H-4 Hercules "Spruce Goose"

I never did give it much thought before, but I read up on the H-4 Hercules "Spruce Goose". It truely is a massive aircraft. I never did realize its size and capabilities until recently.




"In 1942, the U.S. Department of War was faced with the need to transport war material and personnel to Britain. Allied shipping in the Atlantic Ocean was suffering heavy losses to German U-boats, so a requirement was issued for an aircraft that could cross the Atlantic with a large payload."

Link 1

"Better known as the "Spruce Goose," the Howard Hughes Flying Boat was designed and built by Hughes Aircraft Co., to be the largest wood constructed aircraft with the largest wingspan ever built. As Hughes perfected his craft, he added significantly to what is known in areas of large-lift capability and power-boost systems. Originally designated the HK-1 in 1942, it was designed to meet wartime troop and material transportation needs (flying just high enough to evade submarine attacks). Laminated wood (mostly birch) forms the airframe and surface structures of the seaplane, minimizing the use of critical war materials like aluminium. It was powered by eight ."

Link 2

It really is an amazing aircraft, I guess size doesn't matter when it comes to flying. I wonder, what current modern influence has the H-4(Originally HK-1) had on aircraft? Surely for an aircraft of this magnitude, it has to have had an impact on large transport aircraft.

Shattered OUT...

It was indeed absolutely immense, but I'm not sure what you mean about its 'capabilities'?

It only left the water once and even then only raised itself a few feet from the surface, hardly an indication of any capabilities.

If you are interested in other very large aircraft I also suggest you look into the Bristol Brabazon, Saro Princess and Convair XC-99, all dating from around the time of the Spruce Goose and all just as massive and unsuccessful.

By "capabilities" I mean 400,000 pound cargo load. Now, if that's not a capability, I don't know what is.

Shattered OUT...

Originally posted by ShatteredSkies
By "capabilities" I mean 400,000 pound cargo load. Now, if that's not a capability, I don't know what is.

Shattered OUT...

If it could lift that I would agree, however, as I have already stated, it was barely capable of lifting itself off the water.

The three other aircraft I listed for you did all actually fly properly, but they too were impractical. The problem wasn't the design of the aircraft itself, but merely the inadequacy of engine technology at the time.

thisis the one and only flight of the H-4 and it is also as high as it ever got, alas.


[edit on 5-10-2005 by waynos]

If you are interested in other very large aircraft I also suggest you look into the Bristol Brabazon, Saro Princess and Convair XC-99, all dating from around the time of the Spruce Goose and all just as massive and unsuccessful.

massive, yes. unsuccessful? only if you call projects like the x1 or the x15 unsuccessful. the spruce goose pioneered technologies that are still used today (hydraulics for instance), and it proved that a large heavy lifter aircraft not only could be built (something thought to be impossible at the time), but with the development of better engines and building materials, would completely change the way the US military does business. thanks to technology pioneered by hughes, we can now send whole divisions of troops with equipment to hot spots in literally hours instead of weeks.

[edit on 5-10-2005 by snafu7700]

The first flight of the aircraft was not a testing of the what the aircraft was completely capable, Hughes' Engineering chief advised Hughes not to go to the limits of the aircraft, and Hughes was not about to risk the lives of the people on board the aircraft, so all he did was lifted the aircraft off the ground, it was just a vindicatory flight, it was to prove everyone that doubted him wrong, in no way shape or form was a it a true test of the aircraft.

Hughes never did test the aircraft completely, that was its only flight, the aircraft was thought by Hughes to be capable of cruising at an average speed of 200 mph, and at an altitude of 6000-7000 feet.

If only the aircraft was fully tested. Imagine if it would have been mass produced, but the fact remains, it was never mass produced, that the government no longer needed the aircraft, so Hughes basically put his own money into funding it, it was no longer held by the government, it was Hughes' own problem now.

Shattered OUT...

reply to snafu;

massive, yes. unsuccessful? only if you call projects like the x1 or the x15 unsuccessful.

Not at all, the X-1 was intended to explore speeds in excess of mach 1 - mission accomplished.

The X-15 was intended to explore hypersonic flight on the boundary of space - mission accomplished.

Both these programmes werre entirely successful. The only way you can call the Spruce Goose a success was if the point of the programme was to build a single, huge flying boat in order to skim along a few feet off the surface of the river - was it? I don't think it was.

the spruce goose pioneered technologies that are still used today (hydraulics for instance),

Sorry, that is total cobblers, hydraulics were in common use a VERY long time before the Spruce Goose was built, also it was a huge, hollow WOODEN structure, how many modern large transports follow this pattern?

it proved that a large heavy lifter aircraft not only could be built (something thought to be impossible at the time), but with the development of better engines and building materials, would completely change the way the US military does business.

