I don't understand how some planes ended up being so fast

[Carboncrank]

I would be rather leery of using operational mistakes/mishaps in evaluating performance of aircraft.
A missed rendezvous can happen to any aircraft unless it can be shown that due to excessive head winds or some other factor that a particular aircraft could not over come that another one could.

I would also note that while the P-51 was a much superior escort fighter the P-47 was constantly evolving. Jan 1944 seeing the start of the equipping of the P-47 planes already in theater with under wing tanks in addition to the under fuselage tanks to extend range.
The under fuselage tank itself under going a series of changes and the 150 gal, under fuselage tank was introduced in Feb 1944 just in time for "Big week". it added 15 minutes of flying time (over the 108 gallon tank?) and extended radius to 350 miles.
Big week escorts were mostly P-47s.
May of 1944 starts to see the P-47D-25 show up with another 65 gallons of internal fuel which really extends the radius, even though most are being sent to the 9th Air Force. And most in theater P-47s are being transferred to the 9th Air Force as quickly as deliveries of P-51s allow.

There was a fair amount of overlap and things were happening very quickly. As of Dec 1st 1943 the Mustangs still had lots of bugs and were not yet operating with either rear fuselage tanks or under wing drop tanks. By March of 1944 all three US fighters were using under wing tanks and often larger than what what they were using in the fall of 1943 for the P-38.
Please remember that it could take several months from when a particular serial number aircraft rolled out the door of it's factory in the US and when it flew it's first combat mission in Europe.
A lot of decisions were made without the benefit of combat experience as there just wasn't time.
Fortunately they guessed correctly.

On dec 1st 1943 there were zero Mustang squadron supporting bombers and they had external tanks available from day 1. They are on all Packard/Melin Mustangs. There were no bugs to be worked out. With very little pilot familiarization they went straight into combat. Where do you get this stuff? A source every once in awhile would be nice.

You're saying nobody thought to put a drop tank on a jug before Feb 44? It's true the jugs far outnumber the mustangs in big week, but a quick look at the numbers of planes and numbers of kills shows astoundingly higher kill per sortie number on the mustangs. I'll zero in on that more if I can but you can see it clearly here. Even without the long range considerations the Mustang was a superior air to air weapon. The best of the war.

Big Week - Wikipedia

The first Mustang missions are flown Feb 11, 44 66th Fighter wing, 357th fighter group.

357th Fighter Group - Wikipedia

They didn't augment Jug squadrons, they replaced them. I find no evidence that he D model jugs had any impact on the air to air campaign.

I'm still hearing denial that range was the biggest problem of the jug.

More corrections later. and I have more to say about that 20 minute gap. I know how difficult rendezvous are but planning is suppose to take that into account. Why do you think their had to be a last minute hand off in the first place? Because the second group flew a slightly different route using different fuel settings just to cover the last 20 minutes. This is the exact reason they stopped trying to fly into Germany for 5 months. This mission was the deepest I find in the dailies until Feb, and it was not very far into Germany. This mission was right on the edge of what was possible for the big fuel sucking Thunderbolt and the foul up was taken very seriously, heads rolled, because it was known exactly what would happen if they didn't hand off properly. 5 planes in 20 minutes and that was just from my uncles squadron alone. This was a mission not just military but intended to send a message to Hitler's economic and political backers as well. You'd have to research I. G. Farben Industrie to find it. It was the worlds largest chemical company. Actually, the largest company of any kind in the world at the time. Wall Street made a lot of money off them and been helping them set up field offices in Canada before the war. Why Canada? Because big money Nazi apologists were getting enough heat already without being tied to them. The largest American investors were pro nazi even after the blitz. The company and it's family were the main financial supporters of the Nazi party all through Hitlers rise to power. It wasn't just a military target, it was a political one and an economic one aimed to hit the Nazi party in the pocketbook and it was supposed to send a clear message that similar considerations would be on the table in targeting. I started out just being curious about the target my uncle was trying to bomb and it led a complicated shameful story. I found the details in 1946 congressional hearing on American financial ties to the Nazi party. It was an idea that had come from the top and the brass all the way down to the group level knew it was of particular interest to the white house. What happened was an embarrassment.

 

[Carboncrank]

Horsepower at altitude matters. P-47 that went close to 500 mph have had 2800 HP at 30000 ft. Weight plays almost no role in speed.

it did not

 

[Carboncrank]

"Carboncrank, posted:The Mustang's smaller air frame, narrow nose and laminar flow and low drag far outweighed having less HP.

