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rcocean
02-13-2005, 10:28 AM
I know the Russians used wood in fighter construction but no one else did. Except the British for the Mosssie.

Given the success of the Mossie and LA-5, etc. could some expert tell me what, specifically, what was the big advantage of alumminium over wood?

Was it more difficult to use? Heavier? Less durable?

Any answers would be appreciated.

Lukki
02-13-2005, 10:37 AM
Bf-109G-6 late and up had a wooden tail unit I think. Not 100% sure but anyhow...

Another case that might not even exist if we had the object viewer near arming screen! Would educate people.

triggerhappyfin
02-13-2005, 10:42 AM
What about me-163 and the Lagg and Yak?

The Japanese used alot of wooden aircraft as well.

Akronnick
02-13-2005, 10:51 AM
The biggest advantage of metal over wood is that pound for pound, aluminum is stronger than wood. Usually when wood was used, it was a compromise because aluminum was not as available.

Jasko76
02-13-2005, 11:00 AM
Exactly. Russians didn't use wood because it was the preferred material, but simply a necessity as there was a shortage of strategic materials like alloys. As the war progressed less and less was used in Lavochkin fighters, culminating in La-9 which was an all metal fighter.

Mosquito is an exception to every rule...

Bull_dog_
02-13-2005, 11:16 AM
Another really good aspect of aluminum is that it...
1) Doesnt' splinter
2) Is easier to shape so load bearing members are more efficient for their weight
3) Aluminum doesn't absorb water or warp
4) Structurally speaking, an aluminum skin can and will bear load.
5) Wood is highly variable with regard to its structural, load bearing capability. This means one of two things...you have to use more of it to insure safety or don't use more of it and have more failures.

There has been tons of debate on this subject in other threads...wood is cheaper, but not better. Soviets made use of form shaped plywood that was called delta wood...but there is a lot of hype on these forums about it....it was just plywood that was pressed in a die to make shapes such as fuselage...very ingenious and helped the plywood bear more load and take out some of the variability I was referring to above...but it is still wood. The DM's on aircraft with wood in them is overbaked IMHO and in terms of structural failures, Oleg has modelled wings falling off Ki's, Fw's and Mustangs but has conveniently forgotten the tail sections of La's, 109's, Zekes etc....

Still can't figure out those...planes built for speed have structural failures...yet La's and Zeroes dive and manuever at will free of any of those worries?

3.JG51_BigBear
02-13-2005, 11:31 AM
I think the best bit of evidence that metal is better than wood for aircraft is the number of wooden F-16s you see flying today: 0 http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Demons7th_Wolf
02-13-2005, 11:46 AM
One of the big problems with metal was that it buckled when compressed, just like a piece of paper will bend when its ends are pushed together. In comparison, wood does not buckle as easily. By the 1930s, another aircraft design trend known as stressed-skin structures made this problem more acute. Before this time, aircraft achieved much of their structural strength through their internal frameworks. But in a stressed-skin structure, the covering contributed much of the structure's strength and the internal framework is reduced. This provided a streamlined external surface for the airplane, but made metal buckling failures more likely.

In order to combat the problems of compressive buckling, metal structures had to be complex, with curves and riveting and reinforcement. This dramatically increased the costs of such an aircraft. By 1929, some manufacturers were making metal wings that were as light as wooden ones, but by the end of the 1930s, all-metal airplanes were significantly more expensive than wood and fabric airplanes.

Metal also presumably was more durable than wood, which warped, splintered, and was eaten by termites. But duralumin also had severe corrosion problems. It turned brittle. Unlike iron or steel, which rusted from the outside in, duralumin weakened internally and could fail suddenly in flight. Duralumin corroded even more in salt spray and the U.S. Navy eagerly sought a solution. The Aluminum Company of America (Alcoa) and the Federal government cooperated to develop a material known as Alclad, which consisted of an aluminum alloy bonded to pure aluminum. Alclad solved many of the corrosion problems of duralumin. Soon other alloys were developed that proved effective as well and during the 1930s, all-metal airplanes became much more common.

By the mid-1930s, wood was no longer used on American multi-engine passenger aircraft and U.S. combat aircraft. But in 1938, the British airplane company, de Havilland, began work on a fast, unarmed bomber named the Mosquito. It was one of the most successful British aircraft of World War II, able to fly faster and higher than most other aircraft. More than 7,700 Mosquitoes were built. They were made of spruce, birch plywood, and balsa-wood, proving that even in the era of all-metal planes, older materials could still achieve impressive results.

The lesson of the development of all-metal airplanes is that just because engineers may think that a new material is superior, that does not mean that it will be immediately useful. It may take many years before designers and materials specialists are able to adapt a new material to a new task.

--Dwayne A. Day

Sources and Further Reading:

Brooks, Peter W. The Modern Airliner: Its Origins and Development. London: Putnam, 1961.

Schatzberg, Eric. "Ideology and Technical Choice: The Decline of the Wooden Airplane in the United States, 1920-1945." Technology and Culture, January 1994, 34-69.