Wrong again, the Germans had proven the viability of very large transports in WW2, although vulnerable and cumbersome they were actually used operationally, something the Spruce Goose never was.

Also the "development of better engines" was exactly my point in my previous post! ALL these large aircraft failed because engine technology simply wasn't up to the task - end of story.

to Shattered Skies;

Hughes never did test the aircraft completely, that was its only flight, the aircraft was thought by Hughes to be capable of cruising at an average speed of 200 mph, and at an altitude of 6000-7000 feet.

EXACTLY! For all anyone knows the structure may not have stood up to the stressess of fully laden flight. It may have been fine but any claims as to performance and capability can be nothing but projections and conjecture. The FACT is that it never did anything more than a short hop. For all anyone knows it might have simply broken up with the stresses placed on those huge wooden spars. But like I said, it might have worked perfectly with more powerful engines, we will never know. Thats why I pulled you up on your claim about its wonderful capabilities. There could easily be a world of difference between what it was intended to do and what it acvtually could do.

Why do you think there were NO successful giants before the 747? I'll say it again ENGINES!

If you are still marvelling at the 'pioneering technology' (lol) let me quote you a few sentnces from "The Worlds Worst Aircraft" by Bill Yenne (a book featuring many different types, not just the H-4);

Hughes had a 200 ton Albatross around his neck, with little idea what to do with it....

The H-4 was a remarkable novelty, but it was little more than this and a monument to obsolete technology. It was conceived at a time when such gargantuan vehicles were seen as the wave of the future but by the time it flew the idea was already a thing of the past

Nowhere in the chapter does it mention anything of the H-4 heralding one single thing that was of use to future generations.

The idea of it proving large aircraft were possible is nonsense, building ever larger aircraft was always the ambition of aircraft makers ever since the Sikorsky Le Grand of 1912 became the first four engined aeroplane to fly, it was always the power of the available engines that was the limiting factor.

Look at todays A380, it is only feasible because of the availability of engines such as the Trent 900 which allow it to be a four engined type. The same design in the 1950's would have required maybe ten Conways and been a preposterous idea, witness the Saro P.92 project, a serious study for a 1,000 passenger 24-Conway powered flying boat for P&O - a ludicrous idea because of the engine (and structures) tech of the day but one which may yet be surpassed by a stretched A380 if the demandfor it ever arose.

That is not to say that the imagination and audacity that led to the creation of the H-4, Brabazon, Princess et al shouldn't be admired, or that the aeroplanes themselves shouldn't be admired for the engineering marvels that they were. I adore all of these aircraft but my favourite one is the Brabazon, even though it was no less misguided and useless than the rest of them, I just like it very much. But we have to avoid ascribing abilities and acheivements to such aircraft that are simply not true.




[edit on 5-10-2005 by waynos]

Waynos,

Im thinking that the stresses placed on the airframe, mainly the fuselage, during the takeoff stage would dominate any other stresses during flight since it was a water-borne craft. The forces of the water on that hull when taking off must have far surpassed any wind driven effects during flight. I seem to have this belief in my head that there is more stress on the wings at takeoff than at any other point in flight, maybe im way wrong, correct me if i am.

Its not as if this plane was pulling 5 g banked turns either, one purpose, heavy lift. Lets not forget, Howard Huiges did not design this aircraft, he mearly financed it with his company and he hired the worlds top engineers. This plane would have done exactly what it was designed to do, getting out of the water with those weak motors and 200 tons of cargo is something else entirely. Perhaps possible if ground based takeoff, not water.

You're right Waynos, the H-4 was never tested to its full capacity. But now, if Hughes himself, knew that Engines was an issue to be addressed(Which he did address it by putting 8 of the world's most powerful prop engines at the time on the airplane), then why did for 30 years he keep it in flying condition? Up until the day he died, it was kept in flying conditon, but never flew, that was a pot load of his own money that went to maintaining a dead aircraft. Now, safe to say he was eccentric and did go crazy for a while, but he's an intelligent man, even he would have realized that the engines available just weren't powerful enough, they only put out 24,000 lbs of thrust total(which each F-119 Pratt and Witney Engines puts out, the same ones on the F/A-22 Raptor).

I'm sure he knew it could fly and do what he wanted it to do, as it was said, this is a man that doesn't know how to fail, he spent 14 million of his own dollars trying to build this aircraft. He even said that if he did not complete the aircraft, he would leave the country, that's how set on it he was.