Laminar Flow was never accomplished on the Pony.

You can argue with NASA Langley about that one.

https://crgis.ndc.nasa.gov/historic/XP-51_Mustang#Development_of_the_Laminar_Flow_Airfoil

 

[tomo pauk]

a lot easier to dis me than to make a counter argument isn't it?

There is no correct answer to a question with incorrect facts. There is no right answer to " how in the world does a P-47 have any business having a top speed of 500+ MPH" because P-47's did not fly 500+, yet posters were trying to answer it anyway.

I did something I don't see hardly anyone on her do. I gave sources. Not just any clickbait sources, the best ones I know.

Facts don't care if they are popular. In fact, the notion that popular is more important than being right is the root of the current problem in the White House. Social media is target rich for con artists and manipulators.

I also did something I don't see much of. I admitted and error. I went on to point out the correct number didn't change my point, but I admitted the error. I didn't dance around it or ignore it or continue to claim it's true like our current President would do.

So, in your case it wasn't enough to hit dislike, you had to tell me and justify it by saying some mumbo jumbo about faulty this and that, that you can't be bothered to explain, but you are sure to point out you don't think I'm friendly enough.

I don't care.

Whether my position on the topic is the "correct" one has nothing to do with the manner in which it's delivered. I care more about clear-eyed skeptical analysis and what the truth is far more than I do whether I'm popular.

I'll humbly suggest taking another look at mad_max's post here, #30, that I completely agree with.
Local and/or today's politics are barely if ever discussed here, at least in this sub-forum. My take is that it is better that way.
Numbers/figures are sometimes hard to agree about, however the less-than-frinedly attitude can be spotted promptly. I did it a few times, looking back it didn't painted a nice picture about myself at the end. Still trying to improve on that.

The emphasis on making everything a popularity contest is the facebook way of life. And THAT has the world up to it's neck in fact facts, fake news, and lies propagated by people that know how to manipulate algorithms. That is how the Russians got Donald Trump elected. Fake news, falsehood and propaganda shoved further and further up the rankings because someone hits the "like" button in a worlds where people care more about what their friend believe than they do the truth. The internet was invented for searching factual data. I use it all the time so I don't say stupid stuff. Social media is a perversion of that intent. People raised in a world where the internet has always been their have become astoundingly lazy about using it for what it was intended for. So I see more and more stupid stuff.

I don't know how the original poster got the 500mph plus notion, but I know where they didn't get it. They didn't get it through actual data on the craft. More likely they think they remember someone posting it online in some other discussion. Fact checking? Who needs it right?

I think you should point out where you think I'm wrong and save you judgments about my personality to yourself or make them in private.

If this forum turns out to be a clique it won't stop me from posting about something I'm passionate about and know a lot about and can back my notions with facts, for the most part. None of us is free of point of view bias of some level. I work very had to challenge bais in my own thinking. If I was going for a bias point of view I'd ague the Hellcat as the best combat aircraft. My father flew them off aircraft carriers.

Nobody will try to prevent you posting whatever you think it is relevant, nor any of us here is bias-free. People that regualrly post here are from all generations, from 20 to 80 year old folks, many of them don't care much about facebook and similar novelties.
OP was perhaps thinking about this P-47 that supposedly made 505 mph: link

BTW - there is no clique here. I've verbaly clashed with some members before on this forum on some topics, and yet agreed with them on some other topics. Just like in real life.

it did not

Did not what?

 

[Carboncrank]

Whatever the merits or demerits of this thread it does not deserve to be closed/locked because one contributor brought in modern day politics which has no relevance to the discussion.

My comments stemmed from someone going out of their way to make a personal comment about me.

I do get the point though and will try and refrain from politics even though I was talking about a mindset more than a person regardless how I feel about people's behaivoir on the internet to be linked to the situation we find ourselves in now.

And then there is the interconnectedness of things. Even when just trying to talk about a bombing target I end up finding out there were politics involved.

 

[YF12A]

All I can add is what I was told from someone who flew 70 + missions from 1942 to 1945, from the first mission over Germany, led the 1st Air Division on the Schweinfurt massacre until the end of the war as a Group Co. He believed the P-51 made the long range missions possible. This coming from someone who had his own highly modified razorback P-47D to fly what became Ramrod missions when he wasn't flying a B-17.

