I have had a chance to look at the Model Airplane News construction article from August 1945.
Certainly, the date qualifies this design for OTS.
However, the construction article is essentially a scale version of the XP-77. This model was not designed to be particularly aerobatic. Even though the full scale aircraft had a relatively thick, nearly symmetrical airfoil (according to 3-views published in that same magazine and the section also appears to be akin to some laminar flow sections as the max thickness will well aft and there is a reflex, top and bottom at the trailing edge) the model has a flat airfoil. The wing is small with a 33 inch span and has a relatively high aspect ratio. It measures out less than 150 square inches of area. This is not even the size of a modern 1/2A stunt ship. Trying to make this into any kind of a model for OTS or even any kind of aerobatics beyond a very "soft" wingover would be challenging at best.
I apologize for sounding so negative or discouraging about building this airplane for any kine of aerobatics, but unless this is built super light, there would be little chance of this thing performing. And what is meant by super light? At 150 square inches, it should weigh less than 10 ounces, 8 ounces or less would be a good goal, use a good strong 049 or even an 061, then it could be a fairly lively performer except the flat bottom airfoil will limit it to primarily inside maneuvers. Inverted flight might be possible, but it would look rather strange and probably very difficult to maintain any kind of level flight. Even with an 09 or a 15, this would start getting heavy for that wing area for anything other than level flight. With more power, there will be more speed and at least, it might be able to maintain a 45-degree elevation for level flight, but aerobatic performance will be challenged regardless of power plants and possible wing loadings.
This was originally flown with an ignition Forster 29 and Dick Everett, the designer, even suggested an Olson 60 or a Super Cyclone. Everett even suggested that the Forster was "enough ... for any stunting you may care to do." He also mentioned that this was his first control line model but did not explain if he really did any "stunting". It should be remembered that "stunting" in 1945 was viewed somewhat differently that what know now even for Old Time Stunt capabilities.
The XP-77 is certainly a unique looking airplane. Unfortunately, to the best of my knowledge, there are no other published designs for any control line versions of this airplane, either that would be legal for OTS or even for just a flying model of any kind or size.
Keith
Topic: Bell XP-77 (Read 937 times)