Jul 162017
 

Every month, patrons of the Aerospace Projects Review Patreon campaign are rewarded with a bundle of documents and diagrams, items of interest and importance to aerospace history. If you sign up, you get the monthly rewards going forwards; the “back issues” catalog lets patrons aid the APR cause by picking up items from before they signed on. The catalog, available to all patrons at the APR Patreon, has been updated to include everything from the beginning of the project back in 2014 on up to February, 2017.

Below are the items from 2016 (and the first two months of 2017):

 

If you are interested in any of these and in helping to fund the mission of Aerospace Projects Review, drop by the APR Patreon page and sign up. For only a few bucks a month you can help fund the procurement, scanning and dissemination of interesting aerospace documentation that might otherwise vanish from the public.

 Posted by at 12:49 am
Jul 012017
 

The Pluto nuclear ramjet is often considered one of the crazier (or perhaps more accurately, “badass”) weapons systems ever considered by serious people. In short, it used a nuclear reactor as the heat source for an airbreathing ramjet; it would fly at a few hundred feet altitude at Mach 3 with nearly unlimited range. Several American aerospace corporations vied for the contract; LTV won the contract to build the airframe in 1961. The “Tory” nuclear ramjet was static ground tested with some success, but the program was cancelled in 1964.

Convair gave the concept considerable study from the beginning of the program in 1957 until at least 1961. Their “Big Stick” concept has been reasonably well known, but they had another idea that was somewhat further from the basic idea. It was mentioned in at least two briefings that I’ve come across; some amount of serious work was done on it, but the information I have is fragmentary. The concept was called simply the “Submersible Nuclear Ramjet.”

Pluto and Big Stick were unmanned cruise missiles. They would be launched from the ground with solid rocket boosters (some though was given to launching from ships, subs and aircraft) and would fly “grand tours” of the Soviet Union, spitting out a number of individual nuclear bombs. They would leave in their wake a line of ruin… the shockwaves from their passage would likely shake apart civilian structures, and the reactors would constantly spit out radioactive particles. At the end of the mission the missiles would crash into one final target.

But the Submersible Nuclear Ramjet would work a little differently. For starters… it was manned. There would be a crew on board throughout the mission.

Rather than starting off at some Air Force base, the Submersible Nuclear Ramjet would actually start off as a submarine, floating around on its own in the ocean. Propulsion would be provided by the nuclear reactor, serving as a “water ramjet” by heating seawater and expelling it. Feeding salt water, diatoms, kelp, fish and all the rest of the junkĀ  the ocean has to offer directly through a nuclear reactor seems a bit dubious.

When the order to begin an actual mission comes in, the propulsion system would be reconfigured from seawater-burning ramjet to seawater-burning rocket. The vehicle would expel stored seawater through the reactor, generating a large amount of thrust, enough to launch the craft vertically out of the water and up to high speed. The craft would then angle over towards the horizontal; the propulsion system would reconfigure once again, this time to an airbreathing nuclear ramjet. The vehicle would then fly a mission essentially similar to Plutos… low altitude, screamingly high speed, ejecting nuclear weapons as it goes. At the end of the mission, unlike Pluto it would *not* crash itself into one final target. Instead, the manned vehicle would return to secure waters and slow to subsonic speed. It would enter a vertical climb and slow to a stop; the ramjet would again reconfigure, this time back to rocket mode. Four drag brakes would deploy around the nose and the vehicle would back down into the water for a soft “splashdown.” It would of course land with nearly empty tanks, so it would be quite buoyant; until the tanks refill, it would likely sit tail-down in the water.

I’m going to try to find out more about this concept, but I have minimal hopes. I’ve gone all this time without hearing about it until just a few weeks ago.

Because why no, I’ve made a basic model of the concept. Complete accuracy is not assured… I have a top view and an inboard profile; as with a distressing number of concept aircraft diagrams, the views seem to conflict on things such as the cockpit canopy, and the inlet configuration is only partially shown. Still, it’s a really interesting concept.

If you’re interested in Pluto, take a look at Aerospace Projects Review issue V2N1. There is a very large, highly illustrated article on Pluto in that issue. If you are interested in the Submersible Nuclear Ramjet, keep an eye on US Bomber Projects… it will show up in the next issue or two.

The renders below show the Convair Submersible Nuclear Ramjet to scale with the LTV Pluto.

 Posted by at 12:36 am
Jun 132017
 

From the very early 1960’s, this piece of Hughes artwork depicts a hot-cycle “Helibus.” The “hot-cycle” was a briefly studied form of helicopter that did not mechanically drive the rotor, but instead ducted hot exhaust gas from a turbojet up into the rotor hub and then down through ducts in the rotors, exhausting out nozzles near the tips of the rotors. The exhaust gas would then push the rotor blades directly. The advantage was that since there was no direct mechanical linkage between the rotors and the fuselage, the torque that a helicopter normally needs to counter with a tail rotor would be largely eliminated. Thus this “Helibus” has no tail rotor, but it would still need to have some sort of reaction control thrusters at the tail to provide directional control at low speed.

Note that every row of passenger seats has its own door. This would greatly facilitate passenger loading and unloading, at some considerable weight and cost penalty. it would also firmly lock in seat pitch… as the engines are swapped out for newer, better, lighter, more powerful and less fuel hungry versions, the airlines drive would be, as we’ve seen, to pack more and more passengers onboard. But here the doors on the side have to precisely match the seat rows.

A vehicle like this would probably be used mostly to transport office drones from rooftop heliports in urban city centers to transport hubs out in the burbs or the sticks.