 

[Ivan1GFP]

Did not the F4U Corsair and F6F use the same engine? (answer is yes)
And the Corsair still had a higher top speed and I'm assume because it had a bigger propeller (13ft 4in)?
The Corsair was designed with the gull wings, to accommodate the big propeller (and to shorten the landing gear).
The F6F Hellcats propeller was 13ft 1in, Could 3 inches make much of a difference?

According to Corky Meyer, Grumman Test Pilot, the two were nearly identical for maximum speed and differences were mostly due to the way that the ASIs were driven.
I don't believe this was entirely accurate but the differences were probably not as high as one typically finds in the books.
The Corsair did have a speed advantage but it wasn't much and was probably due to the slightly smaller wing area and smaller frontal area and coefficient of drag.
Depending on your source, speeds for the two aeroplanes could be:
F4U-1 Corsair: 390 MPH - 417 MPH
F6F-5 Hellcat: 370 MPH - 409 MPH

Your note about the propeller differences is interesting because:
The Hellcat started with a 13 foot 1 inch propeller while the Corsair had a 13 foot 4 inch propeller.
During the Corsair's production run, it was found that the 13 foot 4 inch propeller was not optimal and the aircraft would actually go slightly faster if RPM was reduced from maximum (probably because of transonic effects on propeller tips).
It was then retrofitted with the 13 foot 1 inch propeller from the Hellcat.
I first found this in a British test report and found the retrofit propellers mentioned again in a comparative test conducted by the US Navy of a captured FW 190A-5/U4 against a Corsair and a Hellcat. (See attached document in last section above signatures.)

- Ivan.

 

[Carboncrank]

Carboncrank, google can provide much useful information but will also tell me what the Holy Chalice looks like. The original post just asked a question, there are many possible answers.

There are no possible CORRECT answers to a question with a false premise.

 

[Carboncrank]

It quite obviously wasn't. It was no match for anything at altitude from 1939 to 1943. It was no match for a Griffon engined Spitfire or an Me 262 when they came in to service. What it did have was good performance at all altitudes, fantastic range and huge numbers. Those numbers were magnified by the use of P 47s P 38s and Spitfires. After D Day when combats were at lower altitude it was no match for a Tempest in performance nor a P 47 for firepower and durability.

Mistakes made in the early days of the bombing offensive were not the fault of the machines involved. It was a learning experience for the group and required many more re con planes and weather reports to solve.

Horsepower at altitude matters. P-47 that went close to 500 mph have had 2800 HP at 30000 ft. Weight plays almost no role in speed.

Of course it does. The Mustang has less horsepower yet goes faster. Weight. It takes lift to lift. Along with lift comes drag. The more weight the more lift required to lift it into that thing called flying. The the more lift required the more drag. The more drag the harder it is to go fast. Not going to find a source for that because it's homework you should do yourself. Basic Newtonian physics.

And NO the jug did NOT go close to 500 mph. No P-47 made in meaningful numbers could do close to 500. I don't think even the final X version would do that.

That the false part of the question that started this whole thread. Stop repeating it.

 

[Carboncrank]

I'll humbly suggest taking another look at mad_max's post here, #30, that I completely agree with.
Local and/or today's politics are barely if ever discussed here, at least in this sub-forum. My take is that it is better that way.
Numbers/figures are sometimes hard to agree about, however the less-than-frinedly attitude can be spotted promptly. I did it a few times, looking back it didn't painted a nice picture about myself at the end. Still trying to improve on that.



Nobody will try to prevent you posting whatever you think it is relevant, nor any of us here is bias-free. People that regualrly post here are from all generations, from 20 to 80 year old folks, many of them don't care much about facebook and similar novelties.
OP was perhaps thinking about this P-47 that supposedly made 505 mph: link

BTW - there is no clique here. I've verbaly clashed with some members before on this forum on some topics, and yet agreed with them on some other topics. Just like in real life.



Did not what?

it did not go near 500 mph.

 

[Carboncrank]

The importance of top speed and rate of climb in addition to the obvious, is that they are indicators of an aircraft's potential.
The faster plane will have more options.

top speed is done flying straight and level. As soon as you begin to bank the speed falls off. Deflection of the control surfaces cause drag, flying with wings tilted/banked causes drag as in the loss of lift has to be countered by an increase in the angle of attack of the wing.
Take two planes, one that can do 330mph and one that can do 360mph at the same height. The 2nd plane can actually be performing gentile maneuvers at 330mph, wide turn or gentile climb as opposed to just flying straight and level.

