Mark's RC Powers F-22

Several months ago I decided to design and build a balsa flying wing. While researching flying wing designs, I came across RCPowers.com. They build planes out of foam instead of balsa which speeds up the build process and makes it easier to try out new ideas. This F-22 is one of their latest designs.

As I have said before, I'm really having fun building with foam. This plane took about a week of off and on evenings to build. I'm getting much better at foam building skills although some of my glue joints are not as clean as I would like. This plane looks the coolest of all the foam planes I have built so far. It was a nice looking plane before painting, but once it was painted, it really started to look scale.

I've recently read several books on aerodynamic. One of the books had a section on the KF airfoil which RCPowers recommends for this model. Per math found in the book, the step should be just over twice what is recommend. I increased the step by 6mm (the thickness of the form I'm using) which bring it to within a mm of what, according to the math, should be perfect. My worry is that the formula may not apply to fast flying jets. I was also able to build in a slight twist so my wing roots have more angle of attack than the tips. This should help with tip stalling although without ailerons maybe this is not such an issue.

I plan on flying it for the first time tomorrow if I can finish the odds and ends this evening.

The following day...

The plane flew great although it was a bit windy and I didn't have the correct prop installed. While changing props, the plane caught a gust of wind, flipped over, and one of the vertical stabilizers broke off.

The next day was not as windy but the battery came loose mid way through the flight. I'm amazed I was able to land without breaking anything. Great design!