Was the corsair as good a fighter as the spitfire or the FW?

[Edgar Brooks]

His name wouldn't be Gaston by any chance?

Wash your mouth out with soap
It's often said that there are lies, damned lies, and statistics; it's very easy to take charts, figures, etc., and manipulate them to "prove" your theories, but nothing beats the practical experience of those who were there, and, during flight tests, the Spitfire consistently out-turned the P-51. As for not being comfortable with height, the service ceiling for the IX was 41,000', the XIV 21was 45,000', and the P.R.XIX 43,500'.
Edgar

 

[Shortround6]

To point to the difficulty of making charts and/or using simple formula's just look at the Spitfire with it's 3 wing tips. 232sq ft, 242 sq ft and 248.5 sq ft. The extended tips offered just 2.7% more wing area than the standard wing and as might be expected, pilots could detected little difference (except for slower roll) at low altitude, yet they did make a difference at high altitude. The aspect ratio of the wings was 4.58, 5.6 and 6.49 respectively. The smaller wings have less frontal area and less skin drag but the higher aspect ratio wing has less induced drag.

 

[post76]

Spitfires were about the best for high altitude flying. Low wing loading becomes progressively more important as altitude increases.

Wing loading is important at any altitude. At altitude, power output is important.
There is more to wing shape than just wing loading.

Have you read the manual for the Spit XIV?
âÉÂÌÉÏÔÅËÁ

Look under Handling.

It speaks of stability in a dive, and mentions the increased tail heaviness (nose up) encountered in the dive until compressibility is
reached then that changes to a nose down effect. That's got to be a bit difficult to manage at high speed, no? There's a whole paragraph on it in the manual.

It also forbids flying above 15,000ft under certain conditions, though the use of the rear fuselage tank has always been a limiting
factor of the Spit, older or later.

Dive limits in MPH are posted with altitude and they aren't noticeably greater than dive limits under the P-47D manual.
In fact the limits are higher in the P-47 by as much as 30mph depending on the altitude.
Now that could be for instrumentation reasons, right?
Another reason to use math.
I don't think its a question of whether the P-47 was the better diver, it was.

I simply said that both the P-51 and -47 held a higher sustained turn.

Actually the chart plotted G-load and speed at 22,000ft.
And now that i've had more time to think on it, it was a 4 G sustained turn.
Math actually is more revealing than comparing pilot opinions on two separate aircraft.
If you want to make an argument against the P-47 holding a higher sustained G turn than the Spitfire, you should say
"yeah, but what pilot in combat ever makes a flat turn!?!"
If the Spitfire noses down in a spiral dive it could hold a higher G turn than the P-47. The chart also demonstrated that.
The P-47 would be more effective at orbiting at altitude with out giving up altitude for speed.
I would expect the P-51 to be an improvement on what the P-47 because of better loading, but then output was neither as consistent or as powerful.

 

[fastmongrel]

By using maths and extensive research on google (3 minutes almost) I have proved once and for all that the Earth is flat, NASA never landed on the moon and that a Spitfire would be outurned by Dumbo below 15,000 feet.

 

[Readie]

By using maths and extensive research on google (3 minutes almost) I have proved once and for all that the Earth is flat, NASA never landed on the moon and that a Spitfire would outurned by Dumbo below 15,000 feet.

AND that the Supermarine Spitfire is so legendary that it is now perfect.

 

[jim]

AND that the Supermarine Spitfire is so legendary that it is now perfect.

Ok Mr Readie, Spit is (indeed !) the most elegant aircraft ever and possibly the most famous. If i was english, i would also be very proud of it!

 

[Glider]

It should also be noted that the P47N manual states that before going into a dive you should trim the flaps, close the cowl flaps, decrease the manifold pressure, do not retard the throttle quickly, just the sort of action you would do in a combat situation when there is plenty of time.

Should you get into compressability then the nose gets heavy, controls tighten up, sounds a bit like the Spit doesn't it. Then there is the blunt statement, intentional spinnng is forbidden. Also the types of aerobatics are limmited and the ominous phrase 'All other manoeuvers are prohibited. They teach you nothing and are extreamly dangerous'. It also makes a specfic point of emphasising that snap rolls can damage the structure.