Even if you are at 300mph the faster plane still has more options because it has more surplus power to accelerate with, or climb or compensate for a steeper bank angle/tighter turn.

Nobody had enough power to compensate for a 5-6 G turn for very long even if the pilot didn't black out, without loosing altitude.

The "faster" plane may not be using it's "speed" at all times but you can bet the pilot (if he is any good) is using the extra power that speed margin represents.

How much speed is lost in climbing or in turns or any kind of maneuver depends on the plane. Nobody had enough power to compensate for a 5-6 g turn very long without running out of airspeed. That's one of the problems with the claim the jug would turn well. the jug loses speed in turns much faster than a smaller plane. Bigger wing area, more lift required to make the turn, more loss of momentum. That's what makes the Jugs top speed at 32k feet so irrelevant. if you have to put the jug into a tight turn you'd better not run out of ideas before you run out of airspeed. The size and weight come with a price tag. You'll find yourself quickly at a lower altitude in a plane that's not so fast anymore. The Jug loses speed at lower altitudes faster than smaller air frames do.

It was best off strafing trains.

 

[tomo pauk]

Of course it does. The Mustang has less horsepower yet goes faster. Weight. It takes lift to lift. Along with lift comes drag. The more weight the more lift required to lift it into that thing called flying. The the more lift required the more drag. The more drag the harder it is to go fast. Not going to find a source for that because it's homework you should do yourself. Basic Newtonian physics.

And NO the jug did NOT go close to 500 mph. No P-47 made in meaningful numbers could do close to 500. I don't think even the final X version would do that.

That the false part of the question that started this whole thread. Stop repeating it.

it did not go near 500 mph.

So you say. Other people say it did. I take orders from moderators here and from my wife at home.
P-47 vs. P-51 speed comparison includes drag vs. thrust. We know that eg. P-51B/D was faster than Spitfire IX with equivalent engine, despite the Spit being lighter. Drag is cruel, per Bill Marshall, and P-51 was both with lower coefficient of drag (any of the 3 kinds) and it was a smaller A/C that the P-47.
At pg. 125 of the 'America's Hundred thousand', it will take a 1000 lb weight increase on the P-51D in clean state to lose 3 mph. I'll reiterate that weight plays almost no role in max speed for ww2 aircraft as we know them.

 

[pbehn]

There are no possible CORRECT answers to a question with a false premise.

Well then you should have learned the danger of basing a conclusion on a false premise.

You claim for the P 51 was this "The mustang was obviously the best fighter of the war in all regards." In this you must be very precise about names. The Mustang was not an escort fighter, it was an Allison engined tactical recon plane, it had very good but limited performance because it could not perform at high altitude. The P 51 B/C and D were what made the legend and some of these were operated by the RAF and called Mustangs. When it comes to best fighter the only thing that is obvious is that it is an opinion not a fact. As a British citizen I place huge store on being there. The P-51, P 47, P 38, P39 were fine aeroplanes but they were not there in 1939/40 so you may as well discuss F-22s. Similarly, it is all very well to complain about the short range of the P 47 as your anecdotal post does, but where was the P 51? It wasn't there! When the P 51 B/C was introduced in numbers the USAAF had already learned a lot and it was this knowledge as well as the P 51 which led to success. Without the Spitfire and Hurricane the P 51 has no place to take off and land from in Europe, that is my opinion, it is a valid opinion so the P51 is not "OBVIOUSLY" anything, as great as it was.

Please Carboncrank have some respect. There are experts in aerodynamics post here and their posts will show in chapter and verse why laminar flow was not achieved on the P 51. There are veterans of the European bomber campaign still post here. There are people who have written histories and can quote chapter and verse on the subject you claim to be an expert. There is no conspiracy against your view, just put them in a more friendly way.

 

[pbehn]

It takes lift to lift. Along with lift comes drag. The more weight the more lift required to lift it into that thing called flying. The the more lift required the more drag. The more drag the harder it is to go fast. .

But at very high speed most drag is not involved in providing lift is it? If you cannot say how much of the P 47 and P 51 drag was caused by providing lift, there are people here can help you.

