little probe did much more than that !

plasma resources on internet


Thermodynamics Research Laboratory ; Data and Property Calculation Sites on the Web

Mechanism analysis links ( combustion chemistry )

russian site about the russian hypersonic project ajax this project would use cracked fuel with water or H2.O2. and would also make use of magneto hydrodynamic energy (MHD energy bypass) (converting kinetic energie of incoming plasma to electricity and re injecting this electricity in mhd acceleration at engine nozzle to re distribute it where needed) it would also use MHD for active control of attitude and in order to actively shape the shock wave . The fact of doing that combined with endothermic fuel cracking will partiallyshield the hull from friction and compression heat . Combustion in partial plasma phase would also be controlled by mhd

and an other one

The us X34 engine (fastrac) may also use endothermic fuel cracking

succesful flight of a Supersonic Combustion RAM jet at M 8

land based engine and interesting laser

interesting femtoseconde class laser and interesting observation on natural beam collimation in air and wavelength shift

good database on rocket user friendly and lot of of info's ; by name ; by program ; or by year . (seems inactive at this time)

.Important Technology to develop for future flight






: performance_computer V2.1

or study the preliminary datas of a project

visitors since sept. 01 2001

Here are some of the characteristics to enhance in order to reach the assigned goal

design goal characteristics to enhance comment
high payload
  • power
  • low empty weight
  • low empty / gross weight ratio
  • here the critical item is the empty / gross weight ratio
  • high power will help
  • high lift coefficient
high speed
  • low drag
  • low flat plate equivalent
  • small wings (cruise drag)
  • high power
  • structural stiffness
  • thin airfoil (supersonic)
  • supercritic airfoil (high subsonic)
  • drag is in proportion of the cube of the speed the flat plate equivalentshould be kept minimal
  • high power or trust will be a must
  • above 300 kt jet is a better power source
  • a serious aeroelasticity study is a must
  • subsonic airplanes will be limited by compressibilty effect ; shockwave induced airflow separation ; drag rise for thick airfoil (here supercritic airfoil are useful delaying shock separation)
  • supersonic jet will be limited by compression heat both within the engines and structure (SR71)
low speed
  • large wing area
  • high lift airfoil
  • high lift devices
  • low weight
  • the lift coefficient should be kept the highest possible
  • increasing wing area will help also
  • low weight is an advantage because the lesser the wing have to work the lesser will be the needed wing area and lift coeff
short takeoff

and landing (stol)

  • large wing area
  • high lift airfoil
  • high lift devices
  • low weight
  • high power
  • here requirements are the same as for low speed
  • but high power is critical to shorten the acceleration
  • high lift devices are very helpful here giving a high lift coefficient at takeoff and landing and giving a better wing for higher speed operation at cruise
high climb rate
  • high power
  • low weight
  • low drag
  • the climb rate is the excess power available relative to what is needed for maintening horizontalflight
  • so high power conjuged with low drag and weight in the same flight conditions is a must
long range
  • low drag
  • low weight
  • low fuel burn(high fuel efficiency)
  • high fuel capacity
  • long span
  • high fuel weight ratio
  • the flat plate equivalentshould be kept minimal
  • long span because best range occurs at low speed were induced drag become important
  • low weight ; low weight is an advantage because the wing will produce less work and so less induced drag to overcome by the engine
  • good fuel efficiency is of primary importance
  • of course high fuel capacity is mandatory
  • good use of altitude adaptation and speed by the pilot
high ceiling
  • high power
  • high altitude engine (turbo)
  • low weight
  • low drag
  • long span (subsonic)
  • need high altitude engines, here the turbos will truly shine
  • subsonic jet will be limited by the convergence of the rising minimum flight speed and the maximum mach
  • supersonic jet will be limited by compression heat both within the engines and structure (SR71) or high speed instability
  • long span can help for subsonic operations because the flight may be close to minimum flight speed (induced drag) (U2)

here is help on some concepts that may not be obvious in the first time and some unusual facts

reciprocating engine basic take 40 seconds with a 33 600 kbits/s modem

radial engine layout basic take 20 seconds with a 33 600 kbits/s modem

turbofan engine layout basic take 40 seconds with a 33 600 kbits/s modem

shareware command help

Payload m 170 lb. f 150 lb.

the payload is the weight to be carried by the airplane 170 lb. for men and 150 for woman seems to be a good starting point for crew and passenger weight estimation (these are the weight the faa use for estimation ). Think also to allows Some weight for cargo . The fuel is not included here because it will be computed and returned : (payload + computed full fuel+computed empty weight = gross weight).

