Plan file details
Pong. Radio control sport trainer model, for .049 power.
Quote: "This two-channel trainer has a Ping-Pong ball spinner to absorb shocks while learning. Pong, by LF Randolph.
A while back, at the beginning of summer, it seemed a good idea to build an airplane similar to the ones we used to fly years ago. The project proceeded through the design stage and into the construction of a wing and fuselage, then died. The good flying of summer was much more interesting than the re-design of an old timer. Then came fall with shorter evenings and the change of time. It was no longer easy to get to the field after work and yet the weather was even better than in the summer. The obvious answer was an airplane that could be flown in the front yard or on the nearby school ground. Up jumped the old timer idea again and Pong was born.
Pong, named for the ping-pong ball spinner that keeps it from breaking windows in case of improper landing site selection, is a re-design of a pylon free-flight I flew years ago in competition. It flew quite well then with an ignition Arden .09 for power, and with a few changes to improve its performance with R/C it flys quite well now. The nose is longer and the lifting tail is gone to move the CG forward. If anything, the glide is better than the original. The glide is important, for the cool, fall, evening flying provides gentle thermals from the warm roof of my house and the houses of my neighbors.
The usual flying procedure is to hand launch, climb above the trees, do a few loops and a roll or two and then climb until the fuel is exhausted and look for some lift. The landing approach is usually a dive below the trees then very tight circles to a landing in the street. Pong can easily perform 720° turns between curbs of the average city street. I don't know if Pong will take off or not, I've never tried it because it seems so natural to hand launch. A gentle push with the nose slightly down and the thing is flying - what could be easier. The gear is there to land on, that's why it's called a landing gear. The muffled .049 is quiet, and I have had no complaints from the neighbors. The power available is more than the old Arden provided and the total weight of the airplane is about the same.
Construction. Please, please build this airplane like an airplane and not like a boat anchor. There is absolutely no need to make anything stronger. In fact, some of the beef in the wing center section (webs) could be left out with no detriment to the strength. Every gram of extra weight must be paid for in reduced performance and more damage in case of hard landings.
Wing. In keeping with the desire to be inexpensive and at the same time nostalgic, make a printed sheet of ribs by cutting out a template from card stock and use it to draw as many ribs as you can on a sheet of 1/16 in medium balsa. One of the fine tipped fiber pens works great and about one and a half sheets of 3 x 36 inch stock should do it. Cut the ribs out and pin them together and sand them to the same shape with a sanding block then mark the spar notches on the top and bottom..."
Pong, Flying Models, May 1981.
Direct submission to Outerzone.