In the Spitfire spinning is only banned when carrying external stores or fuel in the rear tank which is fair enough. Also the emphasise you put on the Spit getting tail heavy in a dive is misleading, you omitted to mention that the counteraction was to use the trim tab. Which is far less complicated than the list of does and don'ts associated with putting the P47 into any dive.

 

[Glider]

In fairness, I should add that I have found a copy of the P47D pilots notes and these are a lot better than the P47N. Spins are allowed but practice spins of more than half a turn were banned. In areobatics all normal aerobatics are permitted but outside loops or inverted flights are banned and snap roles banned over 150mph.

When diving aileron forces become high over 350 mph and the cowl flaps closed. The scary thing for me is that at limiting speed 12,000 ft should be allowed for, to ensure recovery which is a lot of altitude to use up. Also an indicated speed of 400mph should not be exceeded over 25,000 ft.

 

[post76]

It should also be noted that the P47N manual states that before going into a dive you should trim the flaps, close the cowl flaps, decrease the manifold pressure, do not retard the throttle quickly, just the sort of action you would do in a combat situation when there is plenty of time.

Good point, and perhaps being prepared is what the manual for an aircraft is all about.
In combat, would i suspect that a pilot has his cowl flaps open, his throttle wide open, and his trim out of neutral so that a sudden dive might require the adjustment of all those aspects of the aircraft to ensure the safest dive? Maybe only in a climb.
Look at other parts of the manual, if he's in combat, his cowl flaps would be closed, his flaps should be up, and he should only be prepared to trim and throttle, like any other plane.

Should you get into compressability then the nose gets heavy, controls tighten up, sounds a bit like the Spit doesn't it. Then there is the blunt statement, intentional spinnng is forbidden. Also the types of aerobatics are limmited and the ominous phrase 'All other manoeuvers are prohibited. They teach you nothing and are extreamly dangerous'. It also makes a specfic point of emphasising that snap rolls can damage the structure.

Sure, there are a list of limitations for every aircraft.
Most manuals, particularly training manuals always drill procedure with a healthy safety margin.
You seldom ever see them allowing spins, particularly if it is a training manual.
Normally, with spin limitations there is always an emphasis on speed.
If you were to tell me the Spit had a larger envelope for spinning, i would have to agree.
Intentionally spinning might only be done to practice recovery procedure while training.
Aside from spinning, the P-47 had good stall characteristics. "It doesn't have a tendency to spin."

In the Spitfire spinning is only banned when carrying external stores or fuel in the rear tank which is fair enough. Also the emphasise you put on the Spit getting tail heavy in a dive is misleading, you omitted to mention that the counteraction was to use the trim tab. Which is far less complicated than the list of does and don'ts associated with putting the P47 into any dive.

Actually, I referred to a paragraph out of the manual.
See my former post and look under Handling/Dive...
There is nothing misleading there.
Its the counteraction required of the trim tab that made it dangerous.
Going from countering "nose up" tendency to countering a "nose down" tendency in the event of compressibility.
It actually forbids the use of the trim in the event of compressibility and requires the pilot to use the control column alone.
Looking at the paragraph above that one, the pilot would also need to combat yaw, not uncommon when diving in most planes even the P-47.

The P-47: Most of what you refer to is the procedure for dive recovery in the event of compressibility which is a bit more extensive, otherwise normal procedure isn't that complicated but there are more limitations on the types of maneuvers the plane can perform going into a dive, such as a split S at full throttle.
It also states that at that time, it was a better understood phenomenon, something that earlier may have made compressibility more dangerous.

Anyways...
How does that make the later Spitfire less than ideal for high altitude flying?
Well, buy comparison if it needs to dive to hold a higher sustained turn than either P-47 or P-51, then its already losing altitude over those two birds.
If high speed dives are too dangerous to manage with trim in a Spit XIV, then it requires the pilot to manage all the force of the control column through
the dive which might also keep the pilot from diving as aggressively, perhaps at a shallower angle.
Fuel...The manual says 15,000ft with rear tank filled. My guess would be if it was intended to fly higher than that it would use the tank to climb, probably something
that was calculated in the field. Anyway, not much range, which also limits time in the air something already discussed earlier.

