Douglas Export Attack (oz13926)

About this Plan

Douglas Export Attack (Douglas 8A-5). Rubber scale model.

Quote: "Many US fighting planes will soon sport the tri-color bull's-eye of the RAF under our recent 50-50 armament policy. And here we present replica plans for one of those new ships - a flying scale model of the Douglas Export-Attack. By Abe Shaw.

With the announcement by President Roosevelt of a program to share military plane production with the RAF, the British Purchasing Commission decided to forego certain available types and wait for the latest production models which are now rolling off the final assembly line of several aircraft factories. Among t h e newest types destined for service 'over there' are the Douglas 8A-5 Export-Attack Bombers.

These ships are modifications of the US Army Air Corps' types A-17A which were originally manufactured by the Northrop Aircraft Company, recently absorbed by the Douglas Company and now known as Douglas's El Segundo (the second) Division.

Externally, the latest version appears to be identical to the A-17A. Several changes in its interior and stepped-up power rating, however, have given the 8A-5 a good edge over its predecessor. The fuselage is all-metal aluminum alloy with semi-monocoque stressed skin. The wings are also of stressed skin metal construction. Trailing edge flaps are hydraulically operated as is the re-tractible landing gear. Tail surfaces are cantilever, of metal construction, with fabric covered rudder and elevators. Tail wheel is full swiveling.

Armament consists of seven machine guns and room for a substantial bomb load. Power is supplied by a Wright Cyclone which delivers 1200 hp and pulls the ship along at a top speed in excess of 265 mph. Recently the Norwegian air unit of the RAF received several dozen of the 8A-5 ships.

Fuselage Construction: of construction used in our flying replica of the 8A-5 is a smooth outer skin which simulates the metal covering used on the actual ship. Another feature is the hollowed out interior which in itself makes for extreme ruggedness. Such type construction, though, has its drawbacks, inasmuch as plenty of rubber power is necessary to keep the model aloft. However, the body is stressed to take it.

Select two knot free soft balsa blocks of identical proportions. Cement them together only lightly because they must later be separated. Trace the side view of the fuselage on both sides of the block and remove all excess wood with either a sharp knife or a small block plane. When this portion is shaped, trace the top view outlines onto the partially-shaped body and continue to cut away until semblance to the actual fuselage is obtained. Use successive grades of sandpaper to smoothen the surfaces. While this is in procedure, check from time to time for alignment with the fuselage cross-sections which are shown on Plate 2. These are cut from stiff paper.

Carefully pry apart the blocks with a long, thin-bladed knife. Now, make another inside template by following the series of dotted lines shown on the fuselage plans. These outlines, starting from the tail end, follow about 1/16 in below the outside line up to the glass housing, underneath it, and in front to the rear of the cowling. At this point, the cross-lined section of the cowling indicates the thickness necessary at that area to add weight to the nose. The under portion of the body follows along the same wall thickness out to the tail end, where cross-section lines indicate a thicker area.

Once the inside lines are traced onto each half of the body, start by scooping out chunks of balsa. Work carefully and do not attempt to remove chunks that tend to tear up other parts of the body. Use a sharp knife and keep handy an adequate supply of rough sandpaper. When nearing the bottom of the shell, put aside the knife and do the rest of the cleanup work with sandpaper. Complete the inside job with smooth sanding.

Apply at least three coats of dope to both inside and outside of each shell and brush over lightly between applications. Join the shells by applying cement along the inner sides of each half. Press the shells together firmly and then wrap with stout rubber bands. Allow the shell to remain in this state for several hours. After the wraps have been removed, shape the tail skid and glue into position as shown..."

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