 

[Shortround6]

On dec 1st 1943 there were zero Mustang squadron supporting bombers and they had external tanks available from day 1. They are on all Packard/Melin Mustangs. There were no bugs to be worked out. With very little pilot familiarization they went straight into combat. Where do you get this stuff? A source every once in awhile would be nice.

You want a source, fine. America's Hundred Thousand, page 333, right hand column, 6th entry.

"Dec 1'43 The P-51Bs of the 354th Ftr.Grp. are being 'de-bugged". They also are not yet operating with the extra fuselage fuel tank or with external tanks."

and right below it,

"Dec 1'43-Twenty-four P-51Bs of the 354th Ftr.Grp. tanke their first fighter sweep over Belgium and France led by Lt.Col. Don Blakeslee of the 4th Ftr.Grp. There is no enemy action and they do some ground strafing."

The P-51s do a fighter sweep over Ameins on Dec 5th and 2 squadrons also escort B-17s from the French coast to Paix France (about 1/2 way from the coast to Paris) Where P-47s take over for the rest of the mission.

Dec 13 sees the first long range escort done by P-51s, they use 75 gallon drop tanks and help P-38s of the 55th Ftr.Grp. escort bombers to Kiel, Bremen and Hamburg. Total of 1462aircraft, 710 are bombers. 46 are P-51s. Majority of the escorts are probably P-47s seeing as how back on Oct 15th the 55th Ftr.Grp. was declared operational while there were 9 fighter groups operational on P-47s.

You're saying nobody thought to put a drop tank on a jug before Feb 44?

Please show me where I said or wrote that? As most of us know they had been putting drop tanks on P-47s since the summer of 1943.
However there were a lot of problems with the early tanks and the P-47 needed a lot of fuel to fly very far. A single 75-110 gallon tank wasn't going to come close to doing the job. They went though a lot of lash-ups and experiments while they sorted out a large combat capable belly tank and engineered, manufactured and fitted the fuel lines, valves, fittings for the under wing tanks, which I already said in this thread they started fitting to planes already in England (in theater) in Dec of 1943, it just takes time to refit hundreds of aircraft on active fighter bases.

I'm still hearing denial that range was the biggest problem of the jug.

Not from me, the Jug did have a range problem, however it was solved, somewhat, about the same time the P-51 was being issued to the fighter groups of the 8th Air Force so it is sort of moot. From an operational point of view the fact that the P-51 could fly 700 miles on 419 gallons of fuel compared to a P-47D-25 flying 600 miles on 670 gallons means it is much easier to supply hundreds of P-51s compared to a like number of P-47s. Now please note I have said nothing about or in no way implied that the P-47 was the equal of the P-51 in air to air combat in any of the above.

 

[mad_max]

Carboncrank

You know I've learned much from the gents on here and I'm sure they've learned from my posts also. We don't always agree and I can be blunt at times. I don't like to speak verbal garbage, so I tend to tell it like it is. Some wrong facts were posted and all I did was post what I know. I don't just pull stuff out of the air when I post things. Maybe I have faulty data or such and then I get corrected. That's how things work here.

I've spent the better part of 35 years on studying WW2 aircraft, esp. fighters. I've been involved in data for sims since before the internet and am still involved with one today. I started doing this all the way back when Air Warrior was played on a BBS. Back then my state of the art computer was a Mac SE30 13" monochrome with a whopping 30 mhz processor.

Do I know everything? Not a chance. That's why I come here. Get off the horse you're riding and take a deep breath. The people here are great and you will learn more than you can ever believe.

I have never stated there were P-47's in service that could go 500mph. Sorry if I led you to believe I did. I also didn't say the Jug was the best fighter; although it did put many top notch German Fighter Pilots out of the picture before the P-51 B/C ever made a sortie in combat. My choices would be the P-47 for ground work, the P-51 for long distance escort and for pure fighter vs fighter a Spit IX or Spit XIV.

Since you want supporting evidence I googled P-51 laminar flow wing and this link was the second that came up. I have books and magazines that come to the same conclusion. I'll continue with the other corrections later if you so desire.

Here's some links for your perusal.

https://crgis.ndc.nasa.gov/historic/XP-51_Mustang
Laminar Flow Airfoil

For data you can't beat Mike's sight for loads of it.

WWII Aircraft Performance


Have a great day!