 

[Readie]

Lots of facts and figures but, our wonderful Spitfire outlived them all.
Cheers
John

 

[post76]

Lots of facts and figures but, our wonderful Spitfire outlived them all.
Cheers
John

Is that why they renamed it the Spiteful?

'cause they spitefully collected hanger dust, beautiful and fast though they were.

 

[Readie]

Is that why they renamed it the Spiteful?

'cause they spitefully collected hanger dust, beautiful and fast though they were.

Au contaire. No dust would dare settle on a Spitfire.
Joking apart for a moment. the IWM Spitfire could do with a good clean.
Its bordering on gross disrespect and I intend to write to the directors.

Cheers
John

 

[Hop]

Wing loading is important at any altitude.

It becomes more important with altitude. At 40,000 ft stall speed is about double what it is at sea level.

At 4 G it's also doubled.

Consider 2 planes, one stalls at 75, the other 100 mph.

At 40,000 ft, pulling a 4 G turn, the first plane stalls at 300 mph. The second at 400 mph. The small advantage in in sea level stall speed is much more significant at high altitude.

It speaks of stability in a dive, and mentions the increased tail heaviness (nose up) encountered in the dive until compressibility is
reached then that changes to a nose down effect. That's got to be a bit difficult to manage at high speed, no?

All WW2 fighters experienced trim changes with speed. A nose up attitude is much safer than nose down, which increases the speed of the dive and causes a positive feedback loop.

The RAF Mustang manual also notes that the Mustang is tail heavy (ie the nose rises), unless the fuselage tank is full, in which case it's nose heavy from the start.

It also forbids flying above 15,000ft under certain conditions, though the use of the rear fuselage tank has always been a limiting
factor of the Spit, older or later.

For the bubble canopied, fighter recce version only. Note also that is a post war restriction. The RAF actually removed the rear fuselage tanks from most Mustangs post war for the same safety reasons.

Dive limits in MPH are posted with altitude and they aren't noticeably greater than dive limits under the P-47D manual. In fact the limits are higher in the P-47 by as much as 30mph depending on the altitude.

From the the P-47 B, C, D and G manual Skycat posted http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/p-47-thunderbolt-manuals-5081-2.html

And for the Spitfire XIV:

That's a huge advantage for the Spitfire at high altitude.

The P-51N manual I have gives the dive limits as 360 IAS at 25,000 ft, 318 at 30,000 ft, which is better, but still not up to Spitfire standards.

Now that could be for instrumentation reasons, right?

It could be, but the test reports from both the British and Americans concluded the Spitfire had a much better limiting mach number, which is what is crucial in high altitude dives.

I don't think its a question of whether the P-47 was the better diver, it was.

Not at high altitude. The P-47 had too low a limiting mach number.

I simply said that both the P-51 and -47 held a higher sustained turn.

Actually the chart plotted G-load and speed at 22,000ft.
And now that i've had more time to think on it, it was a 4 G sustained turn.

No WW2 fighter could sustain 4 G at 20,000 ft. In fact 4G would be beyond them at sea level.

From memory, 3.5 G was about the limit, quite a bit lower for heavier/less powerful fighters. (Note I'm not including rocket powered aircraft, I haven't a clue about their turn performance)

Actually the chart plotted G-load and speed at 22,000ft.

Can we see this chart?

As others have said, it wasn't from Gaston was it? Gaston has a unique take on aircraft performance.

It actually forbids the use of the trim in the event of compressibility and requires the pilot to use the control column alone.

That's standard practice. The P-47 manual explains why:

"The elevator trim tab is not effective when the airplane is in compressibility. If you use it, the only result will be an extremely violent pull-out when you recover"

How does that make the later Spitfire less than ideal for high altitude flying?
Well, buy comparison if it needs to dive to hold a higher sustained turn than either P-47 or P-51, then its already losing altitude over those two birds.

This is something you keep stating but won't provide evidence for. Logically it doesn't stand up.

Look at it this way: the Mustang and Spitfire share the same engine, pretty much. You can find lower and higher altitude versions, and the Spitfire XIV has more power again at altitude.

The Mustang weighs more and has a smaller wing.

So the Spitfire has both a wing and power loading advantage. How is the Mustang supposed to turn better, exactly?

