For visitors to my website, this “Build of the Month” (BOTM) Series is meant to help those who are trying to get started in building their own Radio Controlled (RC) model aircraft.

 If you are currently not an active builder, and you want to be, this webpage would be a great place to start. If you have an RC model aircraft that you would like to see featured in this section or feel others may find interesting, please let me know and I will make every attempt to find scratch build plans, photos, and maybe even a published build article, which I will then post in a future BOTM edition. Just send me an email @: Build of the Month.

PLEASE NOTE - All prior BOTM Editions are now available for you viewing pleasure @: Build of the Month Series Archive.

NOTE - You can view all images in a “Spotlight Box” by simply clicking on any image.

Build of the Month WW-II Mini-Series - November 2024 Edition

 I hope you enjoyed last months BOTM WW-II Mini-Series 1st Edition on the Junkers Ju-52/3m model. If you have an RC model that you would like to see featured in this section or feel others may find interesting, please let me know and I will make every attempt to find scratch build plans, photos, and maybe even a published build article, which will then post in a future edition. Just send me an email @: Build of the Month.

 Ok, now lets see what I have for the month of November 2024. Continuing with the “BOTM WW-II Mini-Series,” for the 2nd edition how about an aircraft that was used by several nations during the war and has an unusual layout with the engine installed in the center fuselage, behind the pilot. So given these requirements, this 2nd edition of my BOTM WW-II Mini-Series features the Bell P-39 Airacobra, a fighter produced by Bell Aircraft for the United States Army Air Forces during WW-II.

     

 The Bell P-39 Airacobra is a fighter produced by Bell Aircraft for the United States Army Air Forces during WW-II. It was one of the principal American fighters in service when the United States entered combat. The P-39 was used by the Soviet Air Force and enabled individual Soviet pilots to score the highest number of kills attributed to any U.S. fighter type flown by any air force in any conflict. Approximately 9,560 Airacobras were produced, about half of which were sent to Russia under the Lend-Lease program. Production models of the P-39 started arriving at Air Corps squadrons in January 1941; six months later the first Airacobras reached England. The British had planned to order 675 of the planes, but after disappointing combat experience, the order was canceled. Other major users of the type included the Free French, the Royal Air Force (RAF), and the Italian Co-Belligerent Air Force.

 The Bell engineers wanted to mount the cannon so it would fire directly through the propeller shaft. This meant the engine would have to be located deep in the fuselage. This, in turn dictated that the machine would have a tricycle gear undercarriage -- the first such ever used on a production fighter. It had an unusual layout, with the engine installed in the center fuselage, behind the pilot, and driving a tractor propeller in the nose with a long shaft. Although its mid-engine placement was innovative, the P-39 design was handicapped by the absence of an efficient turbo-supercharger, preventing it from performing high-altitude work. For this reason, it was rejected by the RAF for use over western Europe but adopted by the USSR, where most air combat took place at medium and lower altitudes.

 Together with the derivative P-63 Kingcobra, the P-39 was one of the most successful fixed-wing aircraft manufactured by Bell.

     

 “Note” the images above showing a completed Airacobra model and the plans were found online @: Outerzone Bell P-39 Airacobra Webpage.

 RC MODEL CONSTRUCTION: The model featured this month is a discontinued Gold Edition kit from Top Flite. The nice thing about the Gold Edition P-39 Airacobra is that although it is a highly detailed scale model with all the goodies, such as a realistic looking scale outline, built up tail surfaces, retracts and flaps, it is one of the few military aircraft that had a tricycle gear configuration. Those of you who have not yet mastered airplanes that are tail draggers will appreciate this model's great ground handling characteristics.

 The plans are enormous — but they include dotted lines which indicate where best to cut them apart for ease of handling. Even better, the centerfold of the instruction booklet is a reduced copy which is easily detached and handy to have when the structure being built covers a detail you wish to see.

