Armstrong Whitworth AW.681 / HS.681

Thanks for the info. I think I have seen some of those images before, but assumed they were AW681 as they are quite similar. The only 129 I could think of was the current helo (The AW suffice on the helicopters does keep causing me some confusion, I automatically think of Armstrong Whitworth not Augusta Westland).

Thanks and regards.
 
C-130H and C.160 Transall could do much of HS681/NBMR.4's job. Cost/complexity would dish all these 1959-65 V/STOL schemes, except only the Gutersloh Wing of Harrier GR.1. That was assigned a very precise Task of scattering Red armour, for which dispersed operation was vital. When funded, 2/65, the assumption was that the Improved Kiloton Weapon - quite a small Bang, guv, honest, not to provoke escalation - could be used. (to be) WE177A was British, I tell you, so could be deployed by UK PM. What dished all the NBMR.3 V/STOL strike schemes was that US dual key stores were controlled at Main Base by USAF "custodials", who could not disperse. So no point in buying V/STOL cost/complexity (conscript ground crew) only to toss HE on Ivan.

FRG persevered longer with hi-tech V/STOL strike, AVS enduring into early-1968. NATO then concluded that long runways would remain available through "flexible" HE phase of conflict, and would still be there to launch the one-sortie nuke phase. So, Tornado, F-15/16/18, Mirages, OK. No need to scorch and rut meadows, trying to replenish hidden hoppers.
 
alertken said:
...FRG persevered longer with hi-tech V/STOL strike, ....
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Indeed, and often design points points were quite different. Just compare the Harrier
(true V/STOL) to the VAK 191. But if you read contemporary German military publications,
the feeling, not to live at the front, but actually being the front, with no area to retreat to,
had sunk in. If you look at those internal mags, made on squadron level, with reports about
the last summer fair, the 20th jubilee of the squadron commander and the like (had or have
a some of them from a flea market), you can find articles as well, stating that the German
airforce would have to fight a kind of "aerial guerilla warfare", with true VTOL being absolutely
mandatory.
 
alertken said:
except only the Gutersloh Wing of Harrier GR.1. That was assigned a very precise Task of scattering Red armour, for which dispersed operation was vital.
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According to the Crossman diaries those RAF Harriers were a political not a military decision- work had to be found for Hawker Siddeley after the cancellation of the 681 and P.1154 and the P.1127 was it. Apparently funded outside the normal defence budget too as the RAF didn't want it.
 
Tks Jem: my approach to History, and especially to Why did they do that?, is to assume sanity - it seemed a good idea at the time - and to try to put myself in the boots of the mover and shaker. So, for example: why did USSR put IRBMs in Cuba, 1962? Well, take a globe and turn it so that Siberia is at the top. Now mark US/NATO nuke sites, such as Jupiter/Turkey. All then becomes clear. We, here (Euro-centric) can fall into the trap of believing the earth spins on a DC/London axis.
 
The illustration shows the early pre launch 681 arrangement as it has 4 wheel MLG's. Shortly after the 681 contract was placed it changed to a "3 wheels in a line" arrangement. A bit like the C130 but with an extra wheel, but on 681 each one of the 3 Landing Gears retracted forward as opposed to C130 straight upward raise.



I managed to have a good look into the surviving 681 files a good few years ago. They included a few photo's of actual first Aircraft detail parts in manufacture. It was sad reading the memo's written in the last few months of the project, as many related to key members of the development staff leaving and the inability to replace them.



