P-51 aerodynamics vs. spitfire

[HylaHyla]

Question to those possessing more knowledge on the subject. The P-51, I always thought, was relegated to bomber defense and was developed by British engineers and implemented by American manufacturers to be a fast, somewhat nimble fighter. I always believed the Spitfire to be more maneuverable and more of a dogfighter in tight situations. Having experienced the newly released P-51, I've found it to surpass the Spit in all roles. Is this reality or has the sim's recreation become something of a blown up version of reality?

 

[RIPSkyKingTasmanaut]

the spit definitely turns much tighter than the mustang in game, with better low speed handling

Edited October 5, 2019 by Tasmanaut

[CUJO_1970]

Where did you read it was developed by British engineers and implemented by American manufacturers?

 

A wise man once said "close this book and never open it again"

 

P-51 was never "relegated", but served in many different roles. 

[Venturi]

It was designed by North American Aviation. 

[357th_Dog]

The only part that came from the British was the Merlin in the 51B+..

 

the Mustang was designed for the British but not by them :)

[cardboard_killer]

The Spit was designed as an interceptor. The great fear of the 1930s was of strategic bombing by bombers so fast that contemporary fighters couldn't catch them. It turned out that that wasn't a problem, and escorts were needed. Escorts for strategic bombing need range to keep with the bombers, and in the case of the USAAF, high altitude performance. The P-51A had range, but poor high altitude performance until the Packard (merlin) was installed instead of the Allison.  The P-51A (Mustang II?) was used as a dive bomber with secondary A2A ability.

Edited October 5, 2019 by cardboard_killer

[LColony_Kong]

The P-51 cannot turn with the Spit in game. Not even close.

 

The P51 is significantly faster.

Edited October 5, 2019 by YIPPEE

[GP*]

Regarding speed, is the Mustang’s top speed appreciably faster than the 25 lb boost Spit? I don’t doubt that the Mustang can cruise a whole lot faster (and the Tempest is amazing in this regard at low to medium alt), but the 25 lb Spit is pretty quick at full grunt. 

Edited October 5, 2019 by Pre

[357th_Dog]

14 minutes ago, Pre said:

Regarding speed, is the Mustang’s top speed appreciably faster than the 25 lb boost Spit? I don’t doubt that the Mustang can cruise a whole lot faster (and the Tempest is amazing in this regard at low to medium alt), but the 25 lb Spit is pretty quick at full grunt. 

I think the 150 octane 51 will still get and keep about 20 mph on a +25 Spitfire 

[II/JG17_HerrMurf]

Anecdotally, the 51 is now the hardest AC in game for me to slow down in on landing approaches. That honor used to belong to the 109. She is one slick b*tch.

[-332FG-Hank_DG]

49 minutes ago, II/JG17_HerrMurf said:

Anecdotally, the 51 is now the hardest AC in game for me to slow down in on landing approaches. That honor used to belong to the 109. She is one slick b*tch.

I circled the field 4 times one sortie just to slow down enough to deploy flaps lol

[Gambit21]

The Mustang was the most aerodynamically "perfect" single engine aircraft of it's time. Perfect in quotes because of course it's not perfect, it just came the closest during the war.

Other aircraft might have been faster due to brute force, but nothing was as slippery in 1944-45. 

 

 

2 hours ago, cardboard_killer said:

 

. The P-51A (Mustang II?) was used as a dive bomber with secondary A2A ability.

 

It was called a "dive bomber" because that's where the funding was to design and build a new aircraft, the "pursuit" fund was dry at that juncture.

Thus the subterfuge. 

[LukeFF]

3 hours ago, HylaHyla said:

The P-51, I always thought, was relegated to bomber defense and was developed by British engineers and implemented by American manufacturers to be a fast, somewhat nimble fighter.

 

What?

[[DBS]Browning]

3 hours ago, Gambit21 said:

 nothing was as slippery in 1944-45. 

