MrFowl
New member
Hi everyone!
I've been parusing the forums here for a while now without giving anything back *evil laugh* ...but it's time I finally give back. That said, I've chosen to compete in a challenge that I won't be able to show up at ...with a plane I might not be able to build. So this will be my first "real" contribution to the forums That said, I will try to document all my design thoughts, trials, failures, and successes so a new member will have a better idea how to go (or not go) about designing a scratch built plane.
I will be designing the XF-85 Goblin manufactured by McDonnell Aircraft Corp. "The smallest jet-propelled fighter ever built"!
First, some back story on the plane from the web if anyone is interested:
The XF-85 was a response to a United States Army Air Forces' (USAAF) requirement for a fighter to be carried within the Northrop XB-35 and B-36, then under development. This was to address the limited range of existing interceptor aircraft compared to the greater range of new bomber designs. The XF-85 was a diminutive jet aircraft featuring a distinctive egg-shaped fuselage and a forked-tail stabilizer design. The prototypes were built and underwent testing and evaluation in 1948. Flight tests showed promise in the design, but the aircraft's performance was inferior to the jet fighters it would have faced in combat, and there were difficulties in docking. The XF-85 was swiftly canceled, and the prototypes were thereafter relegated to museum exhibits.
STEP ONE:
Collect facts and gather general information about the plane you are interested in. This includes stability/flight characteristics if possible (this will give you a good idea if the design is even feasible). I do you his by googling the plane and compiling a list of facts/paragraphs as seen below. Bold text is important stuff.
It had an egg-shaped fuselage, three fork-shaped vertical stabilizers, horizontal stabilizers with a significant dihedral, and 37° swept-back folding wings to allow it to fit in the confines of a bomb bay. The aircraft measured 14 ft 10 in (4.52 m) long; the folding wings spanned 21 ft (6.4 m), wing area is 90 sq ft (8.3 sq m). A hook was installed along the aircraft's center of gravity; in flight, it retracted to lie flat in the upper part of the nose. To save weight, the fighter had no landing gear.
After the successful conclusion of two reviews of a wooden mock-up in 1946 and 1947 by USAAF engineering staff, McDonnell constructed two prototypes in late 1947. The Model 27D was re-designated XP-85, but by June 1948, it was changed to XF-85 and given the name "Goblin".
The tiny fighter was stable, easy to fly and recovered well from spins. However, hooking the Goblin in flight to its bomber’s trapeze was difficult.
The next steps are some basic preliminary designs and to start thinking about how it will be powered (EDF, pusher prop, ducted propeller...etc).
I've been parusing the forums here for a while now without giving anything back *evil laugh* ...but it's time I finally give back. That said, I've chosen to compete in a challenge that I won't be able to show up at ...with a plane I might not be able to build. So this will be my first "real" contribution to the forums That said, I will try to document all my design thoughts, trials, failures, and successes so a new member will have a better idea how to go (or not go) about designing a scratch built plane.
I will be designing the XF-85 Goblin manufactured by McDonnell Aircraft Corp. "The smallest jet-propelled fighter ever built"!
First, some back story on the plane from the web if anyone is interested:
The XF-85 was a response to a United States Army Air Forces' (USAAF) requirement for a fighter to be carried within the Northrop XB-35 and B-36, then under development. This was to address the limited range of existing interceptor aircraft compared to the greater range of new bomber designs. The XF-85 was a diminutive jet aircraft featuring a distinctive egg-shaped fuselage and a forked-tail stabilizer design. The prototypes were built and underwent testing and evaluation in 1948. Flight tests showed promise in the design, but the aircraft's performance was inferior to the jet fighters it would have faced in combat, and there were difficulties in docking. The XF-85 was swiftly canceled, and the prototypes were thereafter relegated to museum exhibits.
STEP ONE:
Collect facts and gather general information about the plane you are interested in. This includes stability/flight characteristics if possible (this will give you a good idea if the design is even feasible). I do you his by googling the plane and compiling a list of facts/paragraphs as seen below. Bold text is important stuff.
It had an egg-shaped fuselage, three fork-shaped vertical stabilizers, horizontal stabilizers with a significant dihedral, and 37° swept-back folding wings to allow it to fit in the confines of a bomb bay. The aircraft measured 14 ft 10 in (4.52 m) long; the folding wings spanned 21 ft (6.4 m), wing area is 90 sq ft (8.3 sq m). A hook was installed along the aircraft's center of gravity; in flight, it retracted to lie flat in the upper part of the nose. To save weight, the fighter had no landing gear.
After the successful conclusion of two reviews of a wooden mock-up in 1946 and 1947 by USAAF engineering staff, McDonnell constructed two prototypes in late 1947. The Model 27D was re-designated XP-85, but by June 1948, it was changed to XF-85 and given the name "Goblin".
The tiny fighter was stable, easy to fly and recovered well from spins. However, hooking the Goblin in flight to its bomber’s trapeze was difficult.
The next steps are some basic preliminary designs and to start thinking about how it will be powered (EDF, pusher prop, ducted propeller...etc).
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