Tu Bee (oz5862)

About this Plan

Tu Bee. Twin sport model for 2 x Bee engines. Uses a foam wing.

Quote: "While trying to settle on a project to use my new Ace micro flight pack, I ordered an Ace Guppy wing set. This wing is the standard Ace tapered foam wing with the bottom shaved flat. I felt that this thin wing (about 5/8 in thick at the root) could make an .020 powered sport model practical. It was about this time that a friend asked me if I wanted a new TD .020 that he had found buried in his junk pile. If I remember correctly, it took about 60 seconds to figure 1+1 = 2 (I'm slow sometimes). Now, this was the first time in my modeling career that I had two of something. I was determined to make the most of it.

My goal was to design an inexpensive, easy to build twin that could he flown by anyone who can fly a Quickee 500 type model. The design criteria was to make this a performance model. I did not want to make it a powered sailplane nor did I want to spoil the lines of a small model with a bulbous fuselage. With this in mind, I settled on a wing area of 135 sq in, and a maximum weight of 14 ounces (final weight was 12 oz). The fuselage .was designed around the Ace micro flight pack, then enlarged so that a Cannon Tiny Twin could fit.

The result is the TU-BEE. It is a fast, responsive, yet stable model. The only thing that limits how it is flown is the fixed fuel pick-up. Inverted flight is out except to shut down the engines.

I flew the TU-BEE at our club's Air Circus. The tendency while flying in front of the crowd is to show off. Prior to this time, I had been concerned about rolling the TU-BEE. If it stagnated inverted I could lose an engine and have a long engine-out flight. What I found out was that it will roll beautifully. I also made a few believers of those who thought that little engines don't have the necessary horsepower to make a model perform well. The TU-BEE has almost a one to one thrust to weight ratio. This is one model that you don't have to hand launch 'slightly down.'

Because there are two engines, it is guaranteed that one will quit before the other. Consequently, there are several techniques that will help you get the most fun out of your TU-BEE. First, time your engine run on a tank. Set your timer for this time minus 30 seconds. When the buzzer goes off, climb to altitude and half roll or loop to inverted flight. Fly inverted until both engines quit, then glide to a landing.

There is also a starting technique. First start each engine separately and run it for a minute or two to check your needle valve setting, refill the tanks, and start them both. As soon as the second one is running, top off the tank of the first one started. Now both engines should be running well and the fuel level should be almost equal in both tanks. What happens if an engine quits unexpectedly? The model will roll into the dead engine (you already knew that, didn't you?). With the TU-BEE, apply full opposite rudder, and if level flight is maintained, your wings will remain level. I have developed a technique for flying with one engine out. I hold full opposite rudder and use my elevator to control my direction. Nose high will cause a turn into the dead engine - nose low will cause a turn into the good one... "

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