 

I suspect the P-63 might contest that title. 

[EAF19_Marsh]

11 minutes ago, [DBS]Browning said:

 

I suspect the P-63 might contest that title. 

 

Or that Goebbels character. He was pretty slimey

[Art-J]

5 hours ago, Gambit21 said:

It was called a "dive bomber" because that's where the funding was to design and build a new aircraft, the "pursuit" fund was dry at that juncture.

Thus the subterfuge. 

 

They came up, however, with A-36 and its divebrakes (I presume that's the one @cardboard_killer meant instead of P-51A), so it wasn't a complete subterfuge after all.

[cardboard_killer]

Yes; I thought the A-36 was the same plane as the P-51A, and it basically was without the dive brakes and nose guns. The Brits were high on it and it certainly beat the P-40s they were getting.

[Bremspropeller]

10 hours ago, cardboard_killer said:

The Spit was designed as an interceptor. The great fear of the 1930s was of strategic bombing by bombers so fast that contemporary fighters couldn't catch them.

 

Depends on what you want to label an "interceptor". I'd say that term is heavily influenced by american thinking, as both the P-47 and P-38 were designed as interceptors, hence the push for turbosuperchargers and good high altitude performance. In Europe, there were no such concerns: Nobody was afraid by another power coming across the ocean (Britannia still ruled those anyway) and also the air forces were heavily tied to ground-warfare. Even though the British were early in thinking about strategical bombing, in the mid 30s, there was no proven concept of that.

 

The Spitfire and Bf 109 reflected the classical mid-30s raceplane mindset:

Build the smallest possible airframe around a large-displacement V12 inline engine.

Unfortunately, that thinking yielded relatively poor tactical or even strategic growth-potential in both the 109 and Spitfire.

 

There were no stategical bombers in Europe that could label themselves as "fast", but tactical designs like the Ju 88 got VERY close to that state of mind.

Not to speak of the Bomber B project...

10 hours ago, cardboard_killer said:

The P-51A had range, but poor high altitude performance until the Packard (merlin) was installed instead of the Allison.  The P-51A (Mustang II?) was used as a dive bomber with secondary A2A ability.

 

The altitude performance of the Allison-powered 51s is about comparable to the Fw 190A - not great, not too bad either.

 

The RAF was quite pleased with their Allison Mustangs, which they used from around Dieppe with good success. The A-36 was much beloved by it's crews, but they had to be replaced as spares ran out and the airplane was somewhad of an orphan in the logistics of the USAAF, as only pretty few were built to keep NAA in the fighter business.

Luckily both the Brits and the Americans figured out that a Merlin was going to be a good idea in that airframe. The rest is history.

[56RAF_Roblex]

The P51 was indeed designed by the USA but it was so horrible that they did not want to use it and offered it to the RAF.   The British improved it and it then became a very good fighter.   As for which was better,  there is no doubt that the spit was no good for escorting bombers to Germany but I am not sure that the P51 was as good a dogfighter.   

[EAF19_Marsh]

1 minute ago, 56RAF_Roblex said:

The P51 was indeed designed by the USA but it was so horrible that they did not want to use it and offered it to the RAF.   The British improved it and it then became a very good fighter.   As for which was better,  there is no doubt that the spit was no good for escorting bombers to Germany but I am not sure that the P51 was as good a dogfighter.   

 

It was designed (voluntarily) by NA to a British request. It was not part of US planning. It was adopted by the USAAC slowly because the production and service use plans focussed on other (domestic and hence anticipated programmes).

 

The UK input was the engine and Malcom hood, otherwise it was a US aircraft.

 

The Spitfire could have been a longer-range escort fighter, but the RAF was not under any pressure for this kind of fighter so it was not pursued. The Mk. VIII had the potential for better endurance, but was never really used that way. RAF used Mustangs in any case, so the Spitfire range question never really arose (which seems odd to us, but at the time was lower on the priority list).

