Top Five fighters of WWII and why

[Northern Neil]

Maybe the Spitfire was marginally best on it's introduction, but even the later enhanced versions probably ranked below the top all time 5.

Hmm... P51d yes, FW 190 maybe, P47 debateable, Vought Corsair debatable. Which other piston engined fighters outperformed the Supermarine Spitfire?

[caldrail]

In what respect? Fighter aircraft are exercises in compromise between various factors such as speed, agility,climb rate, firepower, maintenance, durability plus many others. A plane cannot be best at all of them. Let's face it, in terms of charisma, there is no fighter than can match the Spitfire. Heck, we won the Battle of Britain because we had the best looking aeroplane

[caesar novus]

Hmm... P51d yes, FW 190 maybe, P47 debateable, Vought Corsair debatable. Which other piston engined fighters outperformed the Supermarine Spitfire?

I am more of a Hawker fan, so permit me to mudsling. The Supermarine Spitfire was an expensive short ranged racehorse that would have been inadaquate on it's own, but served well in smaller numbers to defend Hawker Hurricanes that were doing the real bomber interception work. I say inadaquate because frills like the eliptical wing took forever to construct, which would reduce producable aircraft numbers. Also the sleek design didn't accommodate heavy upgrades in weapons and engines easily, and I hear later fast models maneuvered poorly. In spite of it's short range, I recently heard that it was a couple of Spit's that strafed Rommel's car in France - good show!

 

I'm not saying the Hurricane was better, but oh man, have you seen the Hawker Tempest 2 in the north London museum? Not the models with droop intake but the svelte ducted-radial, like an Fw-190 mated with a Spit. It had great promise, but never got the chance to be fully debugged by war end. Also what about the similar macho design Hawker Sea Fury, which not only carried over to Korean war but apparently played a big role in Castro defending Bay of Pigs 1961. OK I realize these aren't WW2 battle tested (as I was about to bring up the Fiat G55 which Kurt Tank supposedly liked enough to recommend replacing his Fw190).

 

I've seen the Corsair do mock battle with a Mustang and it was so utterly dominant that I wonder if it was more than just pilot differences. Both were uninteresting until late war refinements, then they flew in different theaters. I do realize an early version of Corsair was flown by England, and don't recall how they rated it besides wresting with the carrier landing quirks. So the Spit may have been top dog early on, but by late war I think Corsair, Mustang, and maybe a long nosed or long tailed Focke Wulf were stronger contenders.

[caldrail]

There were some BoB veterans who state they preferred the Hawker Hurricane largely because it was a sturdy and stable gun platform.

 

The Hawker tempest was developed interestingly enough as part of a program to find a replacement for the Hurricane. The sister design, the Tornado, never progressed very far, but the typhoon entered service and was found to be a flawed design which was better suited to an attack role. The Tempest was an attempt to improve on that and in a sense, restore Hawkers reputation as a designer of front line fighters, though in the event it was also used in an attack role. The radial version, the Bristol Centaurus powered Tempest II, was intended primarily as a pacific theatre fighter that would have been part of Britains 'Tiger Force' sent east after the cessation of hostilities against Germany. in any event, it was liekly the aeroplane would have been succeeded by the Hawker Fury in both land and naval versions had the conflict persisted.

 

The reason the Corsair made a poor start was down to its origins as a naval fighter and the demanding nature of the design for shipboard operation. The US Navy initially thought it was dangerous and foisted the production of early examples onto the Fleet Air Arm (who proved the design could be used effectively) Only later, with British and US MArine experience, was the fighter better utilised.

 

The Mustang was a longer range fighter with excellent energy retention characteristics, and often quoted as the best all round fighter in WW2, but as I understand it the contemporary spitfires still had a tighter turning circle. It is remarkable for a fighter initially designed as a commercial competitor to the P40 for the european market at short notice, that it proved to be such an adaptable and capable design.

[caesar novus]

It is remarkable for a fighter initially designed as a commercial competitor to the P40 for the european market at short notice, that it proved to be such an adaptable and capable design.

Well, some say the laminar (non turbulent) flow airfoil design did the trick but others say laminarity was lost the moment you hit some insects or raindrops. Others claim the oil cooler cancelled out it's drag with a bit of hot air thrust vs. much draggier competing designs. But it was really key that Mustangs needed the British engine upgrade or else it was mediocre.

 

So I speculate that the Corsair maybe should be the unsung hero American design. It packaged the same monster radial engine in a much sleeker package than the bloated P-47. The P-47 was eccentrically optimized around an efficient turbocharger in it's tail, which required huge internal air ducts going back and forth. Yet it didn't really need to sacrifice everything for high altitude - it became a ground strafer.

 

The Corsair had more problems than poor landing visibility - there was some scary aerodynamic pitfalls that were only cured late (sudden spins?). After that I think it became awesome, at least in the hands of an expert. I could barely believe my eyes watching a demo flight (I have been an airshow fanatic for decades and soloed at age 15). A possible clue for it's downplay came from a pilot interview who said he felt safer in the Hellcat. That is a low performance aircraft, but maybe adaquate for the weak competition near end of war... and built like a tank so an oversight of enemy on your tail wouldn't end your prospects of going home alive.

