Grumman G-674 "Nutcracker" folding-fuselage VTOL fighter concept

overscan (PaulMM)

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Grumman Nutcracker project: Patent 3,966,142
 

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PopSci cover
 

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Mentioned in the text but without pictures - here it is: Grumman Nutcracker from Popular Science.
 

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finally Grumman Nutcracker 3-view
second image from Air Pictorial via 'Barrington Bond'
 

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Hi,

also the Grumman Nutcracker.

http://ilia13.dubki.ru/index.php
 

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From Aviation & Marine magazine
 

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Topic split and renamed. Here is a "compilation" in poster form of the Nutcracker's patent artwork:
 

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Source:
http://www.rcgroups.com/forums/attachment.php?attachmentid=1767491
 

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What is the point? Why not pivot the whole airplane and save the weight of the hinges?
 
Aviation Week & Space Technology September 20, 1976 pp. 16-17
Aviation Week & Space Technology September 20, 1976 pp. 18-19
Aviation Week & Space Technology September 20, 1976 p. 15
Aviation Week & Space Technology March 01, 1976 p. 12
 

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Bear with me for a moment but, how on earth can that ever work? Can anyone demonstrate the process? Not wanting to be funny or nasty but I cannot see that system ever working.
 
Awwwww, it's so silly that it's cool and makes for a great model.
 
Bear with me for a moment but, how on earth can that ever work? Can anyone demonstrate the process? Not wanting to be funny or nasty but I cannot see that system ever working.

It works by maintaining the thrust vector through the center of mass.
 
How can the thing take off and land vertically with a bendy fuselage and the undercarriage where it is in those pictures? I cannot see it being a starter even. Sorry.
 
During the JSF competition, a lot of people outside of Lockheed Martin said the lift fan/gimbaled nozzle VTOL system would never work (before it did).

The sky is falling types always come out of the woodwork when someone is trying to do something new. Opinions from those outside the programs are usually just wrong.
 
The airplane hooks into the probe first. Then the landing platform is raised up so the nose landing gear rests on it. Note that its aft section is initially hinged downward like the aft fuselage so the main landing gear can touch it. The aft section of the platform is then pivoted to horizontal as the aft fuselage pivots up to horizontal. Presumably the main landing gear wheels are somehow restrained to the hinged platform when it is vertical so the engines can be shut down while it is raised (the patent application was a little vague in that regard).

Nutcracker Landing.png

Also see https://patents.google.com/patent/US3966142A/en
 
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These articulated VTOL plane ideas are all kinds of awesome. I'm having trouble picturing how the transitions in flight to and from vertical are supposed to happen, all sorts of moments working on the whole there. I guess some enterprising team could at least build a UAV prototype, with modern tech the challenge can't be insurmountable and the exercise should indicate whether there's further potential. The whole thing also reminds me of another landing method, namely biomimetic perching, perhaps even a more daunting challenge.
 
The CG will auto align with the lift vector in vertical mode if there is enough degree of freedoms built in the articulation and speed is kept low.
That's exactly the same configuration of an outside cargo hanging under a line (the hook is sliding inside a hoop to cancel most of the loads resulting from both system aligning each others).
The line take out most of the dynamic forces that comes with speed. An articulated link can't do that easily (often rigid links). Hence speed has to be kept low.
 
Something is strange here. The Shimrit hydrofoils did not look like this boat.
 

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Did they plan to electronically stabilize the hook/refuelling basket ala. British Skyhook? Skyhook was a 1980s project to land a Harrier VTOL jet fighter on a frigate. The plan was to hover the Harrier alongside the frigate and have it dock on a gyro-stabilized crane that incorporated a re-fuelling hose and hooks. Once hooked, the crane would swing the Harrier inboard and lay it on a cradle for re-arming (bombs and rockets) or maintenance. I suspect that Skyhook failed because they could not convince 1980s vintage electronics to think fast enough to zero out the sip's rolling, pitching and yawing in rough seas. A ship can roll 30 or 40 degrees in heavy seas.

Nutcracker could eliminate all that fancy fuselage articulation simply by hanging a visual target above the basket. That way the pilot would lay on his back aiming for a target (e.g. tennis ball) suspended overhead ... er ... straight in front of his windshield. The entire fuselage would point straight up during landings.
 
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