Empty / gross wt ratio 0. 54 to 0.62

This is the ratio of the empty weight on gross weight it is determined by the technology used for the building :empty weight ( no pilot no passengers no cargo and no fuel weight ) divided by the gross weight for light aircraft this ratio range from 0.54 to 0.62

fuel weight ratio

This is the fuel weight divided by the gross weight

for light aircraft this ratio range from 0.11 to 0.17

for medium turboprop aircraft this ratio is around 0.2

for large airliner aircraft this ratio is around 0.4

aspect ratio

This is the ratio of the span divided by the chord length it is an important factor in aircraft design for performance ; it also have an impact on weight and structural stiffness .

For light aircraft the aspect ratio is around 6 to 8 it can goes up to 12 for Some light twin (here the engine weight is not supported by the wing root) and much more for motor glider it can goes down to 2 for some deltas wings and even less for some lifting bodies

Cl max.

This is the maximum lift coefficient a wing can achieve

With no flaps most of the time for a common thick light aircraft wing this is around 1.3

With plain flaps this is around 2.1

With split flaps this is around 2.4

With slotted flaps this is around 2.6

With fowler flaps this is around 3.0

the fowler flaps also increase the wing area , they are oftenly found with leading edge slats .the combinaison of both is present on nearly all airliner and some S.T.O.L. aircraft such as the aerospatiale rally (french airplane fitted with automatic slats and fowler flaps (very efficient)) . The slats increase the maximum angle of attack when the flaps do the contrary so a combination of both is optimum . Both of them increase the maximum lift coefficient

STOL = Short Take Off and Landing

Cruise speed

The cruise speed for this application is given in knots true airspeed with no wind and the same is true with all the speeds of the application

Equivalent flat plate

This is the area of a virtual plate that would have a drag coefficient of 1 and whose area would be the area needed to produce exactly the same drag as the drag of the plane in the same conditions . To compute it you can do it this way :

the wetted area of the airplane times the number of drag counts

very clean composite airplanewith laminar foil goes around 0.0045 drag counts /sq fts

factory metal airplane with round rivets are around 0.0065 drag counts /sq fts

the result is the flat plate area , this is of the greatest influence on the airplane performance so keep conservative on this item , check other looking like design ; knowing what are the performances and design of those airplanes you can deduce theirs flat plate area using the software . this is important to train this way in order to get a good feeling on what can be done with the shareware

here are some examples they are aproximative

Wetted area Flat plate equivalent area
Varieze 247.5
Cessna 152 6.14 Piper tomahawk 6.64
Long ez 325 Beech skipper 6.36
Solitaire 297.3 Cessna 172 6.25
Variviggen 458.2 Piper warrior 5.83
Catbird 398.8 Beech sierra 5.02
Quickie 190.5 Mooney 201 2.81
Swift 460.8 Piper arrow 4.64
Defiant 517.8 Cessna 182 5.27
Voyager 1337.7 Beech bonanza 3.47
Pond racer 478
Glasair II 329.1
GlasairIII 360.6
Cirrus 565.5
Questair venture 280
Lancair 320 325
Beech bonanza 668
Cessna 172 675
Cherockee 4 place 601

Standard wing loading correction factor

The standard wing loading correction factor is a number that permit the computer to deviate from the common wing loading for the aircraft size considered . For example a S.T.O.L.( short takeoff and landing) aircraft such as the husky A-1A have a lower wing loading than usual in that aircraft size : coefficient of (1.12) instead of 1 .

The software will automatically increase the wing loading with the airplane weight but using that coefficient it is possible to force higher or lower wing loading than used in common cruise airplane . This is used for S.T.O.L. aircraft ; fast cruise or stiff aerobatics .

The flight envelope

This is the diagram that represent the limitation of the airplane

Saving the files

Opening the files

Deleting the files

The file information window

The file information window makeit possible to write in plain language a few comment on the current project . It is also saved with the other files

The airfoil design

the airfoil design menu permit to edit and modify airfoil in order to pass it to other software such as X foil or panel for windows . It display the airfoil to work on . It show small diagram of the foil before opening them . There is the possibility to save some info in one line of text in the airfoil dat file (first line). In order to do this just type any short comment in the "airfoil info" field then to save the airfoil give it a name in the "save airfoil" field and click the "save airfoil" button..

In order to superimpose airfoil diagram first declutter the screen by a click the "refresh graph" button then just open the first airfoil file and in order to see the result click the "compute draw" button. now open the second airfoil file and in order to see the result click again the "compute draw" button . The first one is no more active but still displayed . Do not open a windows or put any graphic over the old foil because it will be lost (it is not loaded in memory any more) .

when doing global airfoil scale the resulting airfoil will be displayed superimposed on the precedent one and become the active airfoil . If you want to erase the previous graph in order to de clutter the screen click the "refresh graph" button then in order to see again the result click the "compute draw" button.

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