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Building Tips and technical articles. => 1/2 A building. => Topic started by: john vlna on April 02, 2014, 06:26:14 PM
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I have wanted to build one of these for a while, so this week I whipped up a Northrop XP-56 Black Bullet. It was one of three experimentials ordered by the Army. I have built a XP-54 and it flies very well. Span is 20 inches, outlines are scale. I will use electric power with throttle. Still a few things to do before finishing, including the sub fin and leadout guide.
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Cool, John! Here's a motor for it!
http://www.hobbyking.com/hobbyking/store/__10591__CR23M_Contra_Rotating_BL_System1550kv.html
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That motor would be a bit much for this model, but would be neat for a larger one. If the first model flies well I'll Maybe build a bigger version. The real prototype had counter-rotating props.
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Gorilla Bob RC has contra-rotating systems! >:D
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That looks cool -- I can't wait for the flight report!
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John, you think way outside of the box. These are some really neat designs. I truly enjoy seeing them. Ken
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Thanks Ken
I always seem to be drawn to unusual designs, they don't always fly well though.
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But think of all the fun you have constructing the planes and figuring out the design details. H^^
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Doc
True true. My goal has always been to have fun with modeling.
John
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John,
Best of luck! ...Better luck than the first one or two flight attempts on the original... I think it broke the first test pilot's back on takeoff run. My memory serving me?
It might not be, as I seemed to recall this as XP-56, Black Bullet.
The USAAF (US ARMY Air Force, for you of the blue-suit generation) requested three highly experimental design proposals at the time. One is in the avatar image on Doc's post.
I think that was XP-52 ? Swoose Goose ? twin boomer with a wing planform like Vultee Vanguard - sweepback LE to the booms, then straight out to the tip, and swept forward TE all the way. There may be a three view of this one in one of the Wylam plans books. Too lazy to confirm that just now...
The third one - I forget its XP-designation, but suggest care when you pronounce its name - Asc-ender - oops, that's Ascender. Swept wing canard design with its Allison 1710 at the back of the wing root as a pusher... OF COURSE the name meant that the plane could climb, don't you dare think otherwise!
Final note on the Black Bullet - there was a series, possibly in the sorely missed Wings/Airpower magazines, about these three X-planes. I have it here somewhere. May have been in Air International, or Aeroplane (both Brit mags)... The Black Bullet's first attempt at flight did not have the bump upper fin area. AsIr, it may have started porpoising on the takeoff run - very short spacing between nose-wheel and mains - almost impossible to even think of catching up with PIO (pilot induced oscillation), flipped and tumbled to a stop. Very short coupled controls and a lot of mass concentrated in the middle obviously could not help stabilize or control such deviation until a lot of speed had developed. It hadn't. Test pilot suffered.
The other two were also pusher engine designs, and both reportedly suffered from lack of adequate cooling, particularly on the ground. Same fate later killed the XP-67 Moonbat. I mean killed it. Hangar fire (when testing?) ended that blended wing/fuselage McDonnel prototype. The blended wing/fuse layout did much better on McDonnel's early Navy jets.
Somewhere on the web there is some motion imagery of the XP-67 in flight. GREAT stuff! Maybe a search on McDonnel XP-67 will find it for you...
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yes there were three pushers built to the same spec. the Vultee xp-54, Curtiss XP-55, and Northrop xp-56
I have built the XP-54, it is a good flier, hope the xp-56 works as well. I haven't had much shop time lately so progress is slow but I am finally ready to paint.