 

But the radial Corsair was more survivable than either Mustang or Spitfire in the other theater of war. And let's not overlook other issues like the crude flight computer of FW190. I believe the throttle had fancy linkage to something like mixture or prop pitch or some other controls. Then you could slam it forward when spying the enemy, vs a bunch of fiddling in other aircraft that could result in you missing sight of the opponent before reving up. I think one of the last stretched Fw models (but before the Ta152) was a good contender.

 

To me the pretty elliptical wings on the Spitfire were kind of a gimmick. It's well known that is the best aerodynamic shape, but at what cost? You could replace the awkward inverted gull wings on a Corsair with sleek ellipticals, but maybe you would then have to remove a lot of fuel and replace the 50 calibers with 30 caliber (deer rifle category) that the early Spit's had.

 

But based on being the right tool at the right time, I might have to concede the Spitfire won WW2. That if I extrapolate from a video by (eccentric?) historian John Lukacs at http://www.booktv.org/Program/11432/The+Legacy+of+the+Second+World+War.aspx IIRC he says the Pacific theater was a sideshow and Japan never had a chance. And that Stalin admitted he couldn't conquer Germany on his own - only eliminate German expansion. German conquest required USSR plus USA (esp it's supply donations) but not the UK. However, UK played an essential role in not "losing" the war to Germany early on. And while Hurricanes had a high bomber kill count, all may have failed if there weren't just enough Spitfires with enough performance edge to keep fighters from mauling the Hurricanes

Edited August 21, 2011 by caesar novus

[caldrail]

It is remarkable for a fighter initially designed as a commercial competitor to the P40 for the european market at short notice, that it proved to be such an adaptable and capable design.

Well, some say the laminar (non turbulent) flow airfoil design did the trick but others say laminarity was lost the moment you hit some insects or raindrops. Others claim the oil cooler cancelled out it's drag with a bit of hot air thrust vs. much draggier competing designs. But it was really key that Mustangs needed the British engine upgrade or else it was mediocre.

Aaargh! There is no thrust from the radiator efflux whatsoever. Quite the reverse. The advantage, as recognised by the designers of the 1938 Napier-heston racer, was that a radiator in such a position produced cleaner boundary layer air under the rear fuselage and thus that reduced drag.

 

So I speculate that the Corsair maybe should be the unsung hero American design. It packaged the same monster radial engine in a much sleeker package than the bloated P-47. The P-47 was eccentrically optimized around an efficient turbocharger in it's tail, which required huge internal air ducts going back and forth. Yet it didn't really need to sacrifice everything for high altitude - it became a ground strafer.

No. The position of the turbocharger wasn't uncommon in those days. The P38 fitted theirs in the tail booms. The german BV155 design has huge intakes in the mid-rear fuselage for this reason. It's a matter of engineering a turbocharger large enough to boost an aero engine of 20 or 30 litres in capacity and still balance the airframe. Also the P47 wasn't as aerodynamically bad as you suggest. It was a very fast aeroplane that was able to dive away from german fighters.

 

The Corsair had more problems than poor landing visibility - there was some scary aerodynamic pitfalls that were only cured late (sudden spins?). After that I think it became awesome, at least in the hands of an expert. I could barely believe my eyes watching a demo flight (I have been an airshow fanatic for decades and soloed at age 15). A possible clue for it's downplay came from a pilot interview who said he felt safer in the Hellcat. That is a low performance aircraft, but maybe adaquate for the weak competition near end of war... and built like a tank so an oversight of enemy on your tail wouldn't end your prospects of going home alive.

The Hellcat was not a low performance aeroplane. It was a frontline fighter for the second half of the war. Stall characteristics are sometimes a bit scary in aeroplanes of that generation, some behave better than others, but I do accept the Hellcat was a 'frendlier' aeroplane to fly - not such a bad characteristic even in war.

 

But the radial Corsair was more survivable than either Mustang or Spitfire in the other theater of war. And let's not overlook other issues like the crude flight computer of FW190. I believe the throttle had fancy linkage to something like mixture or prop pitch or some other controls. Then you could slam it forward when spying the enemy, vs a bunch of fiddling in other aircraft that could result in you missing sight of the opponent before reving up. I think one of the last stretched Fw models (but before the Ta152) was a good contender.

There was a flight computer of a sort in the FW190 which was designed to take some of the work out of handling the engine and as I understand it worked just fine. Anything that keeps a pilot from being occupied with stuff inside the cockpit can't be a bad thing, surely? I agree. The Ta152 was a step up and a serious contender over the skies of Germany but for a lack of fuel, parts, and pilots.

 

To me the pretty elliptical wings on the Spitfire were kind of a gimmick. It's well known that is the best aerodynamic shape, but at what cost? You could replace the awkward inverted gull wings on a Corsair with sleek ellipticals, but maybe you would then have to remove a lot of fuel and replace the 50 calibers with 30 caliber (deer rifle category) that the early Spit's had.

