In the late 1950s/early 1960’s, a number of manufacturers produced designs for “flying jeeps.” In general these were effectively small open-cockpit helicopters with two small rotors, one fore, one aft. While some flew, none flew well enough to merit production. They had the noise and slow speed of helicopters, but due to the small diameter rotors and consequent high disk loading, they did not have the hovering performance of helicopters. Additionally, the flying jeeps tended to have some impressive stability issues.
One unbuilt design was the one below, by Kellett. It was a basically stereotypical flying jeep, having fore and aft low-mounted rotors attached to a central automobile-like pod. Note that due to the low mounting of the rotors, an extensive and rather tall support structure and landing gear system was required. It would seem to me that it would have been better to skip a few steps and go ahead and mount the rotors above the fuselage.
With modern materials, control systems and turbine engines, the functional but impractical designs of the 1960’s might be somewhat more servicable today. For instance, they’d seem to make decent air taxies… perhaps to modern lighter than air flying aircraft carriers.
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Here we go again
http://tinyurl.com/27twsb4
Such craft, despite their limitations, might have one real advantage and that would be landing on cramped landing pads on small ships. They wouldn’t need as much space for rotor clearance and landing might be more forgiving if the rotors were fully shrouded.
This might make practical S.A.R. and limited utility aircraft operations off a vessel like the Aussies Armidale class that can now only operate small UAVs if anything.
Regarding the DARPA one, it looks like it has surplus F-111 wings on it.
At least that’s better than the Kellet design; the problem any of the ducted rotor concepts had, right down to the little flying platform, is that they don’t look like they can autorotate down in an emergency like a helicopter can.
The closest thing I ever saw to a flying jeep is the little Hughes Cayuse; a really superb job of packaging four guys into a minimal sized helicopter, that’s really pretty quiet as well.
[…] from the early 1960s, using four apparently fixed lift ducts. It would have performed much like the air jeeps, just on a larger […]
Meanwhile, back at the atomic-powered flying aircraft carriers, they use helicopters:
http://blog.modernmechanix.com/2008/03/22/why-dont-we-build-an-atoms-for-peace-dirigible/
People who design things like that always grossly overestimate how much of the hull’s interior can be devoted to payload and living quarters rather than gasbags.
By the time you get enough shielding on the reactor to make it safe, you will lucky to carry just it aloft with nothing else aboard.
The whole concept resembles that of the Soviet “Maksim Gorki” giant propaganda aircraft. Maybe it could have projected images of Eisenhower down on the top of thin clouds like that plane could send down images of Stalin, while his voice boomed out of giant loudspeakers on its bottom.
If that wouldn’t scare the piss out of you, nothing would. 😀
Wikipedia cites the 6.5 million cubic foot Akron as having a useful load of 83 tons, and a “tonnage” (dead weight?) of 100. Tinsley was an artist, not an engineer, but I seem to recall the atomic powered “flying hotel” design of 1968 or thereabouts as having a useful lift of 150 tons, of which total the reactor and shielding left sufficient capacity for 100 passengers (as vs. Akron’s complement of 89)…which seems “back of the envelope,” not unreasonable, given that the Convair X-6’s 3 megawatt test-reactor-in-flight called for a mere 12 tons of shielding.
Mind you, I’m standing mute on the concept of an atomic powered dirigible as…how to put it…”not unsettling” even today, let alone in Ike’s day. But I don’t think it’s necessarily technically infeasible.
Look at the cutaway of the interior of the Hindenburg and how much of its interior volume is the passenger and crew area in comparison to the “Atoms For Peace” one:
http://www.flightglobal.com/imagearchive/Image.aspx?GalleryName=Cutaways/Airships%20and%20Hovercraft/Airships&Image=LZ-129-Hindenburg
You could improve things nowadays by replacing the metal frame with composite materials, and making the gasbags out of high strengh plastic, but at the time the AFP one was proposed, those were still in the future.
Another oddity in the design is the nose radar in its transparent housing; not only is there no reason to make the radome transparent, but the radar dish seems way too big to just be used for weather avoidance.
Apparently the flight deck crew looks out through the lower radome to see forward, even though they could have been housed at the front end of either the upper or lower air conditioning duct intakes (as to why it needs that much air coming into it is a good question; the passengers must constantly smoke, and the airship leaves a cloud of tobacco smoke behind it as it flies.
One thing that does show up in that illustration is the constant desire to get passengers up on top of the airship rather than hanging under it. That was also a feature of the proposed Vickers Transoceanic Airship design, which is available as a free paper model download here:
http://www.currell.net/models/vickers.htm
More info on it here: http://www.aht.ndirect.co.uk/airships/vickers/Trans%20-Oceanic.htm
….though one wonders if putting that much weight on top of the dirigible will make it capsize.
Vickers – for all your airship needs:
http://homepage.ntlworld.com/forgottenfutures/vickers/vickers.htm
That’s right out of Kipling’s “With The Night Mail”. 🙂