Hi guys,

I was just doing a little research on Square Vs Rectangular Pattrenships.I found many interesting things and also did some behavior study with my own planes.

The patternships of the 70s & 80s had spans larger than their fuselages

Then came the new generation of square or almost square pattrenships

One thing which is important is the top Japanese designers with whom I found the continous trend of span smaller than fuselage by 5-8% like Akiba`s Good Shot, Grand Slam etc.

My question is this that smaller span than fuselage increases wing loading, stall speed, landing speed and penetration power, than a square design but is it really feasible for a patternship??
And what other advantages a smaller span aircraft has over its counterpart squared or larger than fuse aircrafts?

Thanks

There will be a lot of opinions on this one...

I think the main driver to Pattern design is "function, within the ruled parameters". Without trying to discuss the evolution of Pattern design in detail, (which I'm not an expert on, anyway) I'd say that each year's list of maneuvers has always forced certain design criteria, and that most (but not all) designers try to nearly fill the "allowable size" box, to decrease wing loading. But...

It's not all about span, as far as wing loading goes. Decreasing the aspect ratio can easily force more area into a shorter span. There's also a trend toward thinner airfoils than in the past. (approximately 10% thick, versus approximately 15% thick, several years ago) Designers will use traits that are "good" to them, although another guy with different habits and experiences may disagree. ALL aircraft designs are some sort of compromise, as you know.

Still, if you compare 100 Pattern planes today, (which I did, with a friend's help, a couple of years ago) you'll find the proportions very uniform for all but a very small percentage.

100 Patternships! thats great. James do you have a report or analysis of all these which you compared.If you could share it, it would be of great help.

Thanks

I've PM'd you.

The spreadsheet approach is a great one (and easy) for any type of design, not just pattern planes. For any type, just input all the proportions you can discover, and compare them. When you see how similar each "type" is, you'll see that all of us are basically re-designing minor improvements and/or cosmetic changes into "numbers" that are proven to work. An approach like that can give you more confidence in what will happen when you fly the thing, and is a great way to start.

Have fun.

When we did our EMC2 a number years back-- we went to a 12% root -10% tip and same fuselage/wing length --
also tall thin fuselage (6" wide).
Finally got out of the pattern business -
anyway this setup works very well for lots of rolling snapping stuff.
slow speed also.
pattern is dreadfully slow in evolving -
Our newest aerobat will be 80" span - 84" fuselage - 1900 squares - not for pattern - but scale aerobatics
most pattern "designs" are simply minor changes to a couple of standard layouts.
they all work --