U.S. built wooden aircraft

[gjs238]

With war looming, or already underway in various areas of the world, would it have been advantageous for the US to build wooden aircraft immediately prior to and/or during the early stages of WWII?
The Hawker Hurricane and later de Havilland Mosquito come to mind, but there may be others.
Or perhaps new designs. After all, North American Aviation came up with the P-51 after being asked to license-produce P-40's.

 

[nuuumannn]

They did; the "Bamboo Bomber", Cessna Bobcat. Hurricanes weren't built of wood like the Mosquito. Very early Mk.Is had wooden wings, but the fuselage structure was steel tube covered in fabric with a wooden 'dog box' just aft of the cockpit, ahead of the cockpit was ali panels. You could describe them as 'mixed media'.

 

[Shortround6]

With war looming, or already underway in various areas of the world, would it have been advantageous for the US to build wooden aircraft immediately prior to and/or during the early stages of WWII?
The Hawker Hurricane and later de Havilland Mosquito come to mind, but there may be others.
Or perhaps new designs. After all, North American Aviation came up with the P-51 after being asked to license-produce P-40's.

Very little advantage. The US didn't have a real shortage of aluminium for any extended periods of time, spot shortages aside. Wooden construction can be almost as weight efficient as wood construction but it has to be a rather innovative form of wood construction like the Lockheed Vega fuselage or the Mosquito and not the conventional form of wood construction used in most 1920-30s aircraft. The Japanese tried to make a wooden Ki 84. it weighed 600lbs more than the Aluminium one. Bf 109s with wooden tails required a steel plate bolted under the oil cooler for balance.

The Hawker Hurricane WAS NOT constructed of wood. Wood was used in it's construction but they are not the same thing. The Fuselage was a steel tube girder with wood formers to fair out the fuselage to the desired shape. See this photo:

Hawker Hurricane - fuselage | Flickr - Photo Sharing!

or

All structural loads were handled by the steel structure. It might be quite possible to fly a Hurricane (suitable ballasted) with the fabric and formers stripped from the fuselage. Might bring new meaning to "open cockpit"

Several US companies were fooling around with molded wooden Fuselages in the very early 40s. They were getting good results but required large amounts of synthetic resin and ovens large enough to "bake" the entire fuselage in. One of these processes was tried for the Bell XP-77 which wound up overweight from projected figures and late in delivery.
The US used up most of it's wooden aircraft construction capability on building the Grasshopper fleet and in building gliders.

Waco CG-4 - Wikipedia, the free encyclopedia

 

[FLYBOYJ]

Bell XP-77 - Wikipedia, the free encyclopedia

"On 16 May 1942, the USAAF recommended the construction and testing of 25 XP-77s. The aircraft featured a single-engine, low-wing monoplane with mainly wood construction, equipped with tricycle landing gear, a Bell trademark that bestowed good ground handling."

 

[mhuxt]

Didn't the US build paratroop and transport gliders out of wood?

I suppose tht's not what the original post is getting at, but all the same...

The plywood skins used in the Mosquito were manufactured in Wisconsin, IIRC.

 

[gjs238]

According to Wikipedia, the Hughes H-4 Hercules:
- was "Built from wood because of wartime restrictions on the use of aluminum..."
- "Due to wartime priorities, the design was further constrained in that the aircraft could not be made of metal."
- "To conserve metal, it would be built mostly of wood..."
- "Development dragged on, which frustrated Kaiser, who blamed delays partly on restrictions placed for the acquisition of strategic materials such as aluminum..."

So subject to the accuracy of the above, it seems that at some point there was some concern over the availability of aluminum and some sort of restrictions enacted.

 

[gjs238]

Bell XP-77 - Wikipedia, the free encyclopedia

"On 16 May 1942, the USAAF recommended the construction and testing of 25 XP-77s. The aircraft featured a single-engine, low-wing monoplane with mainly wood construction, equipped with tricycle landing gear, a Bell trademark that bestowed good ground handling."

Pasted from the Wikipedia page above:
"The Bell XP-77 development was initiated by the United States Army Air Forces during World War II to produce a simplified 'lightweight' fighter aircraft using so-called "non-strategic" materials."

It seems that at some point there were concerns about "strategic" materials such as aluminum.

 

[N4521U]

What a great kit plane that XP-77 would be....
Metal tho, or comp I guess.

 

[vikingBerserker]

It does look kind of fun to fly though.