 

Equivalent Spitfires versions have a power-to-weight and wing-loading advantage over the P-51 which are classic ‘dogfight’ characteristics. In the real world, the Mustang combined good handling with high cruise and max speed, together with good dive, zoom climb and high-speed handling. That, plus appearing above and behind RLV formations, made it a great fighter, even if the Spitfire had some advantages in turn and sustained climb.

[Bremspropeller]

15 minutes ago, 56RAF_Roblex said:

The P51 was indeed designed by the USA but it was so horrible that they did not want to use it and offered it to the RAF.   The British improved it and it then became a very good fighter.   As for which was better,  there is no doubt that the spit was no good for escorting bombers to Germany but I am not sure that the P51 was as good a dogfighter.   

 

That is not accurate.

NAA was supposed to license-build P-40s for a RAF contract, to which they said "nah, we can build something better".

 

So they turned out the prototype of the P-51 within 117 days.

And indeed, they were correct - it was a much better airframe. It still lacked an engine to make most of it's much increased potential, though.

 

Both the US and the British had the idea that a Merlin was going to be a better engine to use the airplanes' capabilities independently.

Edited October 5, 2019 by Bremspropeller

[Voodoo_BlackDog]

This Spitfire out turns the mustang easily at all altitudes in this sim. Hours of testing with my Virtual fighter group has easily proved this. 

Most also historicaly correct.  

[cardboard_killer]

1 hour ago, Bremspropeller said:

The Spitfire and Bf 109 reflected the classical mid-30s raceplane mindset:

Build the smallest possible airframe around a large-displacement V12 inline engine.

 

. . . . to defeat the fast bomber scare of the 1930s.

[Bremspropeller]

14 minutes ago, cardboard_killer said:

. . . . to defeat the fast bomber scare of the 1930s.

 

Nope.

They just took the design-principles that had been used to design high-performing airplanes (e.g. on the german side the He 70 and the Bf 108) to the fighter level.

It was a natural evolution.

[GP*]

2 hours ago, 56RAF_Roblex said:

The P51 was indeed designed by the USA but it was so horrible that they did not want to use it and offered it to the RAF.   The British improved it and it then became a very good fighter.   As for which was better,  there is no doubt that the spit was no good for escorting bombers to Germany but I am not sure that the P51 was as good a dogfighter.   

Your post starts out laughably incorrect, but gets less incorrect over time. Good job I suppose? 
 

I only bring this up because there are multiple posts here that have the Mustang’s history all wrong. Where are people getting this stuff? 
 

The Brits paid for it when NAA pitched the idea and sold it, came up with the name Mustang (yup that was a pretty good one), and decided it was worthwhile to put a Merlin in it (the USAAF independently wanted the same thing). The rest was thanks to the fine folks over at NAA and their subcontractors. 

[EAF19_Marsh]

25 minutes ago, Bremspropeller said:

 

Nope.

They just took the design-principles that had been used to design high-performing airplanes (e.g. on the german side the He 70 and the Bf 108) to the fighter level.

It was a natural evolution.

 

The private venture was Supermarines and based on their work with previous racing aircraft. There was no He70 influence on the deign. But F16/36 was intended as a bomber interceptor and this was the general view that guiding fighter design principles. Fortunate coincidence.

[CUJO_1970]

1 hour ago, Valkyrie77 said:

This Spitfire out turns the mustang easily at all altitudes in this sim. Hours of testing with my Virtual fighter group has easily proved this. 

Most also historicaly correct.  

 

"Turning doesn’t win battles" - unknown Spitfire pilot.

 

Fighter design went away from turn doctrine and transitioned away to higher wing loads/higher speeds.

[II/JG17_HerrMurf]

Even if you are too lazy to pick up a book, Wikipedia has the answer. Where do some people get their information from? The Mustang history is extememly well documented and available to anyone who takes half a moment to look for it.