Every fighter is an exercise in compromise to achieve a desired result. RJ Mitchell certainly had an eye for a beautiful design, but a gimmick? No, I doubt Mitchell was thinking in terms of gimmicks. He was aiming to create an efficient fighter for the RAF and incorporated what he considered the best cutting edge features. The spitfire wing is known to be very efficient. Even at 60mph a pilot needs to be wary because his plane can readily float on landing.

[caldrail]

Regarding thrust from a P51 radiator, this a common urban myth caused by a misunderstanding (or complete ignorance of) the physics and engineering involved. There's a lot of such myths floating around at the moment unfortunately.

 

Liquid cooled engines transfer heat generated by combustion and friction via the coolant to the radiator where the heat is allowed to escape the system. In effect, this transfer of heat therefore occurs twice. The coolant circulates in the sytem so the heat does not boil the fluid - which renders the cooling system temprarily inoperative - and the fluid is exposed to moving air in the radiator to get rid of that heat by 'wind chill'.

 

Think about that. If you stand in a strong wind, the movement of air past you will cool you down. There is no thrust moving you into wind, and in fact, the wind is forced to go around you, thus causing pressure and a static 'drag' effect.

 

It's no different for radiators. They stand in the way of airflow and cause drag. The air passing through is warmed momentarily and continues on its way. The amount of heat carried off by each molecule is not huge but the total effect is a lifesaver for engines. For this reason however there is no rapid expanison of air, because the amount of warming is slow and uncontained. Therefore there's no pressure other than the airflow pushing through thus no pre-explosive expansion to create thrust.

 

I know it's sometimes quoted that exhaust pipes are angled backward to produce a measure of thrust. That's correct. A small amount of air and volatile fuel mixed together in a confined space creates a lot of pressure when ignited, so much so that it pushes a piston that turns a crankshaft that rotates a propeller that makes an aeroplane go. So inevitably, the expansion rate of combusting fuel/air is enough to cause a small amount of thrust when sent back through a directed exhaust.

 

In other words, the only way to get thrust from a radiator is to dump fuel into the back of it and ignite it. But if you do that, how does that cool the engine? If you find that your radiator is creating thrust, I would recommend you consider leaving the aeroplane as soon as possible because in that hypothetical situation your engine has but minutes to live.

[caesar novus]

In other words, the only way to get thrust from a radiator is to dump fuel into the back of it and ignite it.

It is called the Meridith effect, and was apparently introduced in the Spitfire http://en.wikipedia.org/wiki/Meredith_Effect . Same principle as a nuclear thermal rocket - apply a heat source to incoming fluid and expel the expanding fluid in a way that provides some thrust without stagnanting the incoming fluid flow. I think some confusion comes from sloppy wording that implies oil coolers provide NET thrust rather than a partial offset of the vent's drag. I speculate that the Spitfire offsets a tiny part of the oil cooler drag, and the Mustang offsets a small amount.

 

The position of P-51 oil cooler always bothered me because it creates the worst possible "area rule" for transonic drag. The cooler vent coincides with the wing and canopy in a cross sectional view, and maybe restrict the max dive speed due to max pressure-wave creation. Is it the Spitfire that has that weird assymetrical cooler location under one wing (or Hurricane)? Seemed strange to me until I thought it might help to balance torque by countering yaw. Sort of like that weird Nazi (B&V?) plane with engine on one side and cockpit on the other - I think they put the draggy part to port which balanced propeller torque.

 

As for the mighty but unloved Corsair, I only consider it a contender in the last year of the war when they fixed a scary assymetric spin/stall pitfall with what wiki describes as "These potentially lethal characteristics were later solved through the addition of a small, 6 in (150 mm)-long stall strip to the leading edge of the outer starboard wing". Before then it had an accident rate many times that of combat losses. By the last year, surely you gotta consider Hellcat as an old duffer - oddly it was hardly changed from it's early introduction yet had a huge kill rate. Oh, that reminds me the Bearcat could be argued as best prop fighter. But the corsair was still used in combat as late as 1969 (shot down a mustang), while Spitfires were pulled out of combat patrols in 1954 (unlike Sea Furies).

 

Turbocharger locaton was the rear in P-47 IIRC, as opposed to more midpoint for P-38. I wish I could find again an amazing semitransparent color coded drawing of the P-47 ductwork, wrapping around the pilot and under the wings to and fro. They were very wide ducts in order to create free flow efficiency. Air came into the cowling which was extra large for this (unlike the Corsair which sipped it's tc/oil air thru wing inlets). Massive ducts brought air to rear for compression, then returned all the way forward to feed the engine. The engine expelled this air into exhaust piped to the rear to power the turbocharger - three lengthwise trips! All for ultimate high altitude performance that wasn't needed. Ducts, etc gave a lot of pilot protection and weight for diving - I would be happy to experience it's great safety record during the war.