And the H-4 did inspire future large cargo vessels. Now that engine technology has taken a quantum lead(thanks to turbojets) forward, large aircraft such as the C-5, An-225, A380, 747-400, are all able to fly. Also the aircraft was a marvel because it was one of the first aircraft(of it's size) to be used of composite materials. Yes it had its critizisms, but it's still a marvelous aircraft nonetheless, I don't think anyone can look at it and not be awestruck by the sheer size of it, and the fact that it actually flew(even though it was for 1 mile and less than 50 feet off the water) with WWII era engines.

It also had advanced Hydraulics systems, which was one of the reasons why it was illegal to fly the aircraft the day Hughes took it out to taxi in the Long Beach area in South California.

Now true, most of the complications did rely on hydraulics and engine power, but it still flew nonetheless, give Hughes credit for that.

Shattered OUT...

Well firstly, whilst ever in contact with the ground (or water) the whole aircrafts weight is supported by it, the proportion of weight supported by the wings gradually increasing as take off speed is approached, only when it becomes fully airborne do the wing spars have to support the entire weight. It is at this point wing stress is at its highest (barring manouvres as you say)

Don't forget that the aircraft was not designed to be made of wood in the first place. It was only when Hughes was refused permission to obtain 'strategic materials' ie alloy, that wood (birch, not spruce) was substituted in order to allow a prototype to be built. Although (as proven) it was perfectly possible to build it out of wood this would have had a dramatic effect on the structural strength and weight of it overall.

Also, having a properly stressed hull does not indicate strength anywhere else. Saro's rival to the Sunderland, the A33, was canned when the main wing spar failed on the take off run for what would have been its fifth flight. The hull was utterly sound. My point here merely being that one hop does not demonstrate the soundness of any aircrafts structure. Many aircraft have suffered structural failure and all of them designed by highly qualified and experienced engineers. The problem you face when you are pushing back boundaries (as the H-4 did by dint of its sheer size) is that you don't know what you are up against until you try.

I am not saying the structure of the H-4 would have failed, how could I know that? Only that Shattered Skies claims of great payloads and ranges are baseless as such ability was never demonstrated. Any study of Aviation history will demonstrate the huge differences that often applied between what a designer said his aeroplane would do and what it was eventually seen to do.

Also, Hughes did not merely finance the project (and he 'only' financed about 1/3 of the cost) but it was he who conceived the very idea in the first place. He was a very hands on chap and although he did have designers, he himself was also very involved in the whole process.

Originally posted by ShatteredSkies
You're right Waynos, the H-4 was never tested to its full capacity. But now, if Hughes himself, knew that Engines was an issue to be addressed(Which he did address it by putting 8 of the world's most powerful prop engines at the time on the airplane), then why did for 30 years he keep it in flying condition? Up until the day he died, it was kept in flying conditon, but never flew, that was a pot load of his own money that went to maintaining a dead aircraft. Now, safe to say he was eccentric and did go crazy for a while, but he's an intelligent man, even he would have realized that the engines available just weren't powerful enough, they only put out 24,000 lbs of thrust total(which each F-119 Pratt and Witney Engines puts out, the same ones on the F/A-22 Raptor).

It was a real labour of love for him, to be sure, and he clearly became utterly obseessed with it. to try and read rational reasons into why it was so lovingly maintained for so long is a mistake, you have to understand the state of his mind after his traumatic experiences after the war and just what it had cost him (emotionally more than fiancially) to get his big boat built at all.

I'm sure he knew it could fly and do what he wanted it to do, as it was said, this is a man that doesn't know how to fail, he spent 14 million of his own dollars trying to build this aircraft. He even said that if he did not complete the aircraft, he would leave the country, that's how set on it he was.

like I just said....

And the H-4 did inspire future large cargo vessels. Now that engine technology has taken a quantum lead(thanks to turbojets) forward, large aircraft such as the C-5, An-225, A380, 747-400, are all able to fly.

Not one of the aircraft you named owes one iota of their technology to the H-4, like I said aircraft designers have always sought to go farther, faster, higher and bigger, to ascribe the existance of any of these aircraft to the H-4 is fantasy.

Also the aircraft was a marvel because it was one of the first aircraft(of it's size) to be used of composite materials.

The composites of the 1940's had nothing to do with the composites we think of today. Whilst 'composite structures' today refers to various plastic based compounds don't be fooled into thinking this was the same. In the 1940's 'composite' merely meant 'made up of different materials', for example the DH Mosquito's balsa and plywood sandwich construction was a 'composite structure'. This is what is meant by the term in relation to the H-4. It is not the start of todays composites by any stretch of the imagination.