 TAIL SURFACES: The tail surfaces are built first. Following the Top Flite method of construction produced the truly beautiful symmetrical and tapered surfaces which are so much more realistic than the usual flat sheet tail parts. Each rib has its own jig tabs to assure perfect alignment and allow sheeting the complete topside without a twist. The control surfaces all have sheet balsa cores to maintain the outline shape and 1/16" balsa strips which are glued in place then sanded to yield scale-like structures.

 FUSELAGE: The basic construction of the fuselage consists of top and bottom halves built over the plan on a horizontal crutch. The engine (.61 upwards) is side mounted on the right-hand side. Using the excellent booklet photos for guidance, it should be straightforward to build the basic crutches..."

 WINGS: These are built upside down over the plans. A full depth 1/8” balsa spar web is placed in position with all the ribs being slotted into position. Basswood spars are glued either side of the web, resulting in a strong, lightweight structure. A trailing edge web is also glued in place, which has an embossed line, which keeps the ribs at the correct height from the board. Again, an instruction manual with a photo and details on every piece of wood you glue, make it practically impossible to get into problems.

 FLAPS: The Top Flite P-39 Airacobra is designed to incorporate scale split flaps; however, flaps are optional and not necessary for an excellent flying experience. Without flaps, the takeoff roll is a bit longer and the landing speed is slightly faster. If you do not wish to build the flaps, just disregard parts of the manual involving flap construction. The flaps are not difficult to build, but they do require good craftsmanship to fit and operate well. Flaps add nicely to the model's flight characteristics and scale appearance. Trim changes should not be needed when flaps are extended. The only exception is when they are deployed when flying at full power. The trim corrections are discussed later in the manual during radio set up. For flaps you will need one additional standard servo.

 RETRACTABLE LANDING GEAR: You may build your P-39 Airacobra either with fixed or retractable landing gear. The instruction manual provides detailed instructions on how to install retractable landing gear available from Robart. They are pneumatic to simplify installation and hookup. You may choose to use another type of retract but it is up to you to make modifications required to fit them.

 FLIGHT CHARACTERISTICS: During Top Flite flight testing they found no bad characteristics in this airplane. Take-offs were straight forward with good ground handling. The plane was airborne in approximately 100' [30m]. Once the plane is flying it goes exactly where you point it. Rolls are very scale-like with the low rate settings. At high rate it can roll more like an aerobatic sport plane. Power-off stalls were very soft and predictable with only the nose dropping in the stall. There was no tendency for the plane to tip stall. Landings were straight forward with or without the flaps. Without flaps you should maintain a bit more airspeed on your approach. With full flap deployment the plane slows very nicely and allows for a very soft landing. Unlike some models, the P-39 Airacobra does not exhibit any pronounced ballooning when flaps are deployed. A full flap landing will generally require a little steeper approach than an approach without flaps. Try setting up your approach from a slightly higher altitude than you might typically use for a landing without flaps. Deploy full flaps and gradually decrease the power. Keep the nose down and maintain a consistent approach to the beginning of the runway. When you are over the runway threshold pull off all power and the plane will settle in nicely to final touchdown. If you have never flown with flaps this is an excellent model to learn with. The extra effort to construct the P-39 Airacobra with flaps is well worth the effort when the model is completed.

 The Great Planes Top Flite P-39 will provide the scratch builder with a superb sport-scale model and a head turner at the flying-field. This model will be a joy to build and sheer pleasure to fly. In the air the P-39 is a lovely sight, with low passes being the best as you can see the air-scoop and under-wing cannons to good effect. Credit must go to Great Planes for their unusual Warbird and to Jim Sandquist, for the way the instruction manual is presented - it’s superb. I would not hesitate to recommend the P-39 to anybody wanting a different type of Warbird.

 The Bell P-39 Airacobra RC model in this months edition can be built from a set of plans and articles all from Outerzone which are available @: “Outerzone.”

Outerzone Bell P-39 Airacobra Webpage.

 I hope you have enjoyed this months selection, and just maybe, I have spurred some interest in trying your hand at building an RC model airplane.

Until next month - Keep the Balsa Dust Flying!!

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