ABL

The North American P-51 "Mustang" is one of the best known fighter aircraft of the Second World War. Much has been written about the advantage in performance of the P-51 compared with other contemporary fighters by using a laminar flow airfoil. Its spectacular performance combined with excellent flying qualities and a very long range made it the best propeller driven fighter airplane of the war. The designer of the P-51 was Edgar Schmued, perfectionist and chief designer at North American Aviation. It was his intention to build an exceptionally clean aircraft showing the same aerodynamic characteristics like the smooth wind tunnel model. When in early 1940 the NACA first released information on the new laminar flow airfoil, Schmued decided to incorporate this new airfoil into the design of the P-51. The laminar flow airfoil promised about 20% less drag than conventional airfoils.

The introduction of the laminar flow airfoil into the P-51 design was observed with interest by the NACA. But NACA engineers expressed serious doubts concerning the performance of the laminar flow airfoil under real flight operations. Manufacturing irregulations, surface roughness and dirt would reduce the laminar flow to only a small region near the leading edge. The conditions of a highly polished windtunnel model could not be maintained on a real aircraft.

Nevertheless reports from England, where the NA-73 was flight tested, were very favourable with respect to the performance of the new fighter. RAF flight test engineers were convinced that the laminar flow had been achieved. But RAE scientists at Farnborough were very sceptical that the laminar flow airfoil was the key to its performance. They shared the doubts of their NACA colleagues. To find out what was that all about the US Material Command at Wright Field sent Dr. Edward P. Warner over to England. Warner's report was not conclusive with respect to the influence of the laminar flow airfoil on the performance of the NA-73. But he warned that the Germans could build aircraft of similar performance after a "Mustang" had got into German hands and the secrets of its laminar flow airfoil are disclosed.

But the fears of Dr. Warner were unjustified. At that time German scientists (Schlichting, Tollmien, Kawalki) had found a new way, to calculate the point of transition of the boundary layer from laminar to turbulent for compressible flow. This opened the way for the development of a new series of high-speed airfoils with superiour characteristics. First application was on the Messerschmitt Me 262 jet fighter.

In spite of that, the German aeronautical scientific community was interested in airfoils with laminar flow characteristics. Prof. Hermann Schlichting of the Technical Highschool Braunschweig did a lot of theoretical and experimental work to find laminar flow airfoils which would maintain its characteristics to very high Reynold Numbers. He investigated laminar flow airfoils of Russian and Japanese origin. It was the opinion of the scientific community that the laminar flow would disappear with increasing Reynold Numbers. The problem was that there existed no wind tunnel which could produce speeds high enough to come into the region of real flight Reynold Numbers (Re > 20 million) in order to prove the assumptions.

When the first P-51 Mustangs appeared over Germany in spring 1943, the good performance of this aircraft was well noticed. There were rumours that this aircraft had a laminar flow airfoil. Early in 1943 the German Air Ministry (RLM) provided an original P-51 wing in a good shape for further investigations. The AVA Göttingen measured pressure distributions at several wing sections and made drag measurements. The latter resulted in a surprising low profile drag. At this point Prof. Schlichting became interested. The same wing was put into the large 8 m wind tunnel A3 of the Luftfahrtforschungsanstalt Braunschweig-Völkenrode (LFA). It was Schlichting's intention to make boundary layer measurements and to estimate the point of transition on the airfoil where the air flow changes from laminar to turbulent. Measurements allowed Reynold Numbers up to 7,6 millions.The wing was carefully smoothed and a new coat of paint was applied. A problem was the position of the main spar where the wing surface had a small gap at ca. 25% depth.

The mesurements using a special probe which had to be moved very close to the surface were difficult. The slightest damage of the paint after the probe had touched the surface caused an immediate transition of the air flow from laminar to turbulent. The measurements were repeated for different Reynold Numbers and different lift coefficients. For the lowest Reynold Number (4 millions) the point of transition was measured at 50% depth on the upper surface. It moved to the leading edge with increasing Reynold Number, arriving at 20% for Re=7,5 millions. Measurements with different laminar flow airfoils including the Mustang airfoil were later continued in the large high-speed wind tunnel of the DVL, Berlin up to Reynold Numbers of 20 millions. These measurements clearly revealed the fact that the laminar flow effect completely disappeared at real flight Reynold Numbers. This was an expected but sobering result.

