Northern Eagle (oz6131)

About this Plan

Northern Eagle. Pattern plane for .51 - .60 power.

Quote: "Sculptured lines mark this exotic machine. A marriage of Controline and R/C thinking. Slight on room, but great performance. The Northern Eagle, by Dave Gierke.

The 'Northern Eagle' was conceived in the Fall of 1968. It was intended to transfer controline stunt design and styling into the radio control field.

Ralph Perillo and I each built a version of the basic design concept specifically for the Toledo Mid-Winter Show of 1969. My model was completed in time for Toledo where it won best finish and best sport design category. Ralph's model was completed in time for the Buffalo show where it won best design.

For those of you who are familiar with the controline flying events you will probably see a resemblance to certain design types, as exemplified in the Eagle. To some people the aircraft looks like a team racer while others see a definite stunt influence.

The model was set up to fly full pattern competition. Wing area is only 600 square inches but performance, especially in high wind conditions, proved to be impressive, as exemplified by Ralph's initial flight testing. My Toledo version of the Eagle was never flown and now rests comfortably on the conference table of Bernie Paul of Associated Hobby Manufacturers in Philadelphia. Bernie made me an offer I couldn't refuse at the Toledo Show.

During the design phase it was decided that a swept-back wing would be advantageous to superior performance. This, however, created problems concerning tank location and radio equipment space. Notice that the wing root has located itself quite far forward on the fuselage. With the advent of very small, lightweight radios the equipment space problem with the design has diminished somewhat. We utilized a 225 milliamp battery pack to conserve on space with the original model.

A sidewinder engine was chosen as a matter of operating convenience. For some reason a stunt engine seems to be a real pain in the neck to set-up and operate from the inverted position. Inverted engines are not impossible for stunt, but they offer a considerable handicap to the serious competition flier. The radial mount concept was utilized in order to maintain a clean, low, frontal area nose section. Blind mounting nuts are used behind the 1/4 in firewall.

Initially the aircraft was designed to run a Super-Tigre .51 for power. It has successfully operated on this as well as with a variety of 60's. With a Veco .61 the ship is a real bomb. One problem with the .60 size engine is having a large enough fuel tank in which to complete the entire pattern. Actually, the K&B .40 front valve engine with Perry carburetor is ideal if the total model weight is kept below about 6-1/2 pounds.

As you can see, the original model was equipped with fixed landing gear. The model was never tried with retracts because of the nose gear space problem.

With the new retract systems (especially pneumatic) it may be possible to fabri-cate a retractable nose gear. However, Northern Eagle functions admirably the way it is.

The knife-edge maneuver was found to be impossible using the smaller power plants. Air frame speed (relatively low) combined with the small fin/rudder area is the culprit. With the larger engines the fin/rudder area is quite adequate with increased speed. If a .40 size engine is to be used, I would advise adding about 30 square inches to the fin/rudder combination (20 sq inches to the fin, 10 sq inches to the rudder).

From the photographs, you will notice that there is considerable sculpturing performed on the fuselage/empanage unit. On my version you will notice the dual exhaust exits on the fuselage. These were eliminated on Ralph's model, thus saving considerable time. Also note the stabilizer fairings. These fairings were primarily added as a visual consideration. They do, however, add a certain amount of struc-tural stability to the empanage. These may also be eliminated if you wish to save construction time. More time may be saved if you wish to go without the cockpit detail. In the final analysis it is left to the individual, the amount of effort to which he will exert himself.

Since there is a considerable amount of sculpturing involved with this model, the block construction method was utilized. All fuselage/empanage blocks were tack glued in place with cellulose cement and shaped to final size. The blocks were then broken apart and hollowed to save weight, especially in the aft section. Final assembly was made using Tite-Bond glue.

Initial construction is started with its wing. The wing, as you can see, is of foam core construction, sheeted with balsa wood. The airfoil sections as shown on the drawings are used as the root and tip templates. The airfoil sections are 64-018 root and 64-012 tip. The root section is less efficient than the tip, thus it tends to stall first, initiating tip stability..."

Quote: "Accept my congratulations on the website, a great job, especially for us who like the old projects, I found plans that I never imagined getting! Thank you so much! Here's my contribution: The Northern Eagle, an original model by David Gierke, published in 1973, with influences in Pattern and military style. Said to be very capable and fast model."

Direct submission to Outerzone.

Update 06/07/2017: Replaced this plan with a clearer scan, also now added article pages, thanks to Circlip and RFJ.

Supplementary file notes

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