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NACA L-353 reports Spitfire CL max at cruise condition (2650 rpm, 3 3/4 lbs boost), gear up, flap up, ports open, as 1.68.
What does this do to the calculations?
Hop - I'd like to know where that came from....
Listen folks - when I hear pilots (even the greatest aces and test pilots) make statements that the aircraft is "worn out," I have to laugh. Many of these folks had little or no maintenance backgrounds and made these determinations sometimes by outward appearances and comparing one same aircraft to another.
What wears an aircraft out?
As many of us seen, in the back of each Pilot's notes or flight manual are performance numbers. If the aircraft meets those numbers that's the bench mark of performance.
Don't get me wrong, I have the utmost respect for those who flew these aircraft during these tests but I think those who recorded pilot statements as a result of these test did not press for real explanations or were not technical enough to understand what the test pilot was talking about
Interesting thing is Hop, that whenever we discuss a Spitfire testing, if the results are bad, heck, even if the paint job from artistic POV is being discussed and criticized you dismiss those results by whatever means possible, but in the same time tests of crash-landed, shot down, 190's and 109's maintained and flown by untrained personel, you take as apsolute truth and perfect example of a service plane. Now that's just funny
Try WWII Aircraft PerformanceSo ... where are all these performance graphs located?
We'll assume a CLmax of around 1.45 for the Ta-152 as CLmax is going to increase slightly with AR. The Spitfire's CLmax is going to be 1.35 - Any objections ?
Clmax figures with the engine running isn't valid, what we need and what we're using is free float figures. With the engine running CLmax is going to be raised quite significantly
more so by the a/c which provides the most thrust which would be the Ta-152.
Speed is going to be 600 km/h, the absolute higest speed for both a/c at SL.
As to 'e' (Oswald efficiency factor), well I'm guessing the Spitfire's to be abit higher despite the aerodynamic twist of the wing.
Fly for your life, as already quoted.
Fair enough. However, I am not an experienced mechanic, yet give me a worn out car of the same model as the one I currently drive, and I will be able to tell if it's worn out. Sloppy steering, sluggish acceleration, worn shocks, poor brakes, all should be apparent to a driver with experience of that model.
Tuck had a lot of hours in Spitfires, and so should have known if the Spit was worn out or not.
Yes, but that says nothing about handling. A well maintained engine has no effect on roll rate, which is determined by the correct rigging of the ailerons. For that you have to know the droop, the tension in the cables etc. Was the Spitfire being serviced by squadron mechanics who had experience of such things? Did it even have standard ailerons for them to have experience on?
Everything described has to do with maintenance - if the item is well maintained there should be no difference.
Even in WW2 there was a methodology in aircraft maintenance that should of kept the aircraft maintained to established parameters.
If he was here I would ask him. I've seen high time pilots complain about a perfectly good aircraft. Everything was in limits, all rigging and systems were checked and for some reason they thought there was something wrong with it and appearances always has a lot to do with it. Not being there one could only speculate - That's why you have probably seen that web page about airline pilot writing up components and the mechanics coming back with some smart @ssed remark. (#4 engine seems to be running rough - replaced running shoes)Certainly. But if it was well maintained, why would Tuck describe it as "very tired, very sloppy"?
Um, Kurfurst, you've reposted the chart that shows exactly what I said. Apart from the Spitfire at 30 lbs stick force that you've drawn in, that is.
NACA 868 shows roll rates at 50 lbs stick force for all aircraft apart from the Zero, where the force limits are unknown. The 50 lbs line for the 109 falls below all the other aircraft I can see.
Actually it's well above the Spitfire V test done by the NACA, and also the Spitfire V roll tests done by RAE, which states 71 lbs is required for a steady rate of 45 deg/sec roll at 400mph. The 3 year old 109F can manage that with 66 lbs.. As for the Zero, there's not even a roll rate curve for 400 mph.