C130 main problem is it bulks out before it loads out;- i.e. it could uplift more landies than it can be actually loaded because you can only fit a single row of them in the Fuselage. Fairly early in the 1960's it was realised that with a re-optimised fuselage diameter it was possible to ship more load (i.e. two rows) with fewer flights. This was the principle of 681/->/A400M
 
Thanks Overscan
I didn't know that the 681 project got as far as mock-up!
A sad opertunity and capability missed by the Brit's, something they would not make up for for decades to come in the form of the American C-17 :-[
Also just noticed on your posted 'Vertical Airlift' (page 8) the notion that the 681 could airlift a Centurian MBT! Interesting ..... and again a sad opertunity missed :mad:

Regards
Pioneer
 
PaulMM (Overscan) said:
If you want to know more about the AW.681 / HS.681 I recommend Mike Pryce's 8 page article in Air Enthusiast July/August 2006. Low res scans attached.
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How would one go about acquiring a copy of this article? The magazine has been defunct for years, and its publisher (Key Publishing) doesn't offer back issues on their website.
 
Hi Hobbes,


I get later a version of that issue,I can send it to you.
 
AW.681 model at Cosford 2013 courtesy of forum member Hobbes.
 

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Here is an undated British Movietone newsreel (silent) footage showing a couple variants of the Armstrong Whitworth AW.681 in model form.
YouTube - British Movietone - "NEW PLANE - NO SOUND"
Caption: "Model of AW681. Engine nozzles. Movement capability. Air-blown flaps. Rear doors open for air dropping and ground loading. Undercarriage etc. Take off aspects."
(VIDEO CLIP REPLACED - SEE EDIT BELOW)
EDIT: Better yet, here is the clip with sound narration and the title "Towards The Vertical":
http://www.youtube.com/watch?v=QK2_asiNk4Y&t=1s
 
In those first two pictures AW 681 looks almost balanced (Center of powered lift close to centre of gravity) with Medway engines and pivoting rear nozzles.
OTOH The Pegasus-engined version has engines way too far forward to balance.

On the subject of Lockheed C-130s bulking-out long before they reach gross weight: Lockheed has built a bunch of stretched C-130s to increase cabin volume. Stretched C-130s can be identified by side doors that are still near the wing trailing edge, but well forward of the tail ramp.
 
Hi!
Three-view of the Bristol Siddeley Pegasus 5/6A-powered version of the AW.681 of 1963 with modified twin-nozzle engines.

This Pegasus engine has a different shape compared with my image for Pegaus.
www.si.edu

Bristol-Siddeley Pegasus Mk. 5 Turbofan Engine | Smithsonian Institution

www.si.edu www.si.edu
Page 163.
books.google.co.jp

Pegasus, The Heart of the Harrier

The conception of the Pegasus engine in 1957 upset all the conventions of aircraft design. It was previously usual for aircraft designers to seek a suitable engine, but this was an engine that sought an aircraft. The aircraft that resulted was the famous Harrier that is still in front-line...
books.google.co.jp
I can't understand how to work this engine.

15-2.jpg
 
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Artist's impression of the definitive version of the HS.681 unloading Saladin armoured cars in the Middle East, with another aircraft overhead carrying out a short landing using deflected thrust. (thrust line are 8.) Vertical?
12-1.jpg
 
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The Armstrong Whitworth AW681 briefly challenged as an STOL military transport product but the project was cancelled in February of 1965.

Armstrong Whitworth AW.681 Four-Engined STOL Transport Aircraft

Page details technical specifications, development, and operational history of the Armstrong Whitworth AW.681 Four-Engined STOL Transport Aircraft including pictures.
www.militaryfactory.com
 
I still find the 681 confusing even after Michael Pryce's excellent article. Russia and Japan both built excellent superficially similar airlifters in the 60s but without the stovl nonsense. Replace the Medway deflected with a straightforward jet engine like a C141 and the 681 was perfectly affordable. And I mean the podded one not the hideous Comet wing job.
Of course with the C130 still in service and the US YC14/15 also stillborn I am probably wrong
 
Wikipedia says that
"One envisioned variant of the AW.681 would have been capable of VTOL performance as well, albeit requiring extensive alterations in order to achieve this. In one configuration, it would have been powered by an additional eighteen 6,000 pound-force (27,000N) RB.162-64 lift engines in addition to its four Medway engines. Alternatively, the Medway engines could have been replaced by fourBristol Siddeley Pegasus ducted-flow turbofan engines, the same power plant as used on the Harrier Jump jet. The specific version of the Pegasus projected for use was 5 or 6, which would have been rated at around 18,000 pounds-force (80,000 N). Both approaches were proposed as being capable of obtaining a realistic VTOL capability."