For the Zero i recommand reading the book
Eagles of Mitsubishi: The Story of the Zero Fighter by Jiro Horikoshi (The Chief Designer of the A6M zero wrote that book)

DaveP2005
02-13-2005, 02:02 PM
Recall that the Hurricane was mainly wood. The
panels around the engine were metal, and after
the Battle of Britain, they had metal wings. But the fuselages were all wood and even the wings on the early Mk 1's. Wood and fabric was
a lot easier to repair than metal. This was a great advantage for the Hurricane vs the Spitfire. A hole in a Spitfire wing took a while to repair, while a new piece of fabric could be placed over a hole in a Hurricane in a few minutes.

Jasko76
02-13-2005, 02:21 PM
Hurricane was not mainly wood! And definitely not around the engine! Cockpit panels were wooden, and underwing panels on early models were wooden, but that's it. Its structure was made of tubular steel, covered with fabric.

ColoradoBBQ
02-13-2005, 03:34 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Bull_dog_:
There has been tons of debate on this subject in other threads...wood is cheaper, but not better. Soviets made use of form shaped plywood that was called delta wood...but there is a lot of hype on these forums about it....it was just plywood that was pressed in a die to make shapes such as fuselage...very ingenious and helped the plywood bear more load and take out some of the variability I was referring to above.
<HR></BLOCKQUOTE>

It was not just plywood, it was soaked in a epoxy material after being pressed in a die and dried over a couple days to its desired shape.

KIMURA
02-13-2005, 03:49 PM
another aspect of taking rather AL instead of wood is lifetime and easier assembly. An a/c made of wood has a an yverage lifetime of about 2 years, one made of AL 30 years.
The easier assembly aspect - the attachement points of AL/wood (wing to fuselage for example) is more tricky to construct than AL to AL.

Surely the strenght, as already mentioned above. AL has about 3 times the strength than wooden parts.

LeadSpitter_
02-13-2005, 04:07 PM
advantages of aluminum

higher divespeeds, stress high speed, repairing, quick assembley line manufacturing, damage, bullets passed thru most times. parts strenght sturdyness with lighter weight

delta wood advantages

higher wing flex limits, weight slightly, gain in low speed manueverability,

dw wasnt exactly that light but very heavy and was extremely flameable even with the flame ******ant which was just a ploy to give pilots security, it was still extremely flamable from the plastics resins and wood layers also the russians had the best bonding chemicals which fused wood together as if they were solid.

being lighter gives you advantage in accelaration in level flight and manueverability great for low alt dogfighter but bad for high speeds

look at the germans project of the mosquito as well as the british mossie both were extremely sucessful but dive speed stresses were much lower then aluminum airframes, most attacks were from low level hit and run.

p38 vs mossie for example, the mosquito was much faster then the 38 in level flight but the p38 could out dive the mosquito as well as the ju88 which had a higher dive speed then the mossie

dw was very flamable especially when selfsealing tanks were hit with explosive incideary.

another example is the yak9u were the russians were looking for an aircraft that can take more damage, sustain higher dive speeds then the yak3 and la, which the yak9u did.

The weight took away some manueverability down low but was gained highspeed similiar to the p51.

As for the lighter aluminum many times explosive rounds passed thru, with thick wooden frames often struck a solid spar and detonated which is why in all the eastern front guncam available you see yak la mig all burn similiar to zekes from very light hits.

WTE_Wombat
02-14-2005, 04:27 AM
The issue was not which was better but which was available.

When the Mossie was proposed to be built from wood it was accpted because wood had two great strengths:

1. It was available and did detract raw materials from the production of other (metal) planes.

2. It gave them a whole *new* labour force!

The Mossie could be built in factories/workshops unsuitable for producing metal aircraft by tradesmen that knew nothing about producing metal aircraft i.e. the large number of skilled cabinet makers and carpenters who up till then had been useless for producing aircraft were suddenly able to contribute. To the RAF it was like someone was finding them "free" aircraft from thin air.

The Russians made wooden aircraft for the same reasons. They also switched to metal whenever possible.

OldMan____
02-14-2005, 05:11 AM
In fact Aluminum is MUCH more inflamable than wood!!

Wood start burning at low temperatures but generate low burn temperatures. It IS easy to put wood fire out, the simple wind at 300 km/h can make any wood fire go out.

But aluminium, although had a higher aciovatin temperature . . is the MOST COMBURENT ELEMENT!! Nothing burns as alluminium.. It generates MUCH , MUCH higer burn temperatures.. so hot tha could melt steel and could not be put out easily. Also alluminium burn VERY fast.. so in a short time your alluminium wing on fire would disapear... while a wood wing would burn very slowly since air flow is enough to put out or keep low the fire.


Incendiary Ammo uses phosphorous and alluminium dust exactly to be able to put alluminium on fire.


Alluminium planes burn MUCH more than wood ones!!

Aaron_GT
02-14-2005, 06:49 AM
"another aspect of taking rather AL instead of wood is lifetime and easier assembly. An a/c made of wood has a an yverage lifetime of about 2 years, one made of AL 30 years."

That wasn't really a huge issue during WW2. A bomber was unlikely to survive more than about 30 missions and a fighter would be obselete in front line service well before 2 years was up.