If high speed dives are too dangerous to manage with trim in a Spit XIV, then it requires the pilot to manage all the force of the control column through
the dive which might also keep the pilot from diving as aggressively, perhaps at a shallower angle.

No, the prohibition on trim during compressibility was pretty much universal. Trim tabs won't work when the plane is in compressibility. They will cause too rapid a pull out once they do begin to work.

Fuel...The manual says 15,000ft with rear tank filled.

For the fighter recce version with cut down fuselage.

 

[gjs238]

Is that why they renamed it the Spiteful?

'cause they spitefully collected hanger dust, beautiful and fast though they were.

Interesting that they needed to fix the Spitfire wing by replacing it with something that looks more like a Mustang wing.

 

[post76]

From the the P-47 B, C, D and G manual Skycat posted http://www.ww2aircraft.net/forum/other-mechanical-systems-tech/p-47-thunderbolt-manuals-5081-2.html

And for the Spitfire XIV:

That's a huge advantage for the Spitfire at high altitude.

fair enough...though early 47 manuals were loose numbers, but who's counting.
Test data is also revealing.

Not at high altitude. 'The P-47 test vs Spit test'.

Seen it, both test reveal similar figures for both planes.
Is it about mach, or is it about speed/acceleration?
If you look at TAS, they both reached the 605mph -610mph range.
The P-47 got there in 8000ft (22k ft) and in 12 seconds, albeit also in thicker air, while the Spit took nearly 15,000ft and 40 secondsfrom 40k ft.
Its a loose comparison but they were done around the same time period which might be the best to actually flying them side by side.
We can use other tests that put the mach number for the P-47 above .90...but who's counting.
I think the Spit actually cleared 0.95 in one test (677mph)....1948, diving all the way to deck from above 40,000ft.

No WW2 fighter could sustain 4 G at 20,000 ft. In fact 4G would be beyond them at sea level.

From memory, 3.5 G was about the limit, quite a bit lower for heavier/less powerful fighters. (Note I'm not including rocket powered aircraft, I haven't a clue about their turn performance)



Can we see this chart?

As others have said, it wasn't from Gaston was it? Gaston has a unique take on aircraft performance.

You mean a 3 minute google search doesn't reveal that chart?
Man....I got to do all the digging.
Wasn't Gaston, by name.
The chart was at 22,000ft between SpitIX and P-47D-22.
Different figures may have been revealed at higher altitudes and using later profiles.
At that height, the P-47 outperformed the Spit in sustained turns above XGs, and at XXXmph....
I haven't been able to find the chart, but its there somewhere in cyberspace.

Going higher would lower load limits for both aircraft, but at what height does the Spit putter out at?
P-47 late is good for max power to 35,000ft on some profiles.
The spit turning tighter would be no question, sustaining the turn with out also loosing altitude is another.

That's standard practice. The P-47 manual explains why:

The standard for the P-47 prior to dive is to set neutral trim settings.
There's no fussing with it.
The Spit manual(s) mention using trim because of a nose up tendency, but to avoid the use of trim above mach limits.


"The elevator trim tab is not effective when the airplane is in compressibility. If you use it, the only result will be an extremely violent pull-out when you recover"
Indeed, an almost identical description in both manuals but to say they read the same is cherry-picky-ish.
Read the whole section on dive and limitations for both manuals. I get a picture that the Spit nosed up more so in the dive leading up to compressibility than the P-47.

So the Spitfire has both a wing and power loading advantage. How is the Mustang supposed to turn better, exactly?

drag and power profile, particularly at altitude, if we're still talking about sustained turns.
There's also a saw tooth to the power chart because of the supercharger stages, which despite aircraft having "pretty much" the same engines
they can end up performing quite differently at different heights.

Google taught that.

No, the prohibition on trim during compressibility was pretty much universal.

Though you can probably take one sentence from every section of a handful of manuals and find common points, I wouldn't make the short cut in logic to say they are nearly the same in dive, either.

 

[Shortround6]

Interesting that they needed to fix the Spitfire wing by replacing it with something that looks more like a Mustang wing.

Gee, they "fixed" they Spitfire wing with something that looks more like a Mustang wing?