One important result of the wind tunnel investigations on the original Mustang wing was its low profile drag. This lead to a comparison of the Mustang wing with wings from different German aircraft. In 1944, rather late in a war, comparative wind tunnel measurements were made with original wings of the Fw 190, He 219, He 177, Ar 234, Me 109 F, Ju 288 and Martin B-26 "Marauder". Objective of these measurements was the estimation of the profile drag for different lift coefficients. These measurements revealed a clear advantage of the Mustang wing. Compared with the ideal smooth wing (wind tunnel model), the wings of the German aircraft had up to 60% higher drag than the ideal smooth wing. This reflects the poor manufacturing standards in Germany at that time. The Mustang wing had by far the lowest profile drag that could not be explained with the laminar effect alone, but to a large extent with the very good manufacturing standards at NAA.

Concluding you can say that the performance of the Mustang could not be attributed to its laminar flow airfoil. It was the overall low drag design of this aircraft with clean surfaces including the careful design of the radiator that was the key of its good performance. Edgar Schmued succeeded to build an aircraft as clean as the wind tunnel model - a remarkable aircraft and a remarkable designer.

References

1. Ray Wagner: Mustang Designer Edgar Schmued and the P-51. Smithsonian Institution Press: Washington D.C. / London 1990.
2. James R. Hansen: Engineer in Charge, A History of the Langley Aeronautical Laboratory 1917-1958. The NASA History Series. NASA: Washington D.C. 1987.
3. Breford / Müller: Messungen am Originalflügel des Baumusters P-51 "Mustang". AVA FB. Nr. 1724/2, 1943.
4. Kopfermann / Breford: Umschlagpunktmessungen am Originalflügel des Baumusters P-51 "Mustang". In: Deutsche Luftfahrtforschung, UM 2035, 1943.

 

[DerAdlerIstGelandet]

a lot easier to dis me than to make a counter argument isn't it?

There is no correct answer to a question with incorrect facts. There is no right answer to " how in the world does a P-47 have any business having a top speed of 500+ MPH" because P-47's did not fly 500+, yet posters were trying to answer it anyway.

I did something I don't see hardly anyone on her do. I gave sources. Not just any clickbait sources, the best ones I know.

Facts don't care if they are popular. In fact, the notion that popular is more important than being right is the root of the current problem in the White House. Social media is target rich for con artists and manipulators.

I also did something I don't see much of. I admitted and error. I went on to point out the correct number didn't change my point, but I admitted the error. I didn't dance around it or ignore it or continue to claim it's true like our current President would do.

So, in your case it wasn't enough to hit dislike, you had to tell me and justify it by saying some mumbo jumbo about faulty this and that, that you can't be bothered to explain, but you are sure to point out you don't think I'm friendly enough.

I don't care.

Whether my position on the topic is the "correct" one has nothing to do with the manner in which it's delivered. I care more about clear-eyed skeptical analysis and what the truth is far more than I do whether I'm popular.

The emphasis on making everything a popularity contest is the facebook way of life. And THAT has the world up to it's neck in fact facts, fake news, and lies propagated by people that know how to manipulate algorithms. That is how the Russians got Donald Trump elected. Fake news, falsehood and propaganda shoved further and further up the rankings because someone hits the "like" button in a worlds where people care more about what their friend believe than they do the truth. The internet was invented for searching factual data. I use it all the time so I don't say stupid stuff. Social media is a perversion of that intent. People raised in a world where the internet has always been their have become astoundingly lazy about using it for what it was intended for. So I see more and more stupid stuff.

I don't know how the original poster got the 500mph plus notion, but I know where they didn't get it. They didn't get it through actual data on the craft. More likely they think they remember someone posting it online in some other discussion. Fact checking? Who needs it right?

I think you should point out where you think I'm wrong and save you judgments about my personality to yourself or make them in private.

If this forum turns out to be a clique it won't stop me from posting about something I'm passionate about and know a lot about and can back my notions with facts, for the most part. None of us is free of point of view bias of some level. I work very had to challenge bais in my own thinking. If I was going for a bias point of view I'd ague the Hellcat as the best combat aircraft. My father flew them off aircraft carriers.

And we do not allow any modern political discussion of any kind on this forum.

Go and read the forum rules. This will be the only warning on the topic of politics.

Posting modern political discussion, regardless of what side of the fence you are on, can and will get either a thread closed or a poster removed (temporarily for a first offense) if they can not abide by the forum rules that are posted. Please respect the forum rules, especially regarding politics and civil discussion. I have posted links to two threads regarding forum rules.

