Alšs Flying Oddities No. 2 The Waterman Aerobile By Al Backstrom There have been many attempts at building a roadable airplane, but one of the most successful has been the Waterman Aerobile. These mid-thirties airplanes were the follow-on to Mr. Waterman's Arrowplane that was entered in the government-sponsored competition for inexpensive airplanes. There were six Aerobiles built, including one after WWII. Paul Matt's Historical Aviation Album, Vol. III, has the best single coverage in one article that I know of. The Aerobile has often been modeled as a power model, but the only rubber version I know of was a 30" Megow kit that is badly out of scale in some areas. This simple version will allow you to sample this configuration with a small outlay of effort. The model is constructed of light 1/32" sheet balsa except where noted on the drawing. The only special or unusual point of the model is the wing which should have 6 degrees of washout and no dihedral. To obtain this, I assembled the two wing halves and pinned the center with the trailing edge blocked up 3/8" and the leading edge on the building board. Pin the wing tips flat to the board and glue the fuselage in place. When the glue has dried, fit the struts into the positions shown to maintain the washout. The six airplanes received different colors but all the pre-war airplanes had the color layout shown on the drawing. I used red in the dark areas and natural balsa in the light ones. In the photo you will note an uncorrected error in the coloring of the tip fins of my model, and some improvements in the version on the drawing. My model used a 5 1/2" Sleek Streak prop and an 10" loop of 3/32- FAI rubber for power. Some clay was required on the front of the motor stick to get it to balance at the point indicated. Double the rubber loop and test glide the model. I suggest you adjust the glide with the CG if the wings are as described above. If you have too little washout, try cutting out the elevon ends and deflecting them up. If you have less than 4 degrees washout, refit the struts. When the glide is satisfactory, reinstall the rubber as a single loop and wind about 200 turns and launch. If the model zooms up, add some down thrust. Remember down thrust on a pusher is obtained by moving the thrust line up at the CG, just like a tractor. If the model dives, add some up thrust. When a good pattern is achieved at low power, start adding about 200 turns each flight until you reach maximum turns. This should be about 1000. With the offset to the thrust line to the left, the model should have a natural left turn under power. If you want to increase the power and have the model glide down, adjust the glide turn with the tip fins.