Mustang Fever
Posts: 1197
Joined: 11/30/2003
From: Cadillac,
MI, USA
Status: online
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Rod:
I think you'll find the D-7 is designed for a two stroke, the way the Camel was. You can put another type of engine in it, but it will look best with whatever size two stroke they're specifying. It also sounds, from bbrundle's description, like they have a special muffler for it so that everything fits into the cowl. I believe it's been designed for the Evo 61, and will probably look and fly best with that engine.
WWI scale models, biplanes and triplanes, have a number of characteristics in common:
1. Short distance between wings and stabilizers.
2. Extremely light wing loading for their size. (15-16 oz per square foot is common; other scale birds in this size range will run twice that and more.)
3. Narrow track landing gear in relation to the wingspan.
4. Stabilizer area is a smaller percentage of wing area than almost anything I can think of. (check the horizontal stab area of your trainers, including the elevators, as a percentage of the wing area. It's probably around 25-30%. With WWI birds, you're lucky to get 15%, usually less. The Hangar 9 Camel is about 12%, if memory serves.)
5. Lots of weight concentrated forward of the wings, and behind the face of the cowl, in order to balance them.
All these taken together result in airplanes that, compared to your trainers, are:
1. Sensitive in pitch. An elevator input that results in a moderate climb on your trainers will result in a stall and possibly a spin on WWI birds, depending on a number of factors.
2. Unable to handle the lightest crosswind. The wind will get under the wings and flip the airplane over just when you think everything is ok on landing rollout. Rule number 1 is: never takeoff or attempt to land in a crosswind. Rule number 2 is refer to Rule number 1. I'm not exaggerating.
3. A tendency to be ok with the tail up, right until the critical angle is passed and all that weight in the nose pulls it over.
My advice: go ahead and get it for Christmas, but go build a .25 size Piper Cub first, and learn to handle it on the ground and fly it well. It has about all of the nasty characteristics of the WWI birds, except maybe the pitch sensitivity, and costs about 1/3 as much. Once you learn to fly it smoothly, then try the expensive WWI bird.
It's a huge temptation to jump ahead too quickly in this game. Flying those trainers, you have no idea how rough you are on the controls. Smoothness and progressiveness on the controls is critical, as is patience. (I use lots of expo on the elevators on my two birds to help with smoothness.)
I was given all the same advice I'm giving you, and went ahead and bought a Great Planes DR-1 triplane anyway. It would look a lot better than it does today if I had listened.
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Bob Hunt
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RE: Hangar 9 Fokker DVII - 
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