Allied Gold-Match

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the graph on Mark William's site gives no ref. to the orginal source and WE KNOW HE HAS A VERY HIGH PRO-SPITFIRE BIAS! Also, the graph represents performance from the Griffon 61, 65, 66, 85, 86, and 90 - only the 61 and 65 are relavent for WWII, so the Griffon power ratings are probably overstated. These are the only BHP graphs I can find, so they will have to do.
You try to discredit this guy on one hand, then use his material on the other? Did you think to ask him for a reference before trashing his integrity or motives? Why didn't you find your own chart instead of using one from someone you distrust? Maybe you'll do anything on a forum to advance your pro American agenda? Did you intentionally overlook the Griffon 61 chart? http://www.spitfireperformance.com/spit21ads.jpg
This shows 2,050 at 8,000 ft. MS gear and 1,780 in FS gear, presumably without RAM. Still, I'm sure the Englander lies, just like the arrogant American.
 
Soren said:
The chord is longer, and the wing a little thicker, and that will make a difference.

The increase in thickness will hardly make any difference as the Spit's airfoil gets its max thickness earlier along the chord, and although this adds more drag it also adds more lift.

The difference is minimal near the root, and practically non-existant near the tip. The Corsair airfoil is that of the tip from about the bend out, so there is little difference at all.

Soren said:
But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.

No but the difference is there, and the curvature is superior with the Spit's wings.

Not really. I've got the data, I'll post a pic soon (have to figure out how to render it still).

Soren said:
I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !

I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts. The Corsair also has a lot more active elevator and rudder surface area.

=S=

Lunatic
 
I don't think it's necessary to be abusive....we all have our respective patriotic feelings, but this is an incisive discussion that's drawing facts details from the past, as well as what has been revised and updated today. I for one think it's been bloody well presented so far, and as stated, I love both these aircraft....Back-up dude, and watch n' learn.....

Gemhorse
 
I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts.

At 0-350mph the Spit XIV very easely out-turns the F4U-4 ! At 350-450mph the difference is less pronounced, but the Spit still out-turns the Corsair.

The Corsair also has a lot more active elevator and rudder surface area.

RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same.
 
Soren said:
I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts.

At 0-350mph the Spit XIV very easely out-turns the F4U-4 ! At 350-450mph the difference is less pronounced, but the Spit still out-turns the Corsair.

The Corsair also has a lot more active elevator and rudder surface area.

RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same.

The rudder and elevator control surfaces are bigger on the Corsair is bigger. Look at them carefully.
 
RG look very carefully at these two pic's ! The Rudder on the Spit XIV is bigger ! (The pic of the Spit is actually taken at a bit longer distance.)

F4U1.jpg

SPIT7.jpg
 
Soren,

Those pictures are not at the same scale. The Spit XIV is 32 ft 8 in in length. The F4U-4 is 33 ft 8 inches in length. Yet in your photos the Corsair appears to be shorter than the Spitfire. The length of the moving part of the rudder is about the same for the two planes, but the Corsair's is taller by a fair amount.

=S=

Lunatic
 
RG,

It is very clear that the Spit XIV's rudder area is bigger !
 
Right scientific study here I just measured my swede from my nose to the back of my bonce 20cm so using this as a guide I measured the F4u pilots head at .5cm thus making the Corsair rudder approximately
5 bonces wide X 7 bonces high.
The spitfire pilots head (allowing for the skid lid) is 4mm this makes the Spites rudder 5 bonces wide X 11.1 bonces high.
Therefore ip so facto the surface area of the Corsair is about 35 Square bonces where as the Spitfires is about 55.5 Square bonces even allowing for the fact that the Spites rudder is not rectangular it would still mean the Spitfire having a rudder several bonces larger than the Corsairs.
and before anyone says it my nose is only average in size. :p
 
I could get a more accurate measurement but i would need a mean average bonce size so Lanc if you and a few other guys can measure your heads from the tip of your nose to the back of your craniums we should be able to solve the problem of the tail size differential by using our heads.
 
It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.

And the Corsair tail is taller too, even in the photos as given not accounting for the mis-scaling.
 
RG_Lunatic said:
It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.

And the Corsair tail is taller too, even in the photos as given not accounting for the mis-scaling.

How can the scale be off when both pics are presumably taken with the same camera, and when the two pilots are about the same size ? The picture isnt off scale or distorted at all, wich can clearly be seen by looking the wheels wich are perfectly circular.

Btw the Corsair's rudder isnt taller on the pic or in the real world at all, infact the Spit's rudder is a good deal taller ;)
 
The lower portion of the Corsair's rudder (right above the fuselage) doesn't confer the same control surface benefit that the Spitfire's does at this location. This is because the air that flows over this portion on the Corsair's rudder is disturbed to a greater extent by the top of the fuselage behind the cockpit. That area is significantly above the lower portion of the Corsair's rudder.

The Spitfire's fuselage is a straight shot to the rudder. Only the cockpit disturbs the airflow.

Use each pitot's head as a rough measure of units for height and see how many head's high each is.

Hint ... The Spitfire wins this one on height of the rudder.
 
Soren said:
RG_Lunatic said:
It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.

And the Corsair tail is taller too, even in the photos as given not accounting for the mis-scaling.

How can the scale be off when both pics are presumably taken with the same camera, and when the two pilots are about the same size ? The picture isnt off scale or distorted at all, wich can clearly be seen by looking the wheels wich are perfectly circular.

Btw the Corsair's rudder isnt taller on the pic or in the real world at all, infact the Spit's rudder is a good deal taller ;)
\

The Spitfire should be almost a foot shorter than the Corsair, but in those pictures its longer. Therefore it must be off in scale - OR THAT IS NOT A SPIT XIV!

Below I've superimposed a F4U scaled to about the right size (maybe a little small):

f4u-4_vs_spit14_rudder_comparison_01_129.jpg


To be honest, I cannot tell which one has more rudder fin area. So I was mistaken in saying the Corsair had more.

But.... you said "RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same." But, as you can see...

spitxiv_vs_f4u_scale_851.jpg


They are in fact not even close! The Corsair has far more rear stabalizer and elevator area than the Spitfire.

=S=

Lunatic
 
Davidicus,

The F4U flies nose down, and the F4U-4 added a few degrees more attack to make it fly even more nose down, so the airflow is not as disturbed as that of the Spitfire which flies level. Not that this makes much difference.

=S=

Lunatic
 
I think it does make a difference as to the lowermost portion accounting for perhaps 13% (my estimate) of the total rudder area which has the dorsal portion of the fuselage in front of it. (Both aircraft's rudders have air flow disruption from the canopy to deal with although the Spitfire's appears more aerodynamic.)

As to the angle of attack in which the plane is oriented in level flight, I was not aware of this. Are you sure?

The P-47's transition from razorback to bubble canopy is illustrative here. The tail lost structural stability from the loss of the dorsal spine. The loss of the dorsal spine, however, also casused greater stress on the rudder as a result of increased unimpeded airflow to the rudder.

p47-3.jpg
 

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