[caldrail]

In other words, the only way to get thrust from a radiator is to dump fuel into the back of it and ignite it.

It is called the Meridith effect, and was apparently introduced in the Spitfire http://en.wikipedia.org/wiki/Meredith_Effect . Same principle as a nuclear thermal rocket - apply a heat source to incoming fluid and expel the expanding fluid in a way that provides some thrust without stagnanting the incoming fluid flow. I think some confusion comes from sloppy wording that implies oil coolers provide NET thrust rather than a partial offset of the vent's drag. I speculate that the Spitfire offsets a tiny part of the oil cooler drag, and the Mustang offsets a small amount.

The effect is insignificant. Unfortunately for fans of jet mustangs, there's something called thermodynamics which gets in the way. Part of that is the fact you cannot get something for nothing. In order to provide thrust you need to supply energy in such a way as to push the aeroplane forward. The whole point of a radiator is to get rid of that heat. There is no function of a radiator that mysteriously pushes an aeroplane forward. If you ran a mustang on the ground without a propellor, I guarantee it won't go anywhere. Quite why anyone imagines a P51 has anything in common with a nuclear thermal rocket is beyond me.

 

You have to understand that over the last few decades there's been a lot of re-invention of world war two aeroplanes fuelled by sensationalist reporting particularly on television, whose authority on technical subects usually borders on the laughable. But this meredith effect? Put your hand in front of your face and blow on it. Not diifcult I guess, and you feel the impact of moving air on your hand. Now do the same but blow down a drinking straw. The air definitely feels like it's a more powerful draught doesn't it? Strictly speaking, it is. However you might want to note how harder it is to blow down the tube and that the overall effect is is limited in scope, and in the case of the P51 does not provide any measurable net thrust compared to the backdraft of the propellor and instead does what I said it did in the first place, reducing drag by forming a boundary layer control under the rear fuselage.

 

The position of P-51 oil cooler always bothered me because it creates the worst possible "area rule" for transonic drag. The cooler vent coincides with the wing and canopy in a cross sectional view, and maybe restrict the max dive speed due to max pressure-wave creation. Is it the Spitfire that has that weird assymetrical cooler location under one wing (or Hurricane)? Seemed strange to me until I thought it might help to balance torque by countering yaw. Sort of like that weird Nazi (B&V?) plane with engine on one side and cockpit on the other - I think they put the draggy part to port which balanced propeller torque.

The P51 wasn't designed for transonic speeds. No-one in 1941 knew anything about transonic flight or even if it was possible. The spitfire has two underwing coolers in the early versions but I understand they cool different things and the assymetric aspect was a solution to aerodynamic and engineering compromise. As for the BV155, the position of the intakes had nothing to do with torque whatsoever. It's an engineering issue. They were present on both sides afterall.

 

By the last year, surely you gotta consider Hellcat as an old duffer - oddly it was hardly changed from it's early introduction yet had a huge kill rate. Oh, that reminds me the Bearcat could be argued as best prop fighter. But the corsair was still used in combat as late as 1969 (shot down a mustang), while Spitfires were pulled out of combat patrols in 1954 (unlike Sea Furies).

The Hellcat was still a capable aeroplane in 1945 if not a podium finish anymore, such is the progress of performance. I would like to point out that removal of a type from service removes those airframes from action, and unless you can have better replacements available, you have no choice but to contiue using the older ones. In any case, the Hellcat was not regarded as a poor design, and remained competitive at the end of the war because it was still flying against older japanese aircraft. The japanese were never able to supply their newer and more capable aeroplanes wholesale.

 

All for ultimate high altitude performance that wasn't needed. Ducts, etc gave a lot of pilot protection and weight for diving -

High altitude performace is necessary if the enemy are going to fly higher than you. Further, as an escort fighter, high altitude performance was necessary to protect high flying bomber formations. Further, air begins to thin appreciably from 8000ft above sea level thus to be competitive at twice that height, the only way to derive maximum output from an engine was to supercharge it in some way, and the P47 employed turbines for that purpose. Ducts do not provide any particular protection for the pilot being built of sheet metail which is easily penetrated by cannon rounds. Weight means very little regarding dive performance since the aeroplane is accelerating faster than gravitional pull.

[caesar novus]

I forgot all about sea furys and Tempests, assuming we were talking best piston engined fighter of WWII - although I concede, the Tempest did see limited action before May '45. Typhoons I believe were a bit lacking in manoevrability compared to the Mk. XIV Spitfire. When I was at Duxford last year, the fighter that impressed me the most was actually the P47. Chunky body, 12ft. prop and massive radial enginne - its just a no nonsense beast that, with its eight .50 Brownings, could knock a steam engine off its tracks.

The BBC quote in question is: "The Spitfire is one of the most vaunted examples of British engineering's history. The greatest ever single-seat, piston-engined fighter, it had played a vital role during the Battle of Britain the year before." No restriction to WW2, although how do you prove greatness without that test. No distinction of interceptor vs ground attack vs escort fighter, although how to compare between classes. So we can't get overly serious about it, but fun to brainstorm.

