miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
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Post by miletus12 on Jan 17, 2022 9:21:45 GMT
Some people like ships. Some people like ground vehicles. I like classic planes, especially history changing airplanes. Greg's Aircraft and Automobiles Channel covers a lot of these types of aircraft from a historical and technical point of view. The sample I want to present as the leadoff of his treatments is the TBF Avenger.
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miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
Posts: 7,470
Likes: 4,295
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Post by miletus12 on Jan 18, 2022 1:25:05 GMT
Ther FW190 was Kurt Tank's contribution to aviation. Putting aside that he served a genocidal and evil regime and later fled to Argentina to escape Justice, then did work in India and finally returned to Germany after the heat was off: did he actually do anything positive for human progress? The power-egg he invented for the "Butcher Bird"; has common descended down to us in the present as FADEC. (PDF) This Full Authority Digital Engine Control has allowed jet aircraft to be rendered safe enough for commercial aviation to a degree that piston engined (ICE) airliners never could achieve. The antecedent to FADEC was directly the analogue fuel-air mix automatic controls that Tank's plane pioneered. |
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miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
Posts: 7,470
Likes: 4,295
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Post by miletus12 on Jan 19, 2022 2:18:10 GMT
So why did the Americans stuff Allisons into the two birds instead of the Merlin? Details in this case means aspiration choices. The Merlin can use a inbuilt dual speed supercharger and can outperform the single speed super-charger across altitude bands.
The Americans deliberately restricted the Allsion's altitude range to about 3,000 meters. It was a low to mid-altitude band fighter and was going to be effective in the Pacific, China, and the Russian front.
When the Americans or British needed second stage supercharging for high altitude P-40Fs; they built Merlin engined P-40s which could operate to 7,000 meters.
With the P-38, the choice was a second stage TURBO-charger. for high altitude capability. Two reasons. P-51s needed the Packard Merlins. The P-38 could use an American-engined plane saving licensing fees and the Allison P-38 was frankly superior to the Merlin P-38.
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miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
Posts: 7,470
Likes: 4,295
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Post by miletus12 on Jan 22, 2022 15:26:46 GMT
The short version is this: Clarence "Kelly" Johnson found this was the most compact and aerodynamic of the planforms that could comfortably stuff the complex plumbing of the bulky GE turbochargers close to the Allison engines and minimize the aspiration ducting and the oil and engine cooling circuits.
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miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
Posts: 7,470
Likes: 4,295
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Post by miletus12 on Jan 23, 2022 16:40:31 GMT
The choice was basically this one: did one want to rob kilowatts from the front end of the power curve or from the aft end of the power curve?
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miletus12
Squadron vice admiral
To get yourself lost, just follow the signs.
Posts: 7,470
Likes: 4,295
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Post by miletus12 on Jan 26, 2022 2:50:28 GMT
Why did the American navy change the characteristics of their Wildcat fighter? How did the Wildcat change during the first two critical years of American involvement of WWII?
One of the things, that the Bureau of Aeronautics (John Tower) managed to foul up, was the transition from the F4F-3 to the F4F-4 on the Wildcat. The takeaway (not covered in the video) is the added 800 pounds of weight that the -4 added in the form of 2 extra machine guns, armor, self-sealing fuel tanks, and folding wing mechanism. This did two things to the Wildcat. The F4F-4 lost 300 feet climb per minute, lost 2000 meters altitude, and its corner turn expanded from a radius of 400 meters to about 700 meters in radius. That applies to decreasing performance characteristics against the Zero in exactly those parameters where the Zero has superiority.
The added weight was demanded for Martlets, the British version of the F4F-4 which is identical. USNAS aviators opposed adding the armor, guns, and wing-fold mechanism.
Their argument.
a. Armor was useless against the Zero's 20 mm cannons.
b. Self-sealing tanks were okay against incendiary bullets, but useless against explosive cannon shells.
c. The wing-fold mechanism was not needed to operate F4Fs from US aircraft carriers.
John Tower overruled them and mandated Grumman build the "British version" to meet British orders and he enforced uniformity to "simplify production".
My opinion? I think John Tower murdered about 2,000 American pilots bh that stupid decision.
The 6 gun F4F-4 variant had 23 seconds of firing time. The F4F-3 variant had 4 guns and 43 seconds firing time. The USN wanted that firing time for defense purposes.
FM-2s came into service after John Tower was fired for being an idiot. It was more in line with the F4F-3 in flight characteristics. The FM-2 was designed to fight with the added war experience. The altitude bands are biased to low and mid altitude bands where most of the Pacific War air fighting was involved.
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