Yes it had its critizisms, but it's still a marvelous aircraft nonetheless, I don't think anyone can look at it and not be awestruck by the sheer size of it, and the fact that it actually flew(even though it was for 1 mile and less than 50 feet off the water) with WWII era engines.

Now here I can agree with you 100%. It was an awesome machine, I just think you are getting a bit carried away with your ideas of what it was and what it could do.

Now true, most of the complications did rely on hydraulics and engine power, but it still flew nonetheless, give Hughes credit for that.

Shattered OUT...

Why the defensiveness? I am not here to bash the H-4, getting it intro the air was a fantastic acheivement, but that does not mean you have to turn it into a global wonderplane or the father of the 747 for it to be impressive. I have studied avaition for over thirty years, in great detail, the history of great aircraft of the past is my speciality, whereas you may be able to tell me much more than I know about current developments. I am interested only in helping you to understand the reality of the situation as far as these great aeroplanes of the past are concerned.

As great as it was, and I admnit it was, it is a fact that it WAS underpowered, it WAS impractical, and producing it at all was an act of sheer folly.

But this also applies to all the other early giants I have named and they were all wonderful and I love them! Can you understand my point of view?

As a final side note. I wonder if you realised that to call the H-4 'Spruce Goose' in earshot of Howard Hughes would have most likely earned you a smack in the gob? He detested the name, which was a derogatory nickname coined by the press.

[edit on 5-10-2005 by waynos]

I'm aware that the name "Spruce Goose" was given to the aircraft to try and get people against it, such as one of the senators called it a "Flying Lumberyard". I know that Hughes detested the name "Spruce Goose", but we already have a "Hercules" in the Transport inventory, the C-130.

I don't know, when I saw Man, Moment, and Machine, they spoke of how even thought no direct connection is made to modern era transport craft, the H-4 does still have its routes in massive transport aircraft of today, it was inspiration for other engineers of the future to buiild large aircraft, the fact remains, that it demonstrated, when it comes to flying, size doesn't matter, you can make it as big as you want, but as long as it has the right power, it can fly.

I think the full cost of the aircaft to build in 1942-1947 was 22 million dollars, he spent 14 million, how is that 1/3 of the cost?

Shattered OUT...

from this site:

sres.anu.edu.au...

The Goose’s entire airframe and surface structures are composed of laminated wood, almost entirely birch, and are almost entirely devoid of nails and screws. The ‘Duramold’ process used to form each component of the plane uses layers of 1/32 inch wood veneer. Layers are arranged with their grain running perpendicular to that of their neighbours, bonded with special glues, and shaped with steam. The end product is a material of amazing lightness and strength.

from merriam webster:
Main Entry: 2composite
Function: noun
1 : something composite : COMPOUND
2 : a composite plant
3 : COMPOSITE FUNCTION
4 : a solid material which is composed of two or more substances having different physical characteristics and in which each substance retains its identity while contributing desirable properties to the whole; especially : a structural material made of plastic within which a fibrous material (as silicon carbide) is embedded

yeah, thats wood, but its still composite.

Dismissed as impossible even by many of Hughes’ colleagues, and dubbed ‘the flying lumberyard’ by a disgruntled US senator, the Spruce Goose was decades ahead of its time. Its development shaped modern flight, solving tremendous design and engineering problems, testing new concepts for large-scale hulls and flying control surfaces, and revolutionising jumbo flying bodies and large lift capability. The cargo planes of today bear the Spruce Goose a striking resemblance in some important ways.

hmmm.

Sorry, that is total cobblers, hydraulics were in common use a VERY long time before the Spruce Goose was built, also it was a huge, hollow WOODEN structure, how many modern large transports follow this pattern?

really. exactly which aircraft prior to 1947 depended upon hydraulics to fly?

and has already been pointed out, the aircraft design was not intended to be wooden...it was the only thing available at the time do to the war.

oh, and lets not forget that its STILL the largest aircraft ever to fly....and it did it with 1940's technology.

Specifications

DIMENSIONS



Wingspan
320 ft
96.9 m

Tailspan
113.5 ft
34.4 m

Vertical Tailspan
49.5 ft
15 m

Hull Length
219 ft
66.4 m

Hull Width
25 ft
7.6 m

Hull Height
30 ft
9.1 m

Overall Height
79 ft
24 m

Gross Weight
300,000 lbs
136 200 kg

Wing Area
11,430 sq. ft.
1050 sq. m

Max. Wing Thickness
11.5 ft
3.5 m

Payload
130,000 lbs
59 020 kg

Fuel Capacity
14,000 gallons
56 000 L

Power
24,000 hp

Shattered, you said yourself "even though no direct connection is made to modern era transport craft". That distinction of "direct" is crucial to the argument. It is what I have said all along.