 

I think Duxford has US planes all sequestered in one hanger, with so much metal polish they seem like showpieces rather than warbirds. The Hendon RAF museum (alight at Colindale, not Hendon London underground stop) has a P-47 right next to a Tempest2. That Tempest2 stole my heart, even though my head favors P-47 as what I would have done best with. Tempest2's tight radial cowl using ducted fan for cooling is so, er, cool. First on the Fw190, then picked up by Hawker, and even attempted once on a post war P-47 (looked silly) - I think it was the ultimate answer for piston technology.

 

P.S. I may have an anti eliptical bias vs the Spitfire because an acquaintance of mine terrorized the paragliding industry in early 1990's with his patent on eliptical canopies. I think it is an obvious ideal shape based on physics that shouldn't be patentable, but simply used as the default if you don't have important other issues driving the design. I heard he had initial success in getting some fat royalties, but I suspect his claim since fell apart. Some late model Spitfires departed from elipticality.

Edited August 22, 2011 by caesar novus

[caesar novus]

The effect is insignificant. Unfortunately for fans of jet mustangs, there's something called thermodynamics which gets in the way. Part of that is the fact you cannot get something for nothing. In order to provide thrust you need to supply energy in such a way as to push the aeroplane forward. The whole point of a radiator is to get rid of that heat. There is no function of a radiator that mysteriously pushes an aeroplane forward. If you ran a mustang on the ground without a propellor, I guarantee it won't go anywhere. Quite why anyone imagines a P51 has anything in common with a nuclear thermal rocket is beyond me.

Significance: I said that some claim there was a bit of thrust. A bit, as in cancelling out the drag of a few rivets. Typical thing that raceplane designers do to just get that 1mph edge at any cost. Like eliptical wings - sounds like Meridith-chasing originated at Supermarine and was foisted onto North American during the Brit P-51 order.

 

Fanhood: I called P-51 a tiresome candidate, beloved by many so at least needing discussion. I don't like it, but respect it. A long p-51 evaluation in Smithsonian Air&Space magazine was not entirely glowing, but I have long lost it. I recall they did the same for the Zero and punctured some myths there to - the designer didn't intend for such a light fragile craft but was driven to desperation when the original engine proved weak.

 

Meridith: If you click on the nasa.gov footnote in my Meridith link, you would see pictures and discussion of 1941 electric powered "open-duct jet propulsion" (now called ramjet) which uses no combustion at all and becomes especially effective by mach .75. It ran at 300 degrees, but the temperature "difference" is key so maybe hot p51 oil in -50 degree ambient air at full combat speeds starts to get efficient. Another source claims measurable performance at one half mach, but like you say none at all at rest. As for the nuclear option, look up Tory-IIC nuclear ramjet which is simply an air pipe with hot uranium instead of combustion. In spite of proving itself for 5 minutes at full power, US green extremists squashed the dream of having those spewing overhead.

 

The P51 wasn't designed for transonic speeds. No-one in 1941 knew anything about transonic flight or even if it was possible.

This is a really famous issue for p-47 and p-38 in dives. You can see transonic dangers elaborated over many pages in the P-51 flight manual (link below), although it is called "compressibility". They basically say at 0.75 mach some of the air funnels over airframe bulges around mach 1.0 and you are going to die unless doing so and so procedures. They have many explanatory pictures if you scroll upwards, including how P-51 laminar type wing delays this critical mach onset vs all other aircraft. I speculate it's worst possible oil duct location may be the limiting factor. But I don't care what they knew - I am judging bestness not best effort. http://books.google.com/books?id=SfwqCTY9I6MC&pg=PA74&lpg=PA74&dq=compressibility+p-51&source=bl&ots=hOFFTwYSE_&sig=BHmEe5LoThoB6pcOdv6R7LRnqwE&hl=en&ei=hcZSTouCFeHliAL-rLBt&sa=X&oi=book_result&ct=result&resnum=7&ved=0CFcQ6AEwBg#v=onepage&q=compressibility%20p-51&f=false

 

The Hellcat was still a capable aeroplane in 1945 if not a podium finish anymore, such is the progress of performance. I would like to point out that removal of a type from service removes those airframes from action, and unless you can have better replacements available, you have no choice but to contiue using the older ones. In any case, the Hellcat was not regarded as a poor design, and remained competitive at the end of the war because it was still flying against older japanese aircraft. The japanese were never able to supply their newer and more capable aeroplanes wholesale.

 

If moved to the European theater I think the Hellcat would be hopelessly mauled, yet the (late-late model) Corsair might be king of all. Hellcat couldn't engage in normal dogfights - it's tactics relied on things like dive at the enemy then flee or the thatch weave. Japanese planes couldn't dive fast - light weight relative to drag gives a low terminal velocity hard to overcome without gobs of power. The Corsair packaged that massive 2000hp double radial in much sleeker, lighter, and more nimble package than similar engined p-47. I have seen it carve pretzels in the air yet speed away like a drag racer. It reminds me of seeing a canard equipped Saab jet demo - unbelievable maneuverability and straight speed. In the Corsair case, instead of canards they relied on pilots who could handle a difficult plane without easy stability.