In terms of ease of fabrication fabric covered planes were easiest, but with obvious performance deficiencies for fighters and high speed bombers.

"1. It was available and did detract raw materials from the production of other (metal) planes."

Sourcing the wood was problematic, though, as it all had to come from outside the UK (balsa from Ecuador, birch, spruce, and later fir from Canada). The bulk of wood required to build a Mosquito was larger than that of a similarly-sized alumiunium plane and so supplying the raw materials did present a shipping issue across the Atlantic (where a lot of the aluminium was coming from) during the worst of the Atlantic war when space was at a premium. Plus the wood was only really suitable for the Mosquito, whereas aluminium was more generally useful for aircraft production. So the idea that the Mosquito was good because of non strategic materials misses these factors.

An advantage was the ability to use places such as the G-Plan furniture factories for production.

With regard to dive limits, there are issues with the use of wood, but it seems a bit off to compare a single-seat plane originally designed as a bomber interceptor (P38) with a plane designed as a multi-seat level light bomber (Mosquito). Comparing the Mosquito with the A20C would be a fairer comparasion as they were designed for similar roles.

Chuck_Older
02-14-2005, 07:09 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Jasko76:
Hurricane was not mainly wood! And definitely not around the engine! Cockpit panels were wooden, and underwing panels on early models were wooden, but that's it. Its structure was made of tubular steel, covered with fabric. <HR></BLOCKQUOTE>

Jasko is correct- I have seen many pics of burned Hurris- and it looks like a crane is inside the wreckage.

Chuck_Older
02-14-2005, 07:12 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Aaron_GT:

In terms of ease of fabrication fabric covered planes were easiest, but with obvious performance deficiencies for fighters and high speed bombers.

<HR></BLOCKQUOTE>

I'd like to elaborate on that a bit, Aaron-

the fabric covering, say, on an elevator could actually balloon and burst! just wanted to add that bit

p1ngu666
02-14-2005, 07:23 AM
mossies got metal control surfaces later in life when the fabric ballooning and riping became a problem.

oldman is correct, wasnt a ship in the falklands ignited and the actual aluminium burn though?

all planes where highly flamable really...

Akronnick
02-14-2005, 08:16 AM
Well the fact that in most planes a large amount of the internal volume was taken up by fuel and ammunition doesn't help prevent fires

Platypus_1.JaVA
02-14-2005, 09:49 AM
The nosecone of the F-104 Starfighter is also from wood. Why? did Lockheed want to save on valuable construction materials?

Jasko76
02-14-2005, 11:59 AM
It is? Wow, didn't know that!

Since the nosecone (radom) covers the radar antenna, it has to be dielectrical so no interference with the signal is created. For this wood is as good as composite materials. But it does seem a bit backwards to use wood on Mach 2 interecptor!

WTE_Wombat
02-23-2005, 07:32 AM
Quote:..."Sourcing the wood was problematic,"...

I disagree, Wood was plentiful and that was a major factor in choosing wood over aluminium.

There are plenty of reference sources that state this but here is just one:

http://www.nasm.si.edu/research/aero/aircraft/dehavilland_mosquito.htm

that includes this:

..."Wood, and the skilled personnel required to work it, was plentiful while aluminum was in dangerously short supply "...

[even though they can't spell 'aluminium'] http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

triggerhappyfin
02-23-2005, 10:43 AM
Quoted from the site WTE_WOMBAT added alink to.

Wood, and <span class="ev_code_RED">the skilled personnel </span> required to work it, was plentiful while aluminum was in dangerously short supply and aircraft <span class="ev_code_RED">metalworkers were already consumed with producing Spitfires, Hurricanes, and other metal airplanes. </span>



Just about gives us the reason to why some planes were made of wood instead of all metal contruction. To this we should ad the factor that all meatall construction was something of a modernity in aircraft construction/building at least at the start of war. The war time production taking so much effort of peace time economics must have drained the market on skilled metall workers. Metall workers who as such was´nt plentifull of within aircraft manufacturing in first place before war. If you study the production numbers of airplanes you can see the numbers go up as years passes to gain the highest numbers first in the last months of the conflict. By that time the production apparatus were built up and trimmed to top efficiency and by that time allmost all aircraft were all metal constructions. At this time there were a plenty of skilled metal workers.

horseback
02-23-2005, 01:40 PM
In reference to the flammability of aluminum (as we spell it here in the USA, where we conserve vowels, not fuel), I misspent part of my late lamented youth working in an aluminum extrusion plant, where we melted aluminum scrap down and molded it into ingots, columns and the like for pushing through molds not unlike the kind our kids used for clay.

We had to heat it up to 1130 degrees F to melt; in the six months I worked there, I never saw it burst into flames or had a fire problem at the plant, although the furnaces often got up to 1400 degrees F.

About the shipboard fires, my Navy Damage Control training taught me that the main fire danger comes from ship's deck tile or paint burning, followed by fuel or lubricants, which are transferred between bunker areas (for ballasting) or to the engineering spaces via piping.

In the case of a missile strike, often the unexpended rocket fuel can create the extreme heat needed to set metals afire, especially if the engine remains intact & continues to run after the hit.

cheers

horseback