AW.681 gross weight was around 80ton.
RB.162 thrust was around 2.72ton, Medway thrust was around 6.2ton. 2.72×18+6.2×4=73.76ton
So perhaps it's possible to take off vertically when small payload condition. I recommend STOVL.
Anyway it's impossible to take off and landing vertically with only four Pegasus engines.
 
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uk 75 said:
I still find the 681 confusing even after Michael Pryce's excellent article. Russia and Japan both built excellent superficially similar airlifters in the 60s but without the stovl nonsense. Replace the Medway deflected with a straightforward jet engine like a C141 and the 681 was perfectly affordable. And I mean the podded one not the hideous Comet wing job.
Of course with the C130 still in service and the US YC14/15 also stillborn I am probably wrong
Click to expand...

The basic problem with the C130 is that it bulks out before it loads out. In simple terms the fuselage diameter is just a little too small;- example- although it can easily lift eight Land Rovers, they’re 10 inches too wide to park side by side on the cargo deck so you can only get four in. Lockheed attempts to fix this have focused on stretching the fuselage, which although it improves the amount lifted it still inefficient in terms of range and operating costs.

There’s been, indeed still are, a few attempts offer better solutions, in particular a slightly wider fuselage, but the C130 is still the lowest cost, most proven, most reliable, most easy to support solution out there. Also this part of the market is more akin to trucks, where companies such as Ferrari won’t ever do well.
 
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Foｒ example, you can use this plane to land on the aircraft carrier, unload your luggage, then lift off vertically in a lightweight state, and then refuel the plane with enough fuel by air refueling. At first you take off normally.
 
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First set of shots, #109, are from the Avro Museum at Woodford... I suspect the models presence is from the Woodford design teams development of the aircraft as the HS802 which saw the aircraft fitted with Comet/Nimrod wing/engines...

Some interesting discussion on the design can be found in Hansard for 9th Feb 1965

Second set, #111, are from the Midland Air Museum...

Zeb
 
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Chris On Atlas' Shoulders is an essential work on Airlifters but I recall you use Michael Pryce as a reference.
Surely you agree thst a UK Il76 could have been built if everyone involved haf been more realistic.
 
This model shows AW.682 a civil freighter version of the 681 with lengthened fuselage(37.5m) and four Pegasus without vectored thrust.(Derek Wood, PROJECT CANCELLED)
26727353564_93017ac242_b.jpg 27237206102_21d665b402_b.jpg
 
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Zoo Tycoon said:
uk 75 said:
I still find the 681 confusing even after Michael Pryce's excellent article. Russia and Japan both built excellent superficially similar airlifters in the 60s but without the stovl nonsense. Replace the Medway deflected with a straightforward jet engine like a C141 and the 681 was perfectly affordable. And I mean the podded one not the hideous Comet wing job.
Of course with the C130 still in service and the US YC14/15 also stillborn I am probably wrong
Click to expand...

The basic problem with the C130 is that it bulks out before it loads out. In simple terms the fuselage diameter is just a little too small;- example- although it can easily lift eight Land Rovers, they’re 10 inches too wide to park side by side on the cargo deck so you can only get four in. Lockheed attempts to fix this have focused on stretching the fuselage, which although it improves the amount lifted it still inefficient in terms of range and operating costs.
Click to expand...
Exactly as the USAF did with their Lockheed C-141B...

Regards
Pioneer
 
A few years ago I had to design some mine/oil field equipment that was to be transported by civvie C-130's. I was told that the absolute maximum width I could have was 10'-0". even 1/8" wider would mean the company would have to wait till winter and then transport it up the Ice Road.
 

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