Buzzard Bombshell (oz14503)

About this Plan

Buzzard Bombshell. Radio Control Assist Old Timer model.

Designed by Joe Konefes, the Buzzard Bombshell (oz5360) was originally published in Air Trails, Oct 1940. This here is a later kit plan, modified for RC from MEN of Norwalk in the 1980s.

Direct submission to Outerzone.

Attached kit review from FM, Aug 1984.

Quote: "Review: Model Engineering of Norwalk's Buzzard Bombshell. By Dick Sarpolus. R/C assisted Old Timer events recapture the yesteryear of modeling. This remake of a classic is a time proven contest winner.

I think Old Timer R/C flying is great! Not because of nostalgia, as I really wasn't born when many of the Old Timer aircraft were designed, but because of the fun of the event. It's the only type of R/C power duration event we have; it combines the thrill of an engine powered fast climb upward with the excitement of silent, majestic thermal soaring flight after the engine cuts off. I enjoy both parts of each flight.

SAM, the Society of Antique Modelers, refers to the event as Radio Control Assist Old Timer and Antique Models. The preamble of the SAM rules explains their intent, and I quote: The competition flying of free flight model aircraft of vintage design is intended to be casual, enjoyable, and interesting for both competitor and spectator alike. It is neither desired to advance the state-of-the-art of aeromodeling, per se, other than to increase participation in the sport generally, nor to reprove again that which is already recorded in aeromodeling history books. The intent of these rules is to categorize the basic types of vintage models and establish an equitable and simple framework of regulations for competition purposes.

SAM stresses having fun as the main part of flying Old Timers, but there is enough pressure at the contests for the die-hard competition fan, if that's what you're looking for. I like the competition, the relaxed atmosphere, the camaraderie, the bean feeds, and the modeling history that is apparent in the varied aircraft designs.

One Old Timer meet in particular inspired me to build the Buzzard Bombshell to be discussed in this article. A local Old Timer club, the Over-the-Hill Gang, has been holding the Jack Florenzie Memorial Meet for the past several years. The Contest Director is Joe Corneille, and this genial gentleman hosts such a relaxed, fun meet, usually including a lunch break and an after-the-meet party, that I just had to have an Old Timer so I could enter this contest.

Old Timer kits are available in a limited selection, many made by 'small business' enterprises. We're fortunate that some modelers have put in the necessary effort to make these kits available. Most of the aircraft seen at meets are scratch built, from plans that have been reprinted in various model magazines or are available from such sources as John Pond's vast collection of antique model plans. Remember, the planes to be used must have been designed prior to December 31, 1942, or December 31, 1938 for the Antique class.

The MEN Kit: An Old Timer I'm fond of is the Buzzard Bombshell, designed by Joe Konefes. The original Bombshell won it's free flight class in the 1940 Nationals, and it had one flight of 49 minutes! It's a cabin design, which I prefer over the pylon types. My main reason for building one was that MEN, Model Engineering of Norwalk, produces a prefabricated kit and I wanted an Old Timer as quickly as possible.

The Bombshell has 850 square inches of wing area, and under SAM rules the maximum glow engine which can be used is a .36. I naturally wanted a powerful engine for competition use, and since an R/C throttled engine is not needed, I planned to use a control line combat engine. The rules permit an engine run of twenty seconds, with the maximum flight time being seven minutes. I figured a Bombshell with a good .36 engine would be a competitive class C Old Timer.

The MEN kit is a faithful reproduction of the original design, with provisions for the RC rudder and elevator controls, and some strengthening of the structure for the rigors of today's Ft/C flying. This model is suited not only for Old Timer competition, but also for sport flying and as an easy-to-fly R/C trainer, with less than .36 power. For training and sport flying a .19 or .25 will provide plenty of power for good flying.

I built the wing first, and found it unusual in that the first step is to glue the spruce spars to the leading edge planking. The trailing edge sheeting also receives an attached spruce spar. These spar/sheet parts are placed over the wing plan, followed by the wing ribs. Vertical grain spar webs are placed between the ribs and the top spar/sheeting pieces are added. The result is a fully webbed spruce/balsa I-beam spar configuration and a very rigid wing. Most Old Timers must be beefed up for use with today's better engines; I'm sure that with the MEN Bombshell we do not have to worry about breaking a wing in flight.

The tail surfaces are extremely light weight. It's good that they are, because the tail section of the fuselage is very long and with the short nose, excess weight in the tail would be tough to balance out. Made up of strip balsa stock, with the use of an instant cyanoacrylate glue, the tail surfaces are quickly built.

The fuselage construction is again surprising, with the main fuselage side pieces being made of plywood. It's light poplar plywood, with plenty of die cut holes to save weight. This light plywood tends to warp before assembly, and care must be taken to build a straight fuselage. This was the toughest part of building the model for me. I finally resorted to adding 3/16 inch square balsa strips diagonally between the fuselage bulkheads, trimming them to force the sides into alignment, and gluing the bulkheads and diagonals in place one section at a time toward the tail. The final result was a straight, rigid, light fuselage.

Transparent MonoKote was used for a quick, light finish and nylon tube controls for the rudder and elevator. A slight modification I made was to install grooved hardwood landing gear blocks across the fuselage bottom with the landing gear permanently installed and plywood equipment access hatches held in place with small screws.

I obtained a Fox .36 Combat Special for power. In my area use of a muffler is mandatory, but it's not easy to add a muffler to this Fox. Expert machinist and long time modeler Charlie Williams machined some adapter pieces for a muffler retention scheme which has worked out well.

Fuel cut-off for the twenty second engine run is simply a piece of 1/16 inch wire, bent to squeeze the fuel line when pulled by the servo; works fine. A two ounce fuel tank was installed; it's far more than necessary. My completed Bombshell, ready to fly, weighs 4-1/4 pounds for an 11.5 ounce per squre foot wing loading. I had added fiberglass and epoxy around the wing center section, and used more epoxy than necessary in the fuselage construction; the plane can be built even lighter. It balanced perfectly with no weight required for trimming.

I first ran the Fox with its intake restrictor, but quickly removed it for maximum power. Muffler pressure was used for steady fuel feed and a 9-6 prop seemed to work best. With only several test flights on the new engine and plane, it was ready for the Flying Models June 1983 Old Timer Contest.

This affair has been reported on in FM, and I will only add that Joe Beshar did his usual fine job as the Contest Director while Flying Models hosted a great contest. The Bombshell and I were fortunate enough to find some thermals and go home with a nice Second Place trophy.

As further testimonial to the competition potential of MEN's Buzzard , we entered the SAM R/C Old Timer meet in Lincroft NJ, held in October 1983. Thermals were around and we placed First in the C Glow class. With only several dozen flights to its credit, the Buzzard has flown in two contests and collected a First and a Second. Not bad.

The Bombshell now hangs in my workshop, ready to go for contest use or some lazy summer day flying. Get into Old Timer activity and have fun!"

Supplementary file notes

Review.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction