What if the P-38 was made of plywood a la Mosquito?

[Razgriz1]

Would it have improved the performance or the maneuverability of it?

 

[parsifal]

I don't think the turn performance of the P-38 was restricted by its airframe strength. neither its performance (dive climb speed).
One would have to compare weights really I think

 

[Elmas]

It depends from the Safety factor accepted by Top Brasses ( … and Pilots, of course). With the same safety factor of a metallic P-38 I'm not so sure that a wooden P-38 would have been much ligther, improving performances and manouverability.

Probably the ship could have had a slightly better aerodynamic due to the smoothness of the surfaces.

But I don't know how a wooden airframe could not rot in the Guadalcanal jungle…

 

[GregP]

Pretty quickly!

The jungle in Viet Nam rotted the electronics, our underwear, books, food, and was generally hard on anything made of natural materials as well as some synthetics. I don't think the British got long life and ruggedness from their wood airplanes in tropical jungle climates. I think they got short but relatively useful lives from them.

 

[parsifal]

Pretty quickly!

The jungle in Viet Nam rotted the electronics, our underwear, books, food, and was generally hard on anything made of natural materials as well as some synthetics. I don't think the British got long life and ruggedness from their wood airplanes in tropical jungle climates. I think they got short but relatively useful lives from them.

Hi Greg

Mosquito was pretty resistant to moisture actually. RAAF Mosquitoes were in service of one sort or another until 1962, in very limited numbers. For most of the 50's they were engaged in aerial survey work, the first complete survey in Australia at the time. this survey extended to the tropics and further included the PNG and I believe Borneo as well.

No signs of rot there. The problem with the earlier versions of the Mosquito, from which this myth extends from, was in the adhesive used to keep the bonded material together. After several mossies were lost after they disintegrated in mid-air, the problem was traced to this issue. The Mossies used in the tropics used a different type of bonding adhesive, which overcame this problem. I worked alongside a couple of cranky old salts who worked with the Mossies, and they commented on how resistant to moisture on several occasions.

I served in the tropics for some extended tours. your right about organics not enjoying tropical heat and moisture, but metals fare far worse im afraid, including so called inert materials used in airframe construction. The only materials able to withstand this punishment without constant maintenance, are materials like Brass. Add a little salt to the mix and watch what happens. the biggest threat incidentally is to electrical circuitry.

 

[pbehn]

Since wood and metal have different properties I suspect a wooden P 38 would look like a d-H Hornet.

 

[GregP]

I've seen what jungles do to wood first hand, so I'll be skeptical. But not so skeptical that I'll deny facts.

Let's say, I would prohibit wood for a plane in the tropics and let it go at that. Also, I won't build a wood plane in a dry area and them move it to a wet one or vice versa. Seen that one, too, and it isn't a happy thing.

But build wood in a one area, keep it there, do good maintenance, and it's very durable. I'd fly most CAP-10/20s.

Have nothing against wood. Just want it to last in a military airplane. NONE are wood today. But many good GA planes are, and I have no issue with that.

Lee Behel was killed when his wood GP-5 came apart at Reno. That has never been explained as far as I know. It was well built! The workmanship was extraordinary, from first hand observation. The wing failed at 400 mph some 100 feet high. Hard to recover from. Wood may or may not have been the culprit, but I'll take Aluminum or other metal any day unless it is a slow plane (< 200 mph). Then wood is fine.

I'm sure someone will throw in a Mosquito or Hornet. Always loved them but would decline to fly it in the tropics. Your opinion may vary. And that's OK. Ditto a Vampire.

If I had a BOAT, wood is great. But it also needs proper care and feeding or you sink! .... maybe slowly ...

 

[parsifal]

LMAO about the slowly sinking wood boat. That happened to me you know.....

 

[yulzari]

DH Hornets were used in Malaya with no issues and I can personally attest to the hot damp climate. But they were using the later synthetic families of glues.

The weather in NW Europe combined with poor workmanship and poor glues caused Fokker DVIII/EV wings to fail in 1918. In one documented case they opened up a hole to check and water poured out.

Equally one can point to the changes in carrier planes v land ones to protect them from salt water corrosion.

My conclusion is that well executed wood works, poorly executed metal does not. Equally the opposite applies.

The Mosquito is a good guide in that it operated successfully in climates like Canadian winters, desert heat and dryness, maritime cold and wet and tropical heat and damp. But you could not copy DH construction for the P38 because there simply would not be enough balsa wood to go round.

 

[wuzak]

Would it have improved the performance or the maneuverability of it?

I believe the P-38 was already more manoeuvable than the Mosquito, and had superior performance as a fighter.

 

[Elmas]

But there is not only damp and moisture in very hot and humid climate: generally there are thousands species of worms, insects and fungi more than willing to make of wooden wings and fuselages their food....
In very dry climates like some parts of Australia or cold climates such Canada wood can resist much better than in a jungle.
The problem is not much in the glue used, it is in the wood itself.
Certainly, if you think to use an aeroplane just for months, if not even weeks or days, like in WWII, how much an aeroplane will last is not an issue.

 

[buffnut453]

DH Hornets were used in Malaya with no issues and I can personally attest to the hot damp climate. But they were using the later synthetic families of glues.

So were de Havilland Venoms with their wooden fuselages which are pretty close to the P-38s from a high-level design perspective. Not sure how twin booms with built-in turbo-superchargers would work with wood, though. I suspect there would be structural issues given the load placed on that part of the airframe and the construction techniques required to make such components from wood...and that's before we consider any heat shielding/dissipation issues.