The size of the thing was inspirational, but no more or less than EVERY giant aircraft going back to the the Handley Page V/1500 or the US Barling Bomber through types such as the Dornier DoX, Messerschmitt Me 323, the list goes on. The H-4 is one of a long line of 'biggest planes in the world', each one driven by the last and the percieved global needs of their designers. The one thing they all have in common is that until the 1960's they were all years ahead of the available power the engine industry could give them. Its not as if nobody tried, or succeeded, to build the worlds biggest plane before the H-4 and then everyone tried after it, which is what this thread appears to be making out.
It is one of a long line.

According to my source the cost was $14m to Hughes and a further $22m to the US taxpayer, hence my rough estimate of it being 1/3 of the cost.

Put another way, and in a direct quote, it puts the aircrafts first flight into financial perspective thus;

She had cost Howard Hughes $117,000 for each second she was in the air and she had cost the American taxpayers $300,000for each of those seconds

Again, roughly speaking, Hughes stumped up 1/3 of the cost.

Snafu,

yeah, thats wood, but its still composite

Isn't that exactly what I said? re my comments about the DH Mosquito's identical composite structure (just as described in your own quote for the H-4 structure). This does not contradict what I said about how what we understand by the term 'composite' in relation to aircraft construction has changed over the years. When people say that the F/-22 has composite structures on board do you assume they mean plastic based, or wood? That is all I am saying.

Your second quote, about modern large transports resembling the H-4 would appear to be someones opinion, rather than fact. Could you enlighten me as to what features of the H-4 carry over to any modern large transport. If you can I will admit defeat in this area, I am simply unaware of any such feature.

Which aircraft depended on hydraulics to fly?

Well, it has been my understanding for many years, and via various sources, that the first aircraft to fly with fully powered hydraulic controls without manual reversion was the Bristol Brabazon, then the biggest landplane ever attempted and slightly bigger than the B-36, whereas the H-4 had hydraulically assisted manual controls, such has had been used on some large aircraft during the war, albeit on a vastly bigger scale in the H-4 naturally. Maybe you see this as splitting hairs but I think the distinction is an important one as fully powered controls are what abound today.

It is however, NOT still the largest aircraft ever to fly, nor would I expect it to be. It has the largest winspan ever flown at 320 ft, which is astonishingly big and fully 90ft more than the Brabazon, but the An-225 is the biggest aeroplane ever flown.

You might like these graphics I lifted from Aerospaceweb which help to illustrate just how big these planes were /are;





One thing I have never denied is that it is a mightily impressive aeroplane, the fact remains however that it was of no practical use.

Let me ask you, if it was so marvellously capable then why, with all the other giants appearing like the An-22 and with the advent of ever more powereful propeller tubines, was no attempt ever made to update or revive the project?

The answer is simply that nobody wanted big flying boats and that is why it languished in a shed of so many years, it managed to be far sighted and yet hopelessly stuck in the past at the same time, no mean feat. Here in the UK we did exactly the same thing, it was called the Saro Princess. The Princess is the second biggest flying boat ever built, after you know what, and it was powered by ten turbo-props from the start, it also actually flew beautifully and on many occasions but by 1950 flying boats were as hopelessly out of date as sailing ships. By coincidence the Princess was also kept in pristine condition for many years, but Saro gave up and scrapped it in 1967, by which time you would have hoped a preservation order would have been made on it but C'est la vie.

[edit on 6-10-2005 by waynos]

excellent follow up waynos....especially like the comparison charts.

yes, i think the major reason it was never pursued was the boat aspect of it. as you said, they were becoming out of date....even the navy was moving from the pbys to the land based maritime patrol aircraft.

but i still think this critter was a major contributor to the modern heavy lift aircraft. call it my opinion if you want, but the similarities in design (minus the wood contruction) between the goose and modern heavies are compelling.

We can always agree to differ on that final aspect, this has been a thoroughly enjoyable thread, thanks for the debate, all of you.

Here are a couple of pics of the Princess I have dug out which you might like for comparison. Each of the four pairs of contra props was driven by two coupled Proteus engines with the outer single props being driven by individual Proteus' engines, making ten in all. Despite the mechanical nightmare of this arrangement it might have given the Spruce goose the power it was otherwise lacking maybe? Not that it would have made any difference ultimately of course.

Link 3 with a lot of photos

That Heracles Concept for a new shuttle transport is really interesting, any follow-up on it? Or did they just convert an already built aircraft to transport the shuttle?

Shattered OUT...