Of course here we're comparing an. apprx. IAS conversion for the roll rate tested on a 3 year old Bf 109F without the reinforced Bf 109G wings, against tests done on new planes, probably, and no later improvements present on the Bf 109 like aileron Flettner tabs either.
No, as we have been over ad nauseum, they are tested results for the Spitfire V, given along with the Mustang and Typhoon figures by the RAE as a comparison with the Fw 190.
Brilliant, we know now that the NACA graph above is based on a RAE test of a MkV, which MkV's roll rate results are far above any other Spitfire's roll rate.
Four problems with the Naca roll figures for the Spitfire.
Like :
1, It's made by an impartial organisation
2, In a professional manner
3, It isn't high enough
4, It isn't high enough again
First, it was a very worn aircraft.
Robert Standford Tuck:
Dear Hop, you put forward a Bf 109F-2 roll rate test as gospel, and aircraft that was produced somewhere in 1940 or 1941, and was tested after 3 years of use, in the end of the 1944. And you say it's represenetative for the type.
Yet, when it comes to a Spitfire, you argue that a plane that was freshly produced in April 1941, and was immidiately delivered afterwards to the US and tested in December 1941 is not representative because the aircraft was 'worn out' for which you give us a quote from a pilot which doesn't tell if it's the same plane at all, if the comment refer to the state before or after the test, and I'd really like to see the quote in it's full context, not just a snippet. The report would have surely noted if the results would have been effected by this alleged wear, but it does not.
In any case, it's a cheapo excuse for the tested results which you don't like.
Second, it was a Spitfire Va. That's the last of the machine gun armed variants, and so didn't have the wing strengthening applied to the cannon armed aircraft.
Neither did the 109F had the 109G's wing strenghtening applied, yet somehow such considerations only apply to the Spitifre...
Dear Hop, can you answer us why do you dismiss an American test on a brand new Spitfire on the basis that it was 'worn out', and that it didn't have the wing strenghtening of later types, whereas you hold as gospel a test done a 3 year old Bf 109F that neither had the wing strenghtening of later types?
What do you think was 'worn out' more, a 109F in the end of 1944 or a Mk V in the end of 1941 ?
Va's also came from the factory with fabric ailerons, so we don't even know if the "metal ailerons" fitted were the standard production items.
..We don't...? I am sorry but this is a cheapo trick, as it's written there and you've already admited it was discussed before, so you must know it.
Again :
Desription of the the Supermarine Spitfire airplane
Name and Type : Supermarine Spitfire VA (Air Mininstry No. W3119).
Engine : R-R Merlin XLV
Weight, empty : 4960 lbs
Normal gross weight : 6237 lbs
Weight as flown for tests : 6184 lbs
Ailerons (metal-covered)
Lenght (each) : 6 feet, 10 1/2 inches
Area (total area, each) : 9.45 sq. feet
Balance area (each) : 2.45 square feet
Third, Naca published the report containing the 868 graph post war. They chose to use the RAE's figures for the Spitfire, rather than their own.
Of course but what does it prove? Nothing apart from NACA used a RAE graph in one of it's reports. NACA didn't test roll rate up to 400 mph, though I doubt RAE would, but in any case, they took their data because it covered a larger speed range.
Besides it's interesting that RAE later commented the NACA test results and considered NACA's findings regarding the rate of roll at high speeds optimistic and in no way objected the results obtained with regards of roll, neither there's a comment either that the aircraft would be worn out at all. RAE on the NACA report :
RAE seems to have actually tested the effect of clipping of wings on the Spitfire, and the findings are quite different than what the Spit cliiped/unclipped roll rates displayed on the NACA chart suggest, ie. that there would be a linear huge rate of roll increase at all speeds. Quite the contrary, ie.