 

[wuzak]

So were de Havilland Venoms with their wooden fuselages which are pretty close to the P-38s from a high-level design perspective. Not sure how twin booms with built-in turbo-superchargers would work with wood, though. I suspect there would be structural issues given the load placed on that part of the airframe and the construction techniques required to make such components from wood...and that's before we consider any heat shielding/dissipation issues.

Mosquitoes had metal panels around the engine bays.

I believe the Hornet was mixed construction - with a lot of aluminium in the structure.

 

[buffnut453]

Correct, and the Venom only had a wooden cockpit nacelle. My point was more about how to build a P-38 out of wood. IMHO the tail booms would be a major challenge.

 

[Shortround6]

Since nobody ever built a metal Mosquito we don't know what the weight difference is. We do know there are different forms of wooden construction. We do know that a wooden Japanese KI84 was about 600lbs heavier than the Aluminium one, we also know that a version using more steel was also heavier. We know that Russian planes also got lighter (in structural weight, they used the weight savings to add things) as they got more metal parts. We know the wooden "tail" on the 109 was heavier and required a counter balance. We Know the Americans had trouble with several wooden aircraft projects coming out over weight.
We also know the P-38 was designed for a 12 G ultimate load factor with a an 8 G service load factor (later versions may have slipped a little?) while the Mosquito was 8 G ultimate and a bit over 6 Gs service load. Not a criticism of the Mosquito, it wasn't designed as a single seat day fighter and it was designed to British rules, not American. I would not that many post war US jets had service G factors lower than 8 Gs.
The Americans also had some sophisticated wooden construction techniques, perhaps they weren't as good as the Mosquito but without real engineering data and a structural engineer or two we don't know if they are equivalent. Some US methods used a lot of resins and baking entire fuselages in large ovens. It may not have been true but they were advertised as rot proof

They were reported to be subject to decomposition over time but 10 out of 262 built were still on the national register in 2001, 58 years after last built.

I could be wrong but part of the Mosquito's strength/weight could be due to it's size. As in a 4ft diameter tube is stronger (at least in bending) than a 3ft diameter tube if both use the same wall thickness. How much thicker the 3ft tube walls have to be to make it as strong I don't know. If they have to be 33% thicker than the wight comes out even.
The Mosquito was a much larger airplane and trying to build the P-38, especially those skinny tail booms, out of the same materials as the Mosquito might have been difficult.
The Hornet did use slightly thinner fuselage skinning than the Mosquito. While the inner and out layers of plywood stayed the same the inner layer of balsa wood was changed from 7/16 in to 5/16 in in thickness. Please note that balsa wood can weigh, in general (model airplane contest grades excepted) between 8-14lbs per cubic ft and picking 12lbs for ease of math means that q 1 in thickness 1 sq ft in size weighs 1lb. the 1/8 in difference between the Hornet and the Mosquito is worth 1/8 of a pound or 2 ounces per square ft. Using lighter balsa the difference is less.

good website on the construction of the Hornet; fuselage construction

Parent : The de Havilland "Hornet" & "Sea Hornet"

The Hornet was also much smaller than a Mosquito,
with 9 ft less wingspan, 80% of the wing area, around 5-6 ft less fuselage length ( depends a lot on radar domes, which can add another few feet to either) and the Early Hornet weighs about 3,000lbs less empty than a Late model Mosquito (both with two stage engines), refer to the above website for the use of a partial metal wing spar.

 

[tyrodtom]

I've seen how long wooden boats, and canoes can last IF they're maintained.

But you can get to any area in them fairly easy to insure there's no breaks in the paint, varnish, or what ever protection you're using on the wood to prevent moisture from getting inside the wood.

The older fabric covering they used on aircraft only lasted a few years anyway under normal use unless they spent their lives in hangers.
So the fabric was stripped, the wood inspected, revarnished, and recovered.

But they are so many areas in a aircraft covered, and impossible to inspect, especially if the outer covering is wood.

Surely the Mosquitoe's wooden inner structure had some kind of varnish, paint, or some form of protection to stop, or slow moisture intrusion into the wood..

 

[Shortround6]

Surely the Mosquitoe's wooden inner structure had some kind of varnish, paint, or some form of protection to stop, or slow moisture intrusion into the wood..

The probably did but most of these coatings are permeable to some extent. Yes rain water will run off but weeks or months in either a dry or extremely wet environment will change the water content of the "protected" wood.

Wood boats that spend most of their time in the water do fairly well. Ones that speed a few months on shore and then go back in the water require good bilge pumps the first few days after launch until they swell up again
Ones that spend their life on a trailer and only get "dunked" a few days a month can also stay pretty tight.

 

[pbehn]

Since nobody ever built a metal Mosquito.

The Mosquito was a much larger airplane and trying to build the P-38, especially those skinny tail booms, out of the same materials as the Mosquito might have been difficult.

Great post SR.

In the interests of discussion, it is true no one built a metal mosquito but the Hornet and Tigercat were basically metal and wooden competitors for best twin engined piston fighters. Metal and wood are completely different, I think building a P-38 out of wood would be as successful as building a wooden fire guard. Whether a single seater, twin Allison engined fighter could have been made is another question but the P-38 was a USA plane and the USA was not short on metal and had the time space to train people to make metal planes.

 

[swampyankee]

I suspect that were Lockheed to have designed a wooden aircraft to meet the same mission as the P-38, it would look completely different. The other question is whether the USAAF would buy any wooden fighters.

 

[Shortround6]

Of course it was several years later than the P-38.
It also suffered from being overweight, delayed development and was designed around an engine that never made it to flight status (or even test bench?)
The intended "buy" changed quantity several times and finally resulted in just the two prototypes.