Stagger Bi MkIII (oz820)

About this Plan

Stagger Bi MkIII. Sport biplane model for Super Tigre.56 engine.

Quote: "For many of us, the biplane evokes a feeling of nostalgia for the early days of aviation. Although certainly obsolete for full-scale use, the biplane still has a definite place as a radio-controlled stunt aircraft. It has the advantages of compactness, light weight, and extreme maneuverability. In addition, we can absolutely guarantee that when flying the Stagger Bi, the spectators will pay little attention to any other model on the field!

The first Stagger-Bi was flown in the summer of 1959. It was a success from the beginning: very fast, highly maneuverable, and exceptionally spectacular in the pattern. Two years ago a cleaned up version was built, adding the tricycle gear. This is the ship shown in the picture.

For the technically minded, the theoretical advantage to negative stagger over positive stagger is that the decalage set-up of the wings is so arranged that the forward or bottom wing stalls first.

This gives better control at very low speeds due to the fact that the rear, or upper wing, is seldom in a stall condition. Also, the forward wing provides an air cushion during landings which makes for smooth touchdowns.

The plans show a considerable amount of modification in structure over that used in the original Stagger- Bi. The only drawback to the original was the tendency for the surfaces to develop warps due to the open-frame type of construction. Since the ship is extremely fast, this made it difficult to trim for all maneuvers during the initial flights. For this reason, the plans show a conventional planked type of construction. It is absolutely essential that accuracy be observed in order to avoid warps.

Due to it's speed and extreme maneuverability, the Stagger-Bi is definitely not recommended for the less experienced. For this reason, and since the plans are well-detailed and self-explanatory, only a few construction notes will be given.

Begin fuselage construction by cutting the 1/16 ply doublers and 3/32 sheet sides to shape. Be sure to cut notches in the doublers for bulkheads F2, F3, F4, plus servo mounts and tube for rudder bellcrank. Glue the doublers to the fuselage sides. Glue the 1/4 square corner longerons to each side and the 1/4 x 1/8 uprights to the sides and stab doubler. See the rudder bellcrank detail and assemble accordingly..."

Update 22/07/2014: Replaced this with a clearer plan at 300dpi, thanks to bulldogdrummond. Have kept the pd1 version as a supplement, since although lower res it does show the layout better - has the fuselage in one piece.

Update 14/09/2016: article pages, text & pics added, thanks to RFJ.

Supplementary file notes

Same plan but at lower res, better layout, thanks to pd1.
Article.

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