Or let's see the aspect that the clipped winged Spit V on the NACA 868, if the results are true, should roll quite easily with the FW 190A. Compare it with the pilot interviews done with Spitfire pilots when clipped wings were introduced :
Or compare another RAE trial with a Spit V with the Spit V on the NACA 868 :
Ie. the NACA 868's Spit V roll rate seems to be around 40 degrees/sec with 50 lbs stick force. However, the other RAE Spit V roll rate data shows that for 45 degrees rate of roll, 50% higher stickforce is required.
To put the long story short, the NACA 868 Spitfire roll rate curves are in conflict with every other roll rate test made for the Spitfire, either by the British, Americans.
That means either the tested aircraft was an exceptionally good example of it's type, or perhaps a testbed with some experimental aileron fitting.
Fourth, the RAE tested the roll rates of the Spitfire against other aircraft. We'll leave out the fact they said it rolled much better than the 109s, because you will just come out with excuses that they couldn't fly the 109 properly.
The RAE, Hop? Are you sure you're not making this up?
Hop, pilots who flew actual examples of the 109G and Spitfire have to say this:
Roll performance is similar to a Hurricane or elliptical wing tipped Spitfire. A full stick roll through 360 degrees at 460kph takes 4 to 4.5 seconds without using rudder, and needs a force of around 20 lbf. One interesting characteristic is that rolls at lower speeds entered at less than 1g, such as a roll-off-the-top or half Cuban, have a markedly lower roll rate to the right than to the left. Therefore, I always roll left in such manoeuvres.
Ie. Dave Southwoods words, the full one can be read at the 109lair.
Hop we all understand that in your eyes, the Spitfire did everything better than any other aircraft, it had greater mileage than the Mustang, dived to greater speed than the P-47, rolled with the FW 190, not to mention your latest theory I've read that the RAF was doing a lot more combat against the Luftwaffe than the USAAF in the late 1943, and above it did everything better than those pesky Bf 109 that still shot it down in rows for some odd reason!
But please, try to stick to reality.
But they also tested against a range of American aircraft, which they used extensively, and with manufacturers support.
This is quite irrelevant to the subject I think.
Hop,
You've screwed up your calculations big time.
And besides it is CLmax you want to be looking at, not CL in straight flight.
And as to thrust, well sorry but you can leave HP out of this, its actual thrust we're talking about here
and the Ta-152H's new prop provided over 300 kg more thrust than the FW-190A's and with 50 less PS.
And as to the Oswald efficiency factor, what in the wolrd makes you think that the Spit's has a figure which is higher by more than 0.03 ???!
Oh and about why you only use free float figures, simple, CL changes are variable with thrust and how big a part of the wing it covers - using free float figures allows us to figure out the effectiveness of the body itself.
This time I'll also do speed figures in m/s like you, but again not that it makes any difference.
Surprise surprise !! Its the same result !
So finally here's some good advice for you Hop; Stop cherry picking and stop acting like you know something you do not !
Brilliant, we know now that the NACA graph above is based on a RAE test of a MkV, which MkV's roll rate results are far above any other Spitfire's roll rate.
A 1g 360 degree full stick roll in a clipped wing Spit IX at 250 KIAS and 5000 ft takes 3 seconds
Like :
1, It's made by an impartial organisation
2, In a professional manner
3, It isn't high enough
4, It isn't high enough again
Dear Hop, you put forward a Bf 109F-2 roll rate test as gospel, and aircraft that was produced somewhere in 1940 or 1941, and was tested after 3 years of use, in the end of the 1944. And you say it's represenetative for the type.
Yet, when it comes to a Spitfire, you argue that a plane that was freshly produced in April 1941, and was immidiately delivered afterwards to the US and tested in December 1941 is not representative because the aircraft was 'worn out' for which you give us a quote from a pilot which doesn't tell if it's the same plane at all, if the comment refer to the state before or after the test,
Dear Hop, can you answer us why do you dismiss an American test on a brand new Spitfire
What do you think was 'worn out' more, a 109F in the end of 1944 or a Mk V in the end of 1941 ?