 

[Shortround6]

According to Wikipedia, the Hughes H-4 Hercules:
- was "Built from wood because of wartime restrictions on the use of aluminum..."
- "Due to wartime priorities, the design was further constrained in that the aircraft could not be made of metal."
- "To conserve metal, it would be built mostly of wood..."
- "Development dragged on, which frustrated Kaiser, who blamed delays partly on restrictions placed for the acquisition of strategic materials such as aluminum..."

So subject to the accuracy of the above, it seems that at some point there was some concern over the availability of aluminum and some sort of restrictions enacted.

There was concern, just as there was concern about a lot of materials (like steel) as production increased by leaps and bounds. However the production of Aluminium also increase by large amounts compared to pre-war levels and aside from some spot shortages the anticipated or feared large scale shortage never happened.

" In three years, Alcoa built over 20 plants: 8 smelters, 11 fabricating plants, 4 refineries, and operated them for the government. Total investments in the industry during World War II rose to $672 million, of which $474 million were Alcoa investments. Employment rose from 26,179 in 1939 to 95,044 by 1944."

Aluminium production in 1942 --472.4 thousand tons
Aluminium production in 1943 --834.8 thousand tons

"Between 1939 and 1944 production rose from 146,000 short tons to over 800,000 short tons with purchased metal amounting to over 600,000 short tons."

Sentences in quotes are from Alcoa web pages.

The large increase in aluminum production was not fully anticipated or foreseen. restrictions may have been enacted, but I don't recall reading about any program being canceled just to conserve aluminium. In fact the US army was considering going from pierced steel plank runway material to pierced aluminium plank runway material at one point during the war.

 

[johnbr]

Don't for get the Hughes H-2 it was wood with plastic in a pulp.

 

[Jabberwocky]

Bell XP-77 - Wikipedia, the free encyclopedia

"On 16 May 1942, the USAAF recommended the construction and testing of 25 XP-77s. The aircraft featured a single-engine, low-wing monoplane with mainly wood construction, equipped with tricycle landing gear, a Bell trademark that bestowed good ground handling."

Bell's proposal for an improved XP-77 estimated that switching to an all-metal construction would have reduced the weight of the aircraft by 122 lb. That's about 4.4% of the empty weight, 3.2% of the loaded weight or 15.1% of the basic structural weight.

 

[A4K]

Didn't the US build paratroop and transport gliders out of wood?

I always thought the WACO CG-4A Glider was, but seems that's not the case - usual ali tube and canvas construction.

 

[Capt. Vick]

What a great kit plane that XP-77 would be....
Metal tho, or comp I guess.

I have always thought this as well. Tweak it a little and you have a "rare warbird"!

 

[evangilder]

Bell XP-77 - Wikipedia, the free encyclopedia

"On 16 May 1942, the USAAF recommended the construction and testing of 25 XP-77s. The aircraft featured a single-engine, low-wing monoplane with mainly wood construction, equipped with tricycle landing gear, a Bell trademark that bestowed good ground handling."

It looks pretty tiny. Look at the pilot in the photo. It looks like the poor guys got in there with a shoe horn! Looks like a fun little airplane though.

 

[gjs238]

Bell's proposal for an improved XP-77 estimated that switching to an all-metal construction would have reduced the weight of the aircraft by 122 lb. That's about 4.4% of the empty weight, 3.2% of the loaded weight or 15.1% of the basic structural weight.

Wonder how an all-metal Hurricane would have performed.
But then again, I guess why would one bother when you have the Spitfire.
Still, for academic reasons, I wonder how an all-metal Hurri would have performed.

 

[davebender]

I agree.

Britain and Soviet Union didn't produce much aluminum so they were forced to use other materials for airframe construction. USA and Germany did not have that problem.

 

[johnbr]

Do not forget the Hughes D-2.

 

[Shortround6]

Wonder how an all-metal Hurricane would have performed.
But then again, I guess why would one bother when you have the Spitfire.
Still, for academic reasons, I wonder how an all-metal Hurri would have performed.

About the same. The wood in a Hurricane bore no structural loads. It was used to fair out the steel tube framework of the fuselage to the desired exterior contours. There was no wood in the wing and in the fuselage it was from the cockpit back. ou would have saved some weight but in a 6000lb airplane it would be minimal. Since a Hurricane I had to carry ballast when fitted with a constant speed propeller lighting the rear fuselage just would have meant more ballast.