XP-39 II - The Groundhog Day Thread

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So are we just making up our own formulas now? With simpler methods?

Why the hell does Boeing and Lockheed pay so much for these engineers? I'm going to recommend to my boss that we replace all the engineers with guys from web forums. Not only will we save a lot of money, we'll improve the F-22's performance. At least on paper...
 

Greg, please see post #700 Messerschmitts do not want to burn and fall and #726 Summary.

The phenomena called overclaiming can really skew the actual results dramatically.
 

Must have been a fairly formidable ground assault airplane, if the Soviets thought so. Since they did have the famous IL-2 Sturmovik, from fairly early in the Great Patriotic War.
 
Must have been a fairly formidable ground assault airplane, if the Soviets thought so. Since they did have the famous IL-2 Sturmovik, from fairly early in the Great Patriotic War.
Their main role was battlefield air superiority. Escorting bombers and intercepting German bombers.
 
There you guys go again; speaking in tongues and handling serpents at worship!

HEY! Careful now, you're treading into dangerous territory, Troll George and I own the copyrights to snark in this here forum. I'm the one that's easily confused when you big brain types start spouting all your book learnin' nonsense. (check how many times I've had to take drgondog to task...)

It's hard to countenance this faux pas on your part but I can be magnanimous in this instance, George on the other hand, well, he's the one you have to watch out for.
 
Would like to see your calculations, thanks.
 
Would like to see your calculations, thanks.

I tossed my numbers when this discussion seemed over.

Look at Greg's calculator, he's got it down pretty good and you're able to play with some of things we discussed.

The error on the page I mentioned, I'll post later
 

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HEY! Careful now, you're treading into dangerous territory, Troll George and I own the copyrights to snark in this here forum.
And I contest those copyrights as invalid! Call your attorney; see you in court. Or would you prefer pistols at twenty paces or sabers toe to toe? In that case, call your second; see you on the meeting ground.
It's hard to countenance this faux pas on your part but I can be magnanimous in this instance, George on the other hand, well, he's the one you have to watch out for.
Well, St George awarded me a "Funny" for this post, so I see no threat there...unless there's an implied "Farm" after it, in which case, "Them's fightin' wuhds, Suh!"
 
My challenge, your call, Sir: pistols or sabers? I have a matched pair of John Wilkes Booth style .41 cal Derringers. Will that suffice? Our seconds will attend to the loading, if that suits.
Being a Southern Gentleman, I choose pistols suh...

Yours:



Mine:


Unless you prefer long guns, but I warn you suh, I'm a master tactician when it comes to those...

 

It is interesting to compare models' weights as tested. Most test reports tell you that they have ammo on board, etc. On some reports you need to click on the "See entire report HERE" to get the weights.
The 'as tested' weights grew from 6592 in the YP-39 to 7871 in the P-39Q. That's a significant change at just under 20%, while bhp went up from 1090 to 1420, ~30%.


Model...........weight as tested in pounds.........bhp................max speed.................time to 15,000'

YP-39..............................6592.......................1090..................368 mph....................4.6 min

P-39C.............................6689........................1150..................379 mph...................~4.3 min

P-39D.............................7525........................1150.................Not given....................Not given

P-39D.............................~7800......................1170.................368 mph....................5.7 min

P-39D.............................7450........................1172.................370 mph....................Not given

P-39M.............................7430........................1420.................385.5 mph.................4.38 min

P-39N.............................7274........................1420.................398.5 mph.................4.15 min

P-39N.............................7301........................1390................. Not given..................3.82 min

P-39Q.............................7871........................1405.................385 mph....................4.5 min

P-400 British tests..........7845........................Not given...........355 mph...................~5.3 min


Source: P-39 Performance Tests
 
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It is the elephant in the room.

Btw, what is your source for this?
The P-39, in Soviet service achieve the highest number of victories of any U.S. type, in any conflict.
 
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