I've been looking for this kit for a long time, finally found one on eBay, received it today. Looking over the plans & instructions, I see the designer says the model does not have a lot of rudder authority. The examples he offers of how to use rudder are dramatically less than what I am accustomed to flying (and I'm not big on 3D!). Ordinarily I would have no hesitation to modify a design, but this model seems to be hallowed with a grand consensus as one of the all-time great, highly evolved designs--at least among those that have built and flown it--so I thought it might be good to seek advice before meddling with a proven winner. I'm just wondering if anybody with experience on this model can offer any insights pro or con on adding some rudder area, perhaps using some of the vertical stab as aerodynamic counterbalance. Comments on other aspects of building/flying this plane are also invited.

I have had two Aeromasters and have an original Andrews kit in my personal stash of kits waiting to be built. Obviously I think highly of this model. However bear in mind that this model was from a different time(I first saw one in the mid-sixties) when a different style of flying was in vogue and engines were significantly less powerful. IMO the flying then was smoother and with less radial snapping maneuvers. The Aeromaster excelled at this type of flight. I can't say, but would not expect one to fly like today's very light, overpowered Ultimates. It is a classic that was the best for it's time.

I flew that bipe in the 70s 80s and 90s I still have the one I few in the 80s and also the one flight my teacher and great frend Ted B.
had in the 70s.
To add a little area to the rudder is no problem it helps alot in knife edge flight.
As you know it gives you options on building the top and bottom wing ie. swept or straight,
I would suggest that you scratch build a top and bottom wing both swept so you can switch from top swept bottom straifgt or both swept or both straight.
It is one of the greatest bipes I have ever flown.
You might want to try a phaeton bipe by Balsa USA with a Saito .65 four stroke for some unbeliveable slow flight with landings you could almost walk beside.
So enjoy your bipe and forget the hype about tail draggers once you go bipe there is no other plane you would ever want to fly.

Happy landings Vic
PS.I have 2 built 1 in bones and 3 kits

Incredible airplanes these are! I had 3 at one time! Dad has one and a friend now has the second. The third has bolt on swept wings with a ST .90 in the nose. The first one I had was fitted with an OS .61fsr, what a great combo (dad did the same thing!). Yes it could use a "Little" more rudder, but I wouldn't go to any great length to do it though.

I have an Andrews Aeromaster as my mainstay plane right now. Been flying it for about 5 years. I've got a garage full of planes. I keep comming back to this one. I liked it so much I bought anohter and put it back just in case. I just love the way it looks in the air and how it flys. One thing I did change was the upper wing mount. I bolted mine on and added struts. I would recommend you build it to the orginal plans first and adjust the Center of Gravity. You can add rudder later if you have too. I doubt you'll want to though. Enjoy!

I flew one in the 80's. Absolutely wonderful airplane. I built mine with 52" swept top and 48" straight bottom wing and would do the same if I were to build it today. I agree with R8893, mine flew on the old K&B 61 with a 12X6 prop, and it would do most anything (flying, not the H-word). There are 46's today that put out about the same power as that old .61. I'm sure you will enjoy your Aeromaster.

I liked my first one so well I have since built 6 more and all were delightful. Four flew great right off the board but on three, I had to do some incidence setting on the upper wing. All seemed to like to have the upper wing at about 1.5 degrees less incidence than the lower wing. All mine were powered with Fox 60's but; were I building another, I'd up the power and enlarge the rudder. Right now I'm about finished with the Giant Aeromaster, hope it flys as well. Have a Quadra 72 on it.

I have a new, never flown Aeromaster. On others advice, I enlarged the rudder about 15%. The discussion on wing incidence is interesting. On real biplanes, Stearman, etc., top wing incidence is always greater than bottom wing incidence. Generally refered to as decalage. With top wing flying at a greater angle of attack (due to greater incidence), it will stall before bottom wing. This allows the nose to drop thereby decreasing the angle of attack, allowing the top wing to resume "flying". If bottom wing stalled first, then A/C would pitch up causing a more difficult situation. All this assuming A/C is being flown right side up.

Just info, not saying that R/C models are the same as real A/C.

Re wing incidence. On my Aeromaster, I just built it to the plans, not knowing to check the incidence, and it flew well. 6 years ago I built a Balsa USA Phaeton 90, and in my flight trim process, after discussion with Dave at B USA, I found that setting the top wing with a little (1-1.5) less incidence than the bottom wing made a big improvement in the aerobatic flight characteristics. The theory....? I don't know. I do know it works. My guess is that our models have such a much greater power to weight ratio than most full scale bipes, we don't need to have concern about "getting behind the power curve" in a nose high condition. FWIW

Based on experience with 7 Aeromsters, 2 Phaeton 40's, 2 Phaeton 90's, 1 1/4 scale Moth and two other bipes, ALL flew best with the upper wing at about 1.5 degrees less incidence than the lower wing. In fact some went from absolute dogs to pleasant fliers by just reducing the incidence of the upper wing. Now all these planes have the upper wing leading the lower wing, if the stagger were negative, results may be different. If you were flying free flight or going for maximum lift versus minimum power, the the other way may prove better but; for ease of flying and pleasure, I like the upper wing at a lesser incidence.

Rodney,

To make sure I understand, your saying you want the upper wing's aoa lower, ie the front of upper wing lower so the bottom wing stalls first? What if the upper wing is raked back and the bottom wing is straight?

Yes, upper wing has less angle of attack, makes no difference as to the sweep of the wing. You will find, due to the way the wind flows through the wings on a bipe, that the lower wing will not stall first. If you can, design the wing attachment so that you can experiment a bit. I tried many different arrangements on at least 12 different bipes, 7 of them being Aeromasters, and on all, they flew best with the upper wing at a lower angle of attack than the lower wing. Now, you could get them to fly with different arrangements but performance suffered. Now, if you only want efficiency at level flight and are willing to sacrifice maneuverability, then you can have the upper wing at a higher angle of attack and still trim for stable flight. When I did have such arrangement, I found that trim for level flight was much more difficult or critical with the plane having a tendency to gallop; i.e. pitch up and down during level flight like driving on a bumpy road.