 Posted by at 5:23 am
Jun 112017
 

An old (1962 or before) piece of concept art from Kaman illustrating their “ROMAR,” a helicopter meant for Mars exploration. It appears to be powered by rotortip rockets, a decent enough approach for this sort of thing. However, this was before Mariner mars ’64, when the understood density of the Martian atmosphere dropped by more than a factor of ten. As a result, a helicopter like this would need to be made fabulously low-weight in order to fly, something improbable given the needs of a manned vehicle.

 Posted by at 7:42 pm
Mar 072017
 

Bell has unveiled a very sci-fi mockup of a “concept helicopter.” It features some unusual things:

A hybrid propulsion system

Variable geometry rotor tips

Lots and lots of glass

Only a single pilots seat

No physical control.

It’s that last one that’ll probably cause the most consternation. The pilot is meant to wear augmented reality goggles/visor/glasses/whatever; this will place data screens in front of him in an arrangement the pilot prefers. Control will still be manual, but the choppers onboard AI will presumably be able to track the pilots hands as he manipulates phantom controls.

Sure, it sounds cool, but two issues immediately present themselves:

1: Computer goes goofy. Malware, hacking, power surge, EMP, whatever… this thing seems like a deathtrap if the computer goes down.

2: Phantom controls that exist solely in the computers imagination and the pilots visor… sure, that sounds cool, and is certainly a common enough trope in sci-fi. Witness anytime Tony Stark wants to design anything, for instance. But in reality, your hands and arms get tired. You actually rest on the steering wheel or the yoke or the collective. Additionally, pilots really like to get direct feedback, which seems as yet beyond the ability to reproduce virtually. More, with every bump or jolt, the pilots hands will flail around. In a conventional helicopter, the pilots hands will be constrained by the controls they are gripping. In this one… nothing.

I would suggest a compromise: a set of *basic* physical instruments. Just what the pilot needs to safely fly the chopper. And I’d damn sure stick with physical controls. But… keep the augmented reality for the *secondary* instruments. Navigation, radio, air conditioning, whisper mode, thermal vision, fire rearward missiles… that can be via virtual reality. Instrument panels that are called up with a voice command, and recede when not in use.

Bell Helicopter unveils futuristic FCX-001 concept aircraft

 

 

Not at all related:

 

 Posted by at 2:14 pm
Oct 302016
 

I’ve been running the Aerospace Projects Review Patreon project for a bit over two years now. Every month, Patrons get rewarded with sets of aerospace history stuff… currently, one large-format diagram or piece of artwork, three documents and, depending on level of patronage, an all-new CAD diagram of an aerospace subject of interest. More than two dozen such packages have been put together so far and distributed. Given that you can get in on this for as little as $1.50 a month (for 125-dpi scans… $4/month for full-rez 300 dpi scans) and you get at least four items, that’s a pretty good bargain compared to the individual aerospace drawings and documents.

Patrons who signed up after the process got underway can now get “back issues” of the previously released rewards packages. A catalog of more than the first years worth has just been posted; each month will see an updated catalog posted for Patrons to order from. So if you are interested, check out the APR Patreon page to see how to sign up; if you are already a patron, check out the catalog here.

 Posted by at 3:41 pm
Sep 122016
 

Jeff Bezos of Blue Origin has described a new rocket his company is working on , the “New Glenn.” It’s kinda big:

new-glenn-large2

The “New Glenn” will be 27 feet in diameter (close to the Shuttle External Tank, it seems), 270 feet tall in a two-stage configuration and 313 feet tall in a three stage configuration. The first stage is recoverable, landing vertically under rocket power. It will have seven BE-4 engines burning natural gas and oxygen, producing 3.85 million pounds of thrust. The second stage uses a single BE-4 engine with an increased expansion ratio. The third stage uses a LOX/LH2 BE-3 engine.

The article says that Bezos has claimed that the rocket will fly “within the decade.” If that means by the end of 2019, that’s pretty ambitious.

 Posted by at 9:58 pm
Aug 212016
 

The Ryan XV-5A Vertifan was a 1960’s VTOL aircraft that was given considerable testing and proved to be reasonably successful, yet it was not chosen to be put into production. he video below (a couple different versions of it) show the XV-5A being put through its paces. It’s shown to be a remarkably nimble and stable platform. Also shown are numerous pieces of concept art, the XV-5A being used in a rescue capacity. Interestingly, the idea presented was to send the VTOL right alongside strike aircraft so that it would be right there on the scene ready to collect any pilots who happen to get shot down during the mission.

The XV-5A used largish fans embedded win the nose and wings to provide vertical thrust; the fans were driven by the exhaust from the jet engines. This is not a particularly elegant solution, unlike the Harrier with its fully integrated single engine system, but the fan approach would provide both better fuel efficiency during hover and lower jet velocity compared to something like the Harrier or the F-35. This would mean that the vertical thrust would tear up the dirt or deck plating a whole lot less.

One wonders how well the XV-5A would perform today. It would have the benefit of better engines and better materials, meaning more thrust at lower fuel consumption, in an aircraft that weighs less. And perhaps more importantly, modern avionics and computerized controls would make this plane much more stable, controllable and safe in hover.

 

 

 

 Posted by at 9:09 pm
Jun 252016
 

A heavily illustrated USAF brochure on turbine engine technology included, among a vast number of little photos of engines and aircraft, a few illustrations that might be of interest.

Several futuristic concepts here, several old ones. Of particular interest is the “Supersonic Multirole Fighter,” which looks like a cross between the old Lockheed Hopeless Diamond concept and the Northrop XST design… tailless with an inlet on top, with features reminiscent of the F-117, but blended rather than faceted.

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Of these “Emerging Concept Needs,” several are distinctly old. The middle row of three designs are all 20+ year-old concepts.

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 Posted by at 6:08 pm