F4U1D Vrs P51D

[BBGunn]

Hello-F4UDOA and SnakeEyes-  I didn't mean to start an argument here.  I went thru all my other references and could not find any more about dates and tests etc..  Unfortunately book authors tend to leave out dates and model types at times making issues about AC comparsons less clear.  I did find in the North American Aviation alblum that the very first Merlin powered Mustang flew on Oct 16, 1942 in Britain.  I could find nothing else definitive on the F4U vs P51 question.  I suspect that there were quite a few tests conducted that simply did not get into the more mainstream literature.  Anyway-Watch your 6----BBGunn Out

[SnakeEyes]

Nah... not an argument.      Only way to learn is to toss 2 cents into the arena.

In any case, the performance specs with regard to the first post are almost definitively the Allison-powered P-51 (the 'A').  

The first P-51B prototype didn't fly in the US until November 30, 1942 and it had some problems which kept it from flying another hop until late in December.  The 51B was obviously still having teething problems early-on, and based on that knowledge and the characterization that the F4U outfought the 51 "above" 12K, I seriously doubt that the January 1943 match-up was with a P-51B.  

Now, the May 1943 match-up could have *conceivably* been against a 51B, however the specifics of the test match aren't clear (no description of alts the aircraft fought at, for example).

The AHT data is clear when it comes to the aircraft being tested.  But it seems that it implies that the P-51 and F4U are pretty equally matched.

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SnakeEyes
o-o-o-
=4th Fighter Group=

[This message has been edited by SnakeEyes (edited 01-01-2000).]

[funked]

Mock dogfights are worthless IMHO.

[F4UDOA]

Mock dogfights are only worthless if you don't agree with the outcome. Remember this was Army vs. Navy. A rivalry to this day.
Neither side wanted to loose and both were testing their premeir A/C.

If you think it was so worthless why did both sides agree to do it??

The purpose of this post was to show the equality or near equality of these A/C.
I think I proved my point by the reactions
of the P-51 fan club. Now we just need to fix the FM.

F4UDOA

[funked]

"Mock dogfights are only worthless if you don't agree with the outcome. "

No.

I should have been more clear.

They are worthless for building flight models.  I'm sure they had some value in the war, but there are too many variables (pilot) for them to be useful in designing a sim.

[BBGunn]

I think that SnakeEyes post makes sense.  I found a little more info at combatsim.com:
Wing loading F4U-1D= 37 lbs/sq ft :  P51D= 43 lbs/sq ft.  Sustained turn at 6000ft, no flaps: F4U-1D- full circle in 20.5 sec with turn radius of 862 ft.  P51D- full circle in
18 seconds with turn radius of 824 ft.
A6M5- full turn in 16.2 seconds with turn radius of 568 ft.  Fuel loadings were not given but it seems that the P51D has an edge over the F4U-1D in turning ability at lower altitude.  The lower wing loading of the F4U-1D suggests that it should have had good responsiveness on the controls.

[SnakeEyes]

 

The purpose of this post was to show the equality or near equality of these A/C.
I think I proved my point by the reactions
of the P-51 fan club. Now we just need to fix the FM.

Hmmm... anyone know what the heck he's talking about?  Seems like just about everyone here agrees that they're both excellent airframes, and with good pilots at the stick, it's anyone's guess as to which aircraft would come out on top.  

Interestingly enough, the first comment with any real data that anyone makes about the P-51 (other than yourself) was BBGun's comment on the 27th... at which point I remarked that the info he quoted was referring to an Allison-engined 51.  You brought in a reference to a different comparison that says, basically, that the F4U and 51 were largely comparable aircraft.  We agree.  Everyone agrees.  Well, everyone except the pilot wanting a 1000+ mile escort... which the F4U wasn't really capable of.  In short, the only thing that the "51 crowd" did was to point out that your reference, and the reference that BBGunn made, don't refer to the same aircraft.

Oh, if you want to debate with the engineering types around here, I suggest that you go beyond quoting AHT and learn to do the math.

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SnakeEyes
o-o-o-
=4th Fighter Group=

[F4UDOA]