.We don't...? I am sorry but this is a cheapo trick, as it's written there and you've already admited it was discussed before, so you must know it.
Again :
Desription of the the Supermarine Spitfire airplane
Name and Type : Supermarine Spitfire VA (Air Mininstry No. W3119).
Engine : R-R Merlin XLV
Weight, empty : 4960 lbs
Normal gross weight : 6237 lbs
Weight as flown for tests : 6184 lbs
Ailerons (metal-covered)
Of course but what does it prove? Nothing apart from NACA used a RAE graph in one of it's reports. NACA didn't test roll rate up to 400 mph, though I doubt RAE would,
RAE seems to have actually tested the effect of clipping of wings on the Spitfire, and the findings are quite different than what the Spit cliiped/unclipped roll rates displayed on the NACA chart suggest, ie. that there would be a linear huge rate of roll increase at all speeds. Quite the contrary, ie.
Or compare another RAE trial with a Spit V with the Spit V on the NACA 868
That means either the tested aircraft was an exceptionally good example of it's type, or perhaps a testbed with some experimental aileron fitting.
The RAE, Hop?
Roll performance is similar to a Hurricane or elliptical wing tipped Spitfire. A full stick roll through 360 degrees at 460kph takes 4 to 4.5 seconds without using rudder,
Hop we all understand that in your eyes, the Spitfire did everything better than any other aircraft, it had greater mileage than the Mustang, dived to greater speed than the P-47, rolled with the FW 190,
not to mention your latest theory I've read that the RAF was doing a lot more combat against the Luftwaffe than the USAAF in the late 1943,
This is quite irrelevant to the subject I think.
The Spitfire XIV rolls much more quickly.
.Here again the Spitfire has a marked advantage at all speeds.
Well, they went on to clip large numbers, so they must have found some benefit. They also note that there is a large benefit on those Spitfires with heavier than average ailerons, which suggests NACA 868 actually shows the results for a poor example.
Actually Soren I've got my calculations correct, because I am using the correct units.
You got yours wrong because you mixed the units.
Firstly, it's not CL in straight flight, unless you believe a plane flies straight whilst generating twice as much lift as it weighs.
The problem with your new calculations is that the planes are turning at very different rates. The Ta 152 is generating 6.6 times its own weight in lift, the Spitfire 7.4 times its own weight. The Spitfire is therefore turning much tighter in your comparison.
What in the world makes you think it's not? The truth is you are just guessing, and forgive me for pointing out that it's just guesswork.
It does of course because it allows you to work out how tightly they are turning. That's the sort of reason they use consistent figures in equations.
Source for this claim?
You got yours wrong because you mixed the units.
Huh ?!! I dare you to point it out !
Yeah thats right, there has been no mixing of units at all !
Listen Hop, a CL of 0.5 is not something you get whilst turning goofball, and that silly remark of yours just supports the fact that you know nothing of what you're talking about.
Oh and btw generating a 2:1 lift to weight ratio is very normal in straight flight - so yes I do believe that.
There is no problem with the math I presented, the problem lies with you Hop and your total lack of knowledge on aerodynamics. The Spitfire isn't turning much tighter at all, its got an 11% percent advantage in lift pr. weight which gives it a slightly higher initial turn rate,
Wrong again Hop !
I'm not just making wild guesses here, I'm basing my assumption on the 'e' figures in a graph comparing high AR wings of the same shape as the Ta-152's with a fully elliptical wing with no twist.
Its there right infront of you man ! The exact same difference in percentages as when I used km/h instead of m/s !
And as to pressure - at SL at 15 Celcius it is 1.164 exactly.
Oh and btw, using different pressures in the equation doesn't change anything between the Ta-152 and Spit.
So, I can summerize your POV, you dismiss every single Spitfire roll test done by the NACA, RAE, the RAAF, the RAF, except the single test that's details and conditions are unknown but are the most favourable to the Spitfire and in disagreement with the findings of other tests by the same organisation, RAE?