Douglas D-558 Skystreak (oz4849)

About this Plan

Douglas Skystreak. Control line twin, for 2 x .049 engines. From Hobby Helpers group #367.

Quote: "How do you make a jet look like a jet in the air - and still have a prop? Use two props and put the engines in the tip tanks, says this designer. It can be a bit tricky to fly but offers surprising, and unexplained, benefits! Douglas D-558 Skystreak, by Frank Beatty.

The air powers of the world began developing experimental jet-powered aircraft for possible military use during the early stages of World War II. The vastly greater speeds of these radical new craft posed innumerable design prob- lems, so few of these ships actually became operational or saw combat service.

Experimental work did not cease in this country at the war's end and the Douglas Skystreak was developed for the United States Navy to study these transonic speed problems, The Skystreak, truly a flying laboratory, carried a fantastic maze of instrumentation. For example, there were more than 400 pressure take-off points located on the wings and control surfaces alone to accurately measure air pressure distributions on these areas.

Few experimental efforts have been more crowned with success. The Skystreak passed its Navy acceptance tests in record breaking time, and priceless data were obtained during its flight test programs. An added bonus was achieved when Major Marion Carl USMC, flying the Skystreak, set a world speed record of 650.92 mph in August 1947.

What ship then could be more appropriate to use in our unusual power plant arrangement experiment than the experimental Skystreak? But hold on there, why power a scale jet model in this unorthodox manner to begin with?

The jet age is upon us. We see and admire these sleek craft everyday. Some of the most beautiful ships ever designed have been jet powered and yet in many years of model building and flying I can count on my fingers the number of scale jet models I have seen. Putting it in the old nutshell, few model builders will power a scale model that has required countless hours to build with a jet engine. The heat insulation problems, brick-heavy wing loadings, fire hazards and the jet engines' balky starting and running habits discourage all but the most dedicated. So what is needed is a more reliable method of powering scale jet models,

Several approaches using conventional gasoline engines have already been successfully demonstrated. Examples are the ducted fan jobs and the Sabre Stunt. So here is one more way to fly a scale jet aircraft using the old reliable gas engine. The engines positioned in the dummy fuel tanks at the wing tips are hardly visible in flight. And think of the many ships that used tip tanks or armament pods that can be modeled using this idea, The Grumman Panther, Republic F-84, and many of the Lockheed family including the F-104, to name a few.

Our Skystreak was selected for its straight-forward lines which would pose no unusual design or construction problems. The model has been built to a scale of one inch equals one foot and it spans 28-1/2 in, is 35-1/2 in long and the all up weight is some 26 ounces. Coloring is bright red with the appropriate national markings and two Holland Hornet .051's (use any comparable engines) power the Skystreak. Construction is conventional except for the engine placement - but do study the building and flight instructions; there might be a helpful hint or two in them!'

Construction: Start the wings by cutting out all the parts and making up the sub-assemblies. Cement several widths of 1/16 sheet balsa together for the wing skins. You will need four sheets approximately 8 in wide by 11 in long. While these skins are drying, cut out all ribs, tip lank bulk-heads, bellcrank mounting plate and ply-wood wingspar..."

Direct submission to Outerzone.

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