 

https://en.wikipedia.org/wiki/North_American_P-51_Mustang

Edited October 5, 2019 by II/JG17_HerrMurf

[=BES=Senor_Jefe]

11 hours ago, II/JG17_HerrMurf said:

Anecdotally, the 51 is now the hardest AC in game for me to slow down in on landing approaches. That honor used to belong to the 109. She is one slick b*tch.

Just cut throttle max out rpm and throw her into a level side slip (cross controls). Level side slips are a MAJOR no-no IRL GA aircraft, but this sim doesn’t punish uncoordinated slow flight enough, so use it!

[II/JG17_HerrMurf]

Even in a slip she's hard to slow down. I use a mid-field break turn to downwind and slip in the sim regularly to get on the deck quickly from speed.

[Bremspropeller]

Quote

They just took the design-principles that had been used to design high-performing airplanes (e.g. on the german side the He 70 and the Bf 108) to the fighter level.

It was a natural evolution.

 

27 minutes ago, EAF19_Marsh said:

The private venture was Supermarines and based on their work with previous racing aircraft. There was no He70 influence on the deign. But F16/36 was intended as a bomber interceptor and this was the general view that guiding fighter design principles. Fortunate coincidence.

 

Try again.

 

BTW:

The He 70 was a signle-engine, mono-wing, retractable gear airliner that held the speed record. It influenced ALL aircraft following.

I don't care about the elliptical wing.

 

Can you show exactly where the spec calls for the airplane to be a "bomber interceptor"?

It's pretty much a given that a fighter is supposed to be performing better than a contemporary bomber.

 

[56RAF_Roblex]

2 hours ago, Pre said:

Your post starts out laughably incorrect, but gets less incorrect over time. Good job I suppose? 
 

I only bring this up because there are multiple posts here that have the Mustang’s history all wrong. Where are people getting this stuff? 
 

The Brits paid for it when NAA pitched the idea and sold it, came up with the name Mustang (yup that was a pretty good one), and decided it was worthwhile to put a Merlin in it (the USAAF independently wanted the same thing). The rest was thanks to the fine folks over at NAA and their subcontractors. 

 

My post is absolutely correct but everyone is misreading and putting their own text between the lines.   The Brits asked for it, the Americans thought they would get something nice out of it for themselves while bypassing their budgetary controls but then decided it was a pile of crap and the Brits were welcome to it ?   It was indeed a pile of crap.   What it became on the other hand, and I fully agree it was joint effort once the Brits had shown it still had potential, was a very good all rounder even if it was not quite top of the charts in any one category.   

[Barfly67]

P51A subtypes were used by the Brits for low level recon until the end of the war, AFAIK.    It's performance was excellent below 10,000 ft, and competitive with late war types at sea level, reaching 350+ mph there.    That's as fast as a typical late 190A on boost, or late 109 on boost.   So I wouldn't say it was "crap"; it still had class leading aerodynamics by late war standards - an no one thinks the Tempest is not good, because it's engine output is optimized for medium to low altitude..

[Pict]

5 hours ago, EAF19_Marsh said:

The UK input was the engine and Malcom hood, otherwise it was a US aircraft.

 

British Air Ministry input was a tad greater than just that. They had a Bf109-E that had been captured intact in France by the french during the Battle of France and brought to the UK before France fell. All data from this 109 was made available to North American by the British Air Ministry during the design & development period of the P-51, as was other combat proven data from British designs like the Spitfire and so on.

 

Also don't forget that Hawker's designed the bubble canopy for the Typhoon, a design which was taken up by the US for the Thunderbolt & subsequent stuff like the P-51D, later Corsairs, Bearcats, YP-80's and so on...

