All American (oz8518)
About this Plan
All American Pan-Am Plane. PAA-load model.
Quote: "Analysis of five outstanding payload designs which participated at the last National Contest in Dallas, Texas, produced this interesting pattern. Configurations studied consisted of those designed and flown by Lew Mahieu, Denny Davis, Wayne A. Schindler, Paul Gilliam and Frank Ehling - all noted contest flyers. The 'All-American' design resulting has been projected in somewhat larger size in a thoroughly tested model shown at left in photo form and at the right in detailed plans. Purpose of this presentation is to serve as a guide for original designing in the Pan American World Airways' 1952 PAA-Load events which again will be run off all over the country. These events will culminate in the big Nat's competition scheduled for Los Alamitos Naval Air Station in California which will be the site of the '52 American Champion-ships during late July, Pan-Am is offering cash and watch awards this year.
When five men work independently on the same design problem, normally we could expect five different results as each man will design according to his experience and local flying conditions. And if we were to look at the Pan American FAA-Load entries on the flying line we would say that the above statement is true. However, when these ,same models are drawn to a common scale and superimposed one on another we wonder if there is so much of a difference between them.
To illustrate the above point, we took five payload models, by different designers who specialize in the field, and superimposed their outlines as shown on the drawing. What would you say to their respective differences? It would seem that the five men came pretty close to the basic design.
The similarity does change some on closer inspection by taking the extremes for an example Frank Ehling's model has the shortest moment arm and also lowest aspect ratio wing. While Paul Gilliam, on other hand, uses a model which has a longer moment arm and higher aspect ratio wing. To make the contrast more pronounced, note that Ehling uses only about 35% stab on a short moment arm whereas Gilliam has 45% on a long moment arm.
Lew Mahieu's model was not specifically designed for payload. He also uses it, with success, for free flight. By having a long nose he was able to locate the CG so that it would not change if the passenger is removed or added. On the 'composite' outline we minimized this feature as it would have undue influence on the average.
The side views of the models varied considerably, especially the rudder areas. Compare Mahieu with Ehling on a similar moment arm. The fact that both models perform well, despite their difference in rudder areas, makes one wonder just how much tolerance one can have and still be safe. But, as most of us know, the design differences will cause different flight patterns, although in the end the duration may be identical. So on many occasions it may be the type of flight that may determine the actual layout of the design.
The main purpose of this comparison was to show the variations that can be had with one formula. And this may also be a good place to re-mind you that a winning model is not necessarily the ideal design to follow implicitly. Frequently a model may win because of local circumstances..."
Supplementary file notes
Article pages, thanks to Netmagick.
Did we get something wrong with these details about this plan (especially the datafile)?
That happens sometimes. You can help us fix it.
Add a correction
by Air Trails Design Board
from Air Trails
IC F/F Cabin
all formers complete :)
got article :)
Found online 06/03/2017 at:
Format: • PDFbitmap
Credit*: rchopper56, Newtmagick
Do you have a photo you'd like to submit for this page? Then email firstname.lastname@example.org
User commentsNo comments yet for this plan. Got something to say about this one?
Add a comment
* Credit field
The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.
This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.
© Outerzone, 2011-2022.
All content is free to download for personal use.
For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.
Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.