In Plane form? In airfoil? in structure? It is not surprising that they used a different wing on the Spiteful. It was only designed what, 8-9 years after the Spitfire? They only had about 25-30% more time after the Wright brothers flew to figure out a better wing for a plane that was 60% heavier, 130% more powerful and about 34% faster.

Good as the Spifire wing was for 1935-6 it was hardly state of the art in 1943. But then no wing designed in 1943 really made it into combat in WW II did it?

 

[Shortround6]

a few points.

I think the Spit actually cleared 0.95 in one test (677mph)....1948, diving all the way to deck from above 40,000ft.

Nobody dove these planes "all the way to deck' They Generally needed 10-12,000ft to pull out (recover). They also didn't go as fast down low, even in a dive, as they did higher up. Drag at "the deck" being roughly double what it is at 20,000ft.

Going higher would lower load limits for both aircraft, but at what height does the Spit putter out at?
P-47 late is good for max power to 35,000ft on some profiles.
The spit turning tighter would be no question, sustaining the turn with out also loosing altitude is another.

Some Spitfires "puttered out" at 43,000-45,000ft depending on engine. An indication of the planes ability to sustain a turn might be ( i could be wrong) reflected in it's climbing ability at a given altitude. A MK XIV in one test is shown climbing at 1800ft/min at 34,000ft. which is several hundred ft/min better than P-47M.


The P-47 could accelerate better in a dive, no question, and that is a very practical thing. A plane that accelerates quicker in a dive and use the increased separation to break contact before the slower accelerating ,but ultimately fast plane can catch up. In Reverse the slower accelerating plane CANNOT escape using a dive because it's opponent probably will not be out distanced until it has used up a considerable amount of ammunition.

However to say the Spitfires cannot dive is also wrong. Few fights were decided by dives of 20-30,000ft.

 

[davparlr]

A MK XIV in one test is shown climbing at 1800ft/min at 34,000ft. which is several hundred ft/min better than P-47M.

At equal fuel loads? I suspect the M may have been carrying 450-600 lbs more fuel than the Spit in the tests. Design fuel load for the P-47 was 205 gallons, the Spit XIV could only carry 109 gallons (or 130 US gallons if the number is UK gallons).

 

[Shortround6]

How do you want to figure fuel loads?

The Number of the Chart for the M was 13,275lbs. try sticking just 130gals US in a P-47M and see how far you get

Especially using a full power climb.

An older P-47 could use 91 gallons of fuel just warming up, takeing off and doing a combat climb to 25,000ft while weighing 12,500lbs. At 14,000lbs it 98 gallons to get to 25,000ft.

 

[Tante Ju]

The Spitfire, with it's lower induced drag, could hold higher sustained G than any comparable fighter.

Sorry but I think you hope too much for Spitfire. It was very good aircraft, but in my opinion airframe was somewhat obsolate by World War II. It represents peak technological advancement of 1935, but progress was fast, and Spitfire never developed to new results, only like garage tuning. No real modernisation program.

Drag has 2 elements. Induced drag is lower on Spitfire because low wingload. Parasite drag is very high for same reason compared to any other, probably greatest of any comparing WW2 fighter.
You make it look like as turn would be only about induced drag, but sorry, this is wrong. It is also about parasite drag.

Second. Drag is only one part of formula of turn. You are miss half of story, sorry... Sustained G hold capacity is dependent on which G load can fighter drag = fighter thrust.

You missed thrust complete. Thrust is very important. If you have more thrust, you can have more drag.

For this reason, your statement is not true. Both Soviet Jak 9 and Jak 3 fighters could hold higher sustained G than Spitfire. It is in tests. They achieved this with very small wing area and high wing loading. Yak 9 - 17 m2. Yak 3 - 14 m2. Latter is 15% smaller than Bf 109, only 60% wing area of Spitfire. Yet Jak 3 turns better and is much faster. Even Jak 9T with 37mm cannon could turn as good... Low parasite drag of airframe. So look at wingload, and it is not very meanful while not knowing thrust and parasite drag.

how does that make look like "big wing" designs? Not very good, dead end of technology, planes like Spitfire or Zero. They were good when engine power was small. That is why biplane has extreme big wing area, to generate lift, keep drag in turn low. But as engine power, smaller wing became superior. Big wing was declining dividient in long turn.