 

High altitude performace is necessary if the enemy are going to fly higher than you. Further, as an escort fighter, high altitude performance was necessary to protect high flying bomber formations. Further, air begins to thin appreciably from 8000ft above sea level thus to be competitive at twice that height, the only way to derive maximum output from an engine was to supercharge it in some way, and the P47 employed turbines for that purpose. Ducts do not provide any particular protection for the pilot being built of sheet metail which is easily penetrated by cannon rounds. Weight means very little regarding dive performance since the aeroplane is accelerating faster than gravitional pull.

I can't find the reference now, but I read the P-47 extreme, over-the-top turbocharger wasn't deemed helpful in combat - they preferred lesser supercharged p-51 instead. I can't reference everything - maybe the Nazi competition wasn't turbocharged or suffered from their lower octane? It was far more bulky implementation than other turbos which only gave them diminishing returns. Anyway the p-47s shifted to low altitude ground attack. Here is a link below depicting the massive p47 ductwork and how it shielded battle damage and smoothed belly landings in actual experience (scroll up). http://books.google.com/books?id=Sq5pPTWlbqAC&pg=PA25&lpg=PA25&dq=p47+supercharger+ducts&source=bl&ots=mHYtOcTUIK&sig=d9trjkfU7gXs5JvQuduObGkXJJE&hl=en&ei=otBSToHdNOnUiAK0hMjuDA&sa=X&oi=book_result&ct=result&resnum=4&ved=0CDAQ6AEwAw#v=onepage&q&f=false

 

I seem to recall you were statistically almost safer flying a p-47 in combat than driving at home after a few beers on Sat night. The dogfights documentary series covered a p-47 under relentless attack that simply flew home while Germans emptied their magazines into him. I think a deflection shot could have penetrated the ductwork into the pilot, but it was hard to even see where the pilots body was in that huge mass.

 

I question weight not helping in power dives. Weight was a famous dive advantage in published tactics for large US fighters - even without power it tends to give you a higher terminal velocity. You are fighting a lot of drag even in a dive, so will need plenty of power to achieve that magical state of acceleration you would experience while falling in a vacuum. After that, weight would indeed detract your further acceleration, so maybe a little Storch can dive best of all? No, you may need to have power to weight ratio more than 1 to achieve that (thus can climb straight up without losing speed) which I don't think was the case.

Edited August 22, 2011 by caesar novus

[caldrail]

Significance: I said that some claim there was a bit of thrust. A bit, as in cancelling out the drag of a few rivets. Typical thing that raceplane designers do to just get that 1mph edge at any cost. Like eliptical wings - sounds like Meridith-chasing originated at Supermarine and was foisted onto North American during the Brit P-51 order.

I can see the phrase 'net thrust' is causing confusion. I would never use the term, it's inherently misleading and used out of context in many cases, especially by internet experts.

 

'Gross Thrust' (though no-one ever uses that term) is what the engine gives you. For all intents and purposes, it's a fixed value for our calculation. The engine will only give you so much thrust. That's the only source of impetus in straight and level flight. You cannot find anything else to push the aeroplane forward against inertia. So we'll simply call it 'thrust', yes?

 

By definition, 'net thrust' means the impetus left after losses are factored in, which means drag and so forth, because ineffeciencies in the engine are measured at the output end in which case are already factored in our thrust figure. Therefore, an increase in 'net thrust' is not added impetus, but a decrease in drag or external inefficincies which allow more of the 'thrust' to be effectively used. I recommend you ignore the term 'net thrust'. It's hugely misleading and remains an artifical concept.

 

This is a really famous issue for p-47 and p-38 in dives. You can see transonic dangers elaborated over many pages in the P-51 flight manual (link below), although it is called "compressibility".

It's called compressibility because that was all they understood. As speed increased an aircraft usually buffeted and broke up. They did not understand the aerodynamics of transonic flight and hadn't even invented the term to cover it. This sort of thing is typical of the nonsense I see posted about aeroplanes on the internet by people who have the benefit of hindsight and cannot discuss aviation without reference to modern aerodynamics and aircraft features. The Gotha 229 is regaularly described as a 'stealth fighter' now. Nonsense. Even if Reimar Horten believed the shape would deflect radar emissions (it wouldn't - that shape reflects radar like any other curved surface) or included charcoal in the glue to absorb radar (it wouldn't - the radar boubnces off the external surface and the wooden part of the airframe was restricted to the outer wing panels), these were likely to be retrospective comments quoted out of context. No-one was building stealth fighters in 1945 and note that no-one (including Reimar Horten) said anything about stealth technology before the phrase was regularly touted on the internet.

