Plan file details
Combo. Radio control aerobatic biplane model.
Quote: "Features from many outstanding biplane designs are to be found in this nimble handling ship. Combo, by Hans Hochradel.
The reason for designing and building Combo was that it was hard to find what I wanted in existing designs. Combo is a combination of the best of several biplanes. Many aspects of appearance, design and construction reflect the leading biplanes currently on the market. Combo's closest cousin is the Smith Mini-plane by Sig Manufacturing. This model is not a Miniplane. It may look like a Miniplane and have some parts and building similarities but that's it. A quick review of the technical data for Combo and the specifications for the Miniplane will show a great deal of difference. The flying characteristics are also completely different. Combo has clean simple lines of design. This philosophy follows in the building and flying characteristics.
A list of unique features of Combo follows:
1.) Six 1/4-20 nylon bolts hold down both wings
2.) Du-Bro ball link snaps to hold the interplane struts
3.) Sig Smith Miniplane Cowling
4.) Hidden Semco Pitt's style muffler
5.) Bridi dural aluminum landing gear with Gee Bee wheel pants
6.) One piece aluminum sheet cabane struts (no wires)
7.) Robart's Super Fueler
8.) CB Associate tail wheel assembly
This model is for the average flyer, and above average builder. If you've mastered take-offs and landings, but are having trouble with three consecutive rolls your flying ability is more than adequate. If you enjoy building models that look like full size aircraft and not a cross between Star Wars and high speed freight trains this is the model for you. Building this model is not for the rank novice builder. You should have a few successful trainers under your belt and be familiar with building terminology and procedures. If you hear yourself saying - no matter how many times I cut this piece, it's still too small - this is not the model for you.
For all hot shot pilots reading this, yes, a .60 size engine will fit under the cowling, and the airframe is strong enough to handle the stress. However, believe me, a good .40 size engine has more than enough power. Remember, 'scale' flying speed is a desirable element in a model. If you want a biplane bullet, this is not the model for you.
A word about acrobatics and crowd pleasing flying on Sunday afternoons may be in order. This model is definitely a crowd pleaser in looks and acrobatic ability. However, this model flies what is known as lite acrobatics. The master of this type of flying is Duane Cole of Texas. He flies a full-scale Taylor craft through some beautiful acrobatics. This type of acrobatics lacks vertical maneuvers, outside maneuvers, and tight maneuvers. So, you ask, what's left? (Or, what's so great about lite acrobatics?) Beautiful stall turns, diving for speed for nice round slow loops, unbelievable barrel rolls, and spins (like you see at airshows) are what's left. This is not a pattern aircraft, but it is crowd pleasing, realistic looking, and an easy flying biplane.
The prototype weighed just under six pounds, and with wheel pants on rough grass and no wind took-off in about 25 feet. Flying speed was about 35 miles per hour. This biplane flies like a trainer and landings are a pleasure. Being critical and listing the complaints of other flyers who have flown Combo, the elevator is slightly too sensitive and the ailerons are not sensitive enough.
To sum up beginners will be able to fly Combo, but should not attempt to build Combo. Some previous building experience is warranted, especially in a scratch built model that is a biplane. If you have read this far in this article you are the type of modeler that is willing to put the time and effort into a project like this and obtain all the rewards. Not the least of which is having a model beautifully different than the others at your flying field and one with crowd pleasing acrobatic ability.
Construction. Construction of the model follows established proven building procedures and techniques. Therefore, this portion of the article will not be a step by step description..."
Combo, Flying Models, September 1982.
Direct submission to Outerzone.