Fokker DVIII

[Don Cooper]

Here is a picture of my recently completed Fokker DVIII. I started with Earl Stahl plans for a 57" span free flight. I scaled them down to a 36" span, took out the dihedral and added ailerons. I used an undercambered airfoil (I don't remember which one off-hand) which, per PROFILI, has a high CLmax and benign stall. Tail surfaces are from sturdy board foam. The plane is covered with SoLite. I am using a BP 8Y brushless motor. It weighs 91/4 oz. without battery.Considering the short nose, I was pleasantly surprised to find the C.G. came out at about 25% chord without the battery.

[Don Cooper]

Here is another picture. I got one flight in last week before it got too windy and it has been windy and/or raining since. I didn't find any nasty quirks during the flight and the stall is indeed benign as predicted by PROFILI. However, I was surprised at how fast the cruise speed was - too fast for my 75 year old reflexes. I had the wing, horizontal tail and thrust line all at zero degrees and the C.G. at about 25%. So, maybe if I increase the wing incidence and move the C.G. back a little, it will trim a little higher on the Cl curve and cruise a little slower.

[Debra]

Very nice! Are you interested in publishing it?

[Don Cooper]

Debra,
Can you give me more details as to what publishing it entails?

Don C.

[Mike Emilio]

Geez that looks pretty good. I have a set of plane for 69" for a 46 engine, but I think I'm going to have them enlaged to about 80".