A few ground rules for the new folks

The Thread to end All Political Threads (Hopefully)

I do get the point though and will try and refrain from politics even though I was talking about a mindset more than a person regardless how I feel about people's behaivoir on the internet to be linked to the situation we find ourselves in now.

You will not try and refrain, you will refrain...

Not trying to be an asshole here, but modern politics has 0, zilch, nada, nothing to do with this topic, and this forum has a 0 modern politics rule in place anyhow.

 

[DerAdlerIstGelandet]

And to all members posting in this thread. Please do so in a civil and respectful manner.

 

[Shortround6]

We may have some confusion as to what the "original premise" of this thread is.

I could be wrong (it's happened plenty of times before), but I took it as a general question as to why some rather large, heavy aircraft were as fast or faster than some smaller, lighter and more streamline appearing aircraft. I believe that question has been answered by the replies concerning power and drag at altitudes.

Now perhaps the examples given for the bulky fighters were not the best possible ones (may depend on your point of view) as they were either prototypes or late/post war versions built in limited numbers, but I don't believe that invalidates the basic question.
The XP-47J is supposed to have flown at over 500mph. Perhaps only once or twice? Perhaps never? Depends on which stories you believe. However this prototype does show up along with the 500+ speed in practically every book or long article about the P-47 and so is widely known.

And yes it is far, very far, from a standard P-47. However stuffing the same basic powerplant in a P-47D airframe did get you the P-47M version (100 built) and 470mph which I figure is close enough to ask how they did it compared to even a P-51H which was a bit faster on a lot less power.

I don't believe anybody in this thread has been arguing that normal production P-47s of 1943/44 could do 500mph or even 450mph.

I do believe that people who want to argue about the technical aspects of aircraft would do well to use better sources than Acepilots.com. a nice "quicky" look at a plane but hardly detailed (like the common error of not giving the altitude at which the speed was achieved)

 

[drgondog]

Couple of notes;

• XP-47J flew 505mph at Republic
• XP-51G flew 498mph at NAA
• Neither flight tested by AAF, nor in any certified closed course.
• First Operational P-51B mission was by 354FG led by Don Blakeslee on December 1, 1943. Standard 'Newbie break-in' Area Patrol over French Coastal area.
• P-51B-1 and early P-51B-5 did not have factory pressure pump installed at factory and all were modified at Warton BAD2 until the mid P-51B-5 block 43-67XX (have to look up). Ditto P-47C and early P-47D. Haven't yet confirmed first 75 gallon auxiliary tank mission. Bremen on 12/10 is a possibility. Bordeaux on 12/31 is a certainty. The 200 gallon ferry tank was tested with first exhaust pump modified at 8th Svc Cmd in July 1943, but the 200 gallon tank was replaced with the 75 gallon, then 108 gallon C/L tanks in August, 1943.
• P-51B-10 (#1 43-7113) first factory 85 gallon tank. P-51B-1 43-12112 was modified with steel fuselage fus tank (~92 gallons) and flown by Chilton on July 16, 1943. AAF Flight Tests in 43-12305 during first two weeks of August.
• 1200 85 Gallon Kits (complete) were shipped from NAA to both stateside Base Depots and BAD2 Warton. The first kits were applied to P-51B-1 in UK in December. The first 85 gallon kit installed on P-51B-5 in the States (as near as I can find) was 43-6382 at Buffalo Base Depot. All succeeding P-51B-5 through 43-7112 were modified in the US.

Not even NAA called the NACA/NAA 45-100 Laminar Flow. It's primary features were a.) very low drag and b.) delayed Mc by virtue of max T/C at 45% C and low velocity gradient from zero to 45% C when compared to NACA 23xxx (P-38, F4U, F6F, FW 190, etc)
Laminar Flow to Turbulent Flow transition is RN~ 500,000 (0.5x10^^6) (taxi speed). The key to the 45-100 is that the adverse pressure gradient due BL separation was delayed.

Induced Drag at top speed is about 0.75% of Total Drag for a P-51B, less for the P-47 due to higher Oswald efficiency of wing. CLARIFICATION - The % contribution of Induced Drag to Parasite Drag increases over baseline when weight is added. It is a function of CL and AoA which must increase when more weight is carried by the wing. The figures provided were for P-51D when weight was added over P-51B normal combat load.