 

Whilst I'm not disputing the evident superiority of the Corsair, please bear in mind that the Hellcat socred 400 kills for 18 losses in the Marianas Turkey Shoot. It was also employed succesfully after WW2, and also employed succesfully against german and italian opposition in smaller numbers.

 

I can't find the reference now, but I read the P-47 extreme, over-the-top turbocharger wasn't deemed helpful in combat - they preferred lesser supercharged p-51 instead.

yet pilots of the P47 were very enthusiastic about their mounts. I think you might be quoting internet experts there.

 

Anyway the p-47s shifted to low altitude ground attack.

So did all the other US fighters toward the wars end. There weren't enough luftwaffe aircraft left to go around.

 

I seem to recall you were statistically almost safer flying a p-47 in combat than driving at home after a few beers on Sat night. The dogfights documentary series covered a p-47 under relentless attack that simply flew home while Germans emptied their magazines into him. I think a deflection shot could have penetrated the ductwork into the pilot, but it was hard to even see where the pilots body was in that huge mass.

Never ever believe anything you hear said on television documentaries. They are extremely suspect sources of information. In any case, a pilots vulnerability was hardly likely to be a point of target. Aircraft were targeted as a whole and what you actually hit depended on all sorts of factors, whivh is why pilots were taught to get up close.

 

I question weight not helping in power dives. Weight was a famous dive advantage in published tactics for large US fighters - even without power it tends to give you a higher terminal velocity. You are fighting a lot of drag even in a dive, so will need plenty of power to achieve that magical state of acceleration you would experience while falling in a vacuum. After that, weight would indeed detract your further acceleration, so maybe a little Storch can dive best of all? No, you may need to have power to weight ratio more than 1 to achieve that (thus can climb straight up without losing speed) which I don't think was the case.

Physics 101. All objects fall at the same speed, and I quote the experiment of a hammer and a feather dropped on the moon that did impact at the same time. However, a storch is nowhere near as fast an aeroplane as the P47 nor lacks the accelerative potential, and since it's inherently a draggier design, it reaches it's terminal velocity sooner (assuming it's still in one piece).

 

I would suggest you be more discerning in your choice of sources when learning about aeroplanes, and get some instruction on the fundamentals of physics and aerodynamics which you clearly lack. Coming out with this sort of stuff doesn;'t impress me. I might not be an expert as such, but I have dealth with aircraft design before and have practical experience of aviation spanning some thirty years or more. Also, I remember the time when people read aviation publications that were written by serious authors, not sensationalist journalists chasing ideas on the internet.

[caesar novus]

I would suggest you be more discerning in your choice of sources when learning about aeroplanes, and get some instruction on the fundamentals of physics and aerodynamics which you clearly lack. Coming out with this sort of stuff doesn;'t impress me. I might not be an expert as such, but I have dealth with aircraft design before and have practical experience of aviation spanning some thirty years or more. Also, I remember the time when people read aviation publications that were written by serious authors, not sensationalist journalists chasing ideas on the internet.

Wow, you don't accept that actual p51 manual link as a good source. Pretty serious p47 book too in my link. These and the documentary reference aren't the source of my knowledge, but an attempt to point to shared or verifiable sources. So you didn't see or believe the Dogfights documentary - they often had the actual pilots giving accounts which I have read before, so can filter out the bombast. I used to check out 5 ww2 books a week from an air force library in the 1960's but I can't now reference page numbers for you out of Robert Johnsons "Thunderbolt", whozits "Stuka", or whoevers "Hurricane" for example.

 

Also I flew in that air base's aero club 42 years ago, even as a civilian kid too young to legally drive cars. It was crazy - There could be a military scramble at any moment, and I almost sheared off the landing gear on an arrester cable at the beginning of the runway (didn't know B-52's used them for overrun protection). They did make me solo offbase however, and I really learned more since then on gliders where engines can't pull you out of a jam. Now I remember the club had a ww2 trainer plane that I was too timid to sign up for time on, although I did have a ww2 pilot for ground school class. Most of the questions I missed on the pilots lic written test were about obsolete symbols only used on ww2 era training bases.

 

Anyway back to the fighter comparison. Here is a source of some juicy comparison teasers http://www.wwiiaircraftperformance.org/ . Oh, mercy... it probably has some flaws! But it is handy in a quick search vs the famous hardcover books we may have seen of UK, US, and German comparison tests or vs oral or newsgroup or ipod accounts. That reminds me... there are a lot of good ww2 aircraft lecture recordings on military museum sites, and I have listened to umpteen hours (maybe with fuzzy recall though).

 

54. The Thunderbolt has a greater radius of action at all engine settings and at all heights

 

Acceleration in straight and level flight

 

56. The Tempest has an advantage at all heights. Even at high altitude where the Thunderbolt is faster, the Tempest pulls away initially.

 

Zoom Climbs

 

58. At low altitudes and equal power the Thunderbolt has a slight advantage, but at full power and at high altitudes the Tempest has a definite advantage.