 

or the "ace maker" gun-sight, which was also a British design copied by the US. So like it or lump it, the Mustang had a huge "foreign" input all the way from the start till it's later incarnations as we have in BOX  

 

6 minutes ago, Barfly said:

P51A subtypes were used by the Brits for low level recon until the end of the war, AFAIK.    It's performance was excellent below 10,000 ft, and competitive with late war types at sea level, reaching 350+ mph there.    That's as fast as a typical late 190A on boost, or late 109 on boost.   So I wouldn't say it was "crap"; it still had class leading aerodynamics by late war standards - an no one thinks the Tempest is not good, because it's engine output is optimized for medium to low altitude..

 

Yep agreed, a much under rated aircraft that was used to great effect in one of the biggest air battles of them all over Dieppe in 1942. I sincerely hope we get one at some point down the track.

 

I'd give you a like for that, but I'm over my limit for the day...I'll try and remember to do it later  

Edited October 5, 2019 by Pict
Spelling, tweaking etc.

[Gambit21]

10 hours ago, [DBS]Browning said:

 

I suspect the P-63 might contest that title. 

 

Interesting that you bring that up.

At the Reno Air Races some weeks back I spent quite a bit of time looking at and talking to the pilot of a P-63.

He said that below 10,000 feet I think it was, it's every bit as fast/good as the Mustang.

 

That said on this occasion he wasn't quite up there with the Mustangs during the race.

 

 

 

[LColony_Kong]

 

The P-63 is basically proof that the Allison engine was every bit as good as a DB605 or a Merlin. It just needed a supercharger. The 63 wound up using a D-coupled SC just like the 109.

Edited October 5, 2019 by YIPPEE

[GP*]

33 minutes ago, 56RAF_Roblex said:

 

My post is absolutely correct but everyone is misreading and putting their own text between the lines.   The Brits asked for it, the Americans thought they would get something nice out of it for themselves while bypassing their budgetary controls but then decided it was a pile of crap and the Brits were welcome to it ?   It was indeed a pile of crap.   What it became on the other hand, and I fully agree it was joint effort once the Brits had shown it still had potential, was a very good all rounder even if it was not quite top of the charts in any one category.   

Can you let me know the source for this information? My understanding is the following, and I would be genuinely surprised if the numerous sources I’ve read are wrong:

 

- Brits asked for additional P-40 production from NAA.

- NAA says “we can do one better” and designed the P-51.

- P-51 becomes a tremendous performer below 15,000 ft; above that I guess it could be called “crap.” 
 

 

[Barfly67]

To add to Pre's post above, NAA spent an undetermined but probably significant amount of time, doing basic design development on their new pursuit aircraft before the Brit's request.  So the 171 day prototyping doesn't really reflect the amount of effort put into the design.

[LColony_Kong]

5 hours ago, 56RAF_Roblex said:

As for which was better,  there is no doubt that the spit was no good for escorting bombers to Germany but I am not sure that the P51 was as good a dogfighter.   

The P-51 was slightly less agile than the 109 when slow and slightly more agile than a 190 when slow. It was MUCH faster than either when it first came out (much faster than a spitfire too), and remained faster even than late model 109s. At all altitudes.

 

Was it spitfire class turner? No. But neither was really anything else during ww2 in Europe. And turn performance was not what mattered. Top Speed and high altitude performance were what mattered. If turn performance was the most important thing the Japanese would have done alot better.

48 minutes ago, 56RAF_Roblex said:

was a very good all rounder even if it was not quite top of the charts in any one category. 

This is just nonsense. The P-51 had decent agility and climb.

 

And it had Top of the Charts Speed and Range.

[Pict]

11 minutes ago, YIPPEE said:

If turn performance was the most important thing the Japanese would have done alot better.

 

That would be why Grumman developed the Hellcat and then the Bearcat as the Wildcat couldn't out fight the Japs in a turn?

 

Seriously, the Hellcat could do everything better than a Zero and the Bearcat was better still but a tad to late for the fight. Then there's Nakajima with the Ki-84 that could do everything but range better than the Mustang

Edited October 5, 2019 by Pict
Spelling, tweaking etc.