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metal was the trouble free option
There is nothing wrong with the P-38 that could be fixed by wood or Merlins. First, it was designed to use a wing section which wasn't suitable for a fighter. Second, its configuration compromised completely to allow for all the gear that goes with turbocharging was a restriction on its adaptability. Primarily because there was no room in the central pod after the pilot, armament and nosewheel were accommodated. This is not to say it wasn't a decent fighter for a twin but it was short on potential in any other area. A conventional twin might have worked better. Something like the F7F maybe, or a developed XP-50. Or maybe the right single-engine plane was always going to be better, or a twin more suited to multi-role.
I don't disagree at all but it is a question of expertise and knowledge. You wont get me climbing aboard a wooden 747 but de Havilland knew generally knew what they were doing, and designed within the limits of what they knew. You cant just use "metal" just as you cant just use "wood".I don't think they thought metal was trouble free, just that it was lesser of two evils.
The push for metal "structure" had occurred in the late 20s and early 30s. A number of British Biplanes came in two versions, one with wood structure and one with metal structure.
They were both fabric covered. The British air ministry at times would not accept a design that used wood "structure" in some design competitions.
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the other question, why wasnt the Mosquito license built in the USA and used instead of the P-61
A USAAC squadron was equipped with Mossies for recce missions. Apparently many were crashed on takeoff due to torque swing and the air corps decided Mossies were to dangerous and that was that.
What is your source for that?
As far as I am aware, two squadrons operated PR Mosquitoes for photo reconnaissance and weather reconnaissance from when they received them until the end of the war.
One squadron was equipped with NF.XXXs late in the war.
btw the Air Corps (USAAC) ceased to exist in 1941, when it became the US Army Air Forces (USAAF).
What is your source for that?
As far as I am aware, two squadrons operated PR Mosquitoes for photo reconnaissance and weather reconnaissance from when they received them until the end of the war.
One squadron was equipped with NF.XXXs late in the war.
btw the Air Corps (USAAC) ceased to exist in 1941, when it became the US Army Air Forces (USAAF).
I don't disagree at all but it is a question of expertise and knowledge. You wont get me climbing aboard a wooden 747 but de Havilland knew generally knew what they were doing, and designed within the limits of what they knew. You cant just use "metal" just as you cant just use "wood".
They may not have enjoyed the F-8, the Mosquito B.XX converted to PR configuration, but went back to the Air Ministry and received 100 PR.XVIs and a few trainers. They also later received the NF.XXXs.
I believe the F-8 was one of very few foreign designed and built aircraft to receive an official USAAF designation.
Neither the Spitfire or the Beaufighter received a USAAF designation, though they were operated by USAAF units during the war.
They never really tried a bigger center pod, one plane adopted for experimental work of a different nature excepted.
Please note that the F7F lost about 50-80 gallons of fuel when fitted out to carry a radar operator so it wasn't exactly operating with an abundance of extra space either.
Two seat seat F7F carried 25 gallons less than P-38J or L, but it did carry more guns and ammo,
Trying to power a conventional twin with a wing area of 455sq ft and the size of the F7f that went with it using a pair of 1100hp Allisons wasn't going to get you a very effective fighter either.
A USAAC squadron was equipped with Mossies for recce missions. Apparently many were crashed on takeoff due to torque swing and the air corps decided Mossies were to dangerous and that was that.
A USAAC squadron was equipped with Mossies for recce missions. Apparently many were crashed on takeoff due to torque swing and the air corps decided Mossies were to dangerous and that was that.
That's a thousand more than any of it's metal contemporaries. The A20 and B26 didn't even make to the end of the war.Barely 1000 Mosquitos built post war, and as soon as the jets turned up, even those were very quickly gone from front line service.
Wood was an historical anomaly, not a wonderful design innovation. The Mosquito would have been a better plane if all metal. While DH continued to use wood, it didn't produce durable aircraft.
I agree, I worked in metals and testing of metals all my life and was fascinated by the use of wood, because you don't make it you can only cut down lots of it and select what you want based on experience and testing. In general de Havilland rejected 90% of woods presented to get what they wanted.True but metal was easier to work with from an engineering standpoint. If you had good quality metal (not defective) of a certain alloy you knew what it's yield and breaking strengths were, what the compression strength was and what the bending strength was. It was available in tables from either makers or a standards laboratory, wood was harder to get good figures on as wood is much more variable. Once you start using using composite structures (spruce veneers over balsa cores using glue brand XX,) or multiple layers of wood veneers impregnated with plastic resins and baked in ovens the engineers were in rather strange territories. Information was prepriority in some cases and duplicating lab tests might be iffy?
Because airplanes are complicated structures with complicated loads (aircraft often had multiple loads acting on on piece of the structure in different directions at the same time) even metal was not quite the look up the number needed in the book/chart and make the part to the size specified.
You can get structural strength charts for wood but sometimes they come with little notes attached like temperature and moisture content of the wood in addition to the density of the wood (how many pounds per cubic in of wood at what moisture content gives you strength XXX??
for those who are interested.
https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/ch04.pdf
Specifying and testing a certain grade of aluminum alloy is a lot easier.