 

Dive

 

59. The Tempest II always out-dives the Thunderbolt, the advantage being more marked at full throttle.

 

Turning Circle

 

60. The Tempest II can always out-turn the Thunderbolt, the advantage being more marked to the left.

 

Manoeuvrability

 

65. The Tempest II is easy to fly and handles pleasantly in all manoeuvres. Its very high speed has been achieved with moderate wing loading and a high degree of manoeuvrability has therefore been retained. This aircraft, however, can never be equal in this respect to the current "Ju Jitsu" Japanese fighter which has sacrificed speed and armour for exaggerated manoeuvrability.

Edited August 24, 2011 by caesar novus

[caesar novus]

 

Anyway, how about I pull together MY BEST FIGHTER CANDIDATES in an ordered list with consistant template of issues. And they don't all have to be pretty-boys like the Spitfire. Spitfire beauty does reflect good design principles, but would you believe the above asymmetrical BV-141 is a successful too - it balances out the tendancy of propeller torque to turn left. I won't fact check everything on this list and will let eccentricity run rampant, so feel free to put up alternatives. Knock out two (first and last?) and you have 5.

 

1. Tempest2
   
   • KILL RATE: significant, but mainly it's own pilots when passed on unperfected to postwar India
     
   • WING EFFICIENCY: good
     
   • BODY DRAG: great for a radial engine, with a tight ducted fan cowling
     
   • POWER: lightweight robust radial
     
   • QUIRKS: not debugged or battle tested enough by war end, and an unfair preference by me
     

[*]Corsair

• KILL RATE: hurt it's own pilots until perfected kind of late in the war to find many targets
  
• WING EFFICIENCY: poor; draggy inverse gull wing; was optimized for sturdy stance on carrier.
  
• BODY DRAG: fairly tight cowl (no duct fan though) and clever cooling vents in wing leading edge.
  
• POWER: massive double radial with battle damage robustness
  
• QUIRKS: I think it had amazing potential not fully proven due to Pacific war wind down
  

[*]P-51

• KILL RATE: great
  
• WING EFFICIENCY: excellant laminar flow design with room for storage.
  
• BODY DRAG: pretty sleek, with oil cooler somewhat obtrusive
  
• POWER: great engine but with water cooled vulnerability
  
• QUIRKS: amazing range
  

[*]Fw-190

• KILL RATE: great
  
• WING EFFICIENCY: criticized as too short (high wing load) but fine to chase bombers
  
• BODY DRAG: efficient with innovative tight ducted fan cowl over radial
  
• POWER: great robust radial (sometimes replaced with inline)
  
• QUIRKS: propeller torque yawed it a lot to the left due to lightweight + radial
  

[*]P-47

• KILL RATE: good
  
• WING EFFICIENCY: good
  
• BODY DRAG: nasty; wide cowl for radial plus turbo which was bigger than bomber equivilents
  
• POWER: massive robust radial
  
• QUIRKS: heavy and sluggish until big paddle prop was introduced. 8 machine guns.
  

[*]Spitfire

• KILL RATE: good
  
• WING EFFICIENCY: excellant but expensive unroomy eliptical, later replaced by laminar flow
  
• BODY DRAG: excellant
  
• POWER: very good, but vulnerable water cooling
  
• QUIRKS: sleekness meant short range, and big engine upgrades hurt handling
  

[*]Bf-109, Hurricane, Hellcat, Zero

• KILL RATE: great
  
• QUIRKS: ageing technology, eg. light Zero could barely dive or turn right (major prop torque)
  

 

Weight means very little regarding dive performance since the aeroplane is accelerating faster than gravitional pull.

I doubt they go faster than gravitational pull. The below suggests to me that weight is always helping push you into a faster dive. But GRANTED the effect will be small and sometimes washed out by factors of a low drag design or powerful engine.

 

http://en.wikipedia.org/wiki/Drag_%28physics%29 sez "Note that the power needed to push an object through a fluid increases as the cube of the velocity." and "velocity asymptotically approaches a maximum value". With grav pull adding 22mph every second, you'd redline at 500mph in 23 seconds of freefall. If diving at an angle maintaining freefall you would tear off your wings sooner than that due to covering more diagonal distance per second. I believe this would happen in less than 15+K feet shown in the P51 dive diagrams. If furthermore a WW2 propeller can thrust almost it's own aircraft's weight in a climb, then it could accumulate 2G going down in a drag free world. That would halve the numbers above, leading to wings off on a dive of as little as 10 seconds.

 

I can see the phrase 'net thrust' is causing confusion.

Net thrust means the vent thrust exceeds the vent drag (sort of like a net profit), which I was denying. The Spitfire article on wiki says what I was affirming by reversing the phraseology "this used the cooling air to generate thrust, greatly reducing the NET DRAG produced by the radiators". That should clarify the meaning, regardless of factual disagreements (I don't like their word "greatly").

Edited August 25, 2011 by caesar novus

[Viggen]

pretty interesting and very detailed discussion, we all watch with awe the knowledge some have on this topic, please keep it that way and refrain from any personal attacks,

 

thanks and keep on going...

viggen