Snake eyes,

I think we are agreeing on the facts that I started this post with. But you don't seem to think I am using enough data? Please read the entire thread before you make that judgement.
My entire beef with the flight model of the F4U-1D revolves around some very fundamental flaws. I base my data around the text from AHT ("America's Hundred Thousand") and the report of the fighter conferance at Patuxant Naval Air station 1944 because these are two well know and respected sources. What people choose do however is interprete the data without reading the book. In an earlier post you mentioned that "obviously the F4U could not have been tested against a Merlin powered
mustang in January of 1943". This is not acurate to the text. On page 24 of AHT it states "Except at altitudes above 25,000ft there was very little to choose between the Corsair and the Army MERLIN-powered P-51in speed, and in head to head performance test showed the Navy Aircraft could outclimb the P-51". I did not interprate that quote. That is directly from the text. No date is given for the test and no mention of 12k is given as a referance. But there are other figures too examane. The F4U-1D takeoff run is not modeled accurately. It should leave the runway well ahead of it's Army counterpart with a takeoff run of approx. 840Ft with a gross weight of 12,289lbs. More than a full load out of fuel and ammo. Where as the P-51D leaves the ground at 1185FT. at 10,176lbs. This is no flaps at sea level with full internal fuel and ammo. And not reflected at all in the AH Flight model.
Also on page 597 if you look at the graph comparisons you will notice the F4U-1d time to climb to 20K at Military power seems to be
8min where the P-51d seems much closer to 10minutes at the same power rating. (Hitech you asked for the data, and this where I find it.) As proof of these quoted sources with page numbers I would ask you to look at wing loading where as the Corsair has lower wing loading and power loading at sea level.
Page 513 useful load #1
F4U-1D Weight=11,962 and wing area=314
Wing loading=38.09
Useful load 1 fighter page 603
Power Loading at 12,289lbs 2000Hp
At sea level=6.14
P-51D Weight=9,611 page 329 wing area 233.19
Wing loading equals 41.21
Weight=10,176lbs Hp=1490
power loading at sea level=6.83
This does no corrulate to the current AH flight model as far as climb ability and turning capiblity of these two A/C.
I am not in anyway saying that the F4U should be an uber plane or turn or Climb with a Spitfire However I do think that and A/C with more robust performance should be modeled to accurately reflect the actual wartime flight data acheived during testing. This is not data from any manufacturer, it is completely durived from flight testing of these two very
fine a/c by the services that used them.
Remeber manufactures ALWAYS embelish the performance of there product. Just look at the Bradley Fighting Vehicle.

F4UDOA

"I would rather loose a battle and be sure to win the cause than win the battle and be sure to loose the cause"
Unkown

[BBGunn]

Hello F4UDOA- if you are interested in more data on the F4U you might try www.nara.gov/  to search for more data.  National Archive record group 72 is for the Bureau of Aeronautics.  Report no 02153 is one that the author W. Musciano quotes.  These files may not be digitized but you might give a search a try.  I guess I share some of your frustraton-sims tend to give AC certain differing (almost stereotyped) qualities and I have the feeling from other sims that I've played that the Corsair gets automatically thrown into the looping E (boom & zoom) fighter category.  This may partially be because of the recommended prodecures for engaging Japanese 0 fighters but it was not soley a boom and zoom fighter in real life.  Greg Boyington and many of the other marine pilots did their share of turning.

[SnakeEyes]

I'm not arguing whether the F4U is correctly modeled in AH.  Pyro himself would probably admit to wanting to do much tweaking to all of the existing flight models.

What I'm saying is that the data that BBGunn provided says that the P51 tested in January 1943 had performance that was equal to, or better than, that of the F4U *under* 12K; and was outperformed by the F4U *over* 12K.  That anecdotal description is clearly referring to the Allison-engined P-51 (a Mustang I, Ia, II, or P-51A).  The Allison-engined P-51 was a superb low altitude performer.  At altitudes above 15K its performance tailed off sharply, however, as it did not possess a supercharger.

In contrast, exactly as you state, the tests reported by AHT show the F4U and P-51 be roughly comparable, with the P-51 only attaining a significant speed advantage over 20 or 25K.

In short, the AHT data and BBGunn's data are most likely NOT the same tests.

That's ALL I'm arguing.  Period.  Nothing more, nothing less.

Now, as for arguing about how the F4U should perform, based upon how the P-51 performs... well... that's less than reliable IMO.

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SnakeEyes
o-o-o-
=4th Fighter Group=

[F4UDOA]

BBGUN, you are a man of great wisdom. Thankyou for looking beyond the obvious. You are right about people assumig that the F4U could not or was not a manuverable A/C. It is simply because of the tactics used against the Japanese A/C which could turn on a dime that the boom and zoom tactics were developed. The fact is that tactics like the Luftberry circle that could be employed over Europe against less manevable A/C would be suicide in the pacific. There is a general feeling of supriority on the European plane set people that does not allow them to realize while German A/C were in fact more rugged and were of higher performance those A/C would have had no more luck turning with Jap fighters than any other. The fact is that the F4U, F6F and F4F were three of the most agile fighters produced in the US. Especially at low speed as a requirement for carrier landings.
SnakeEyes, Thankyou for being reasonable.
I think we agree on the major point I was making at the start of this post. That these two A/C are very compatable in performance, especially below 25K. My only complaint is the great disparity in performance in the FM
in Aces High. A few minor tweeks and I will be a very happy simm pilot. I am not looking for an uber plane. Just a harder look at the data thats out there.

Thanx
F4UDOA