f6f-5 vs 109

[drgondog]

Oh but Bill we do have the actual windtunnel established Cd0 figures for each a/c. What we lack is the HP to altitude.

Soren - "we" have yet to find and post wind tunnel data citing the Cd0 of the airframe. The Only DRAG comparison I have ever seen is in Lednicer's report that we touched on many times before and that was Fw 190D, Fw 190A, P-51 and Spit IX - IIRC that was the all in profile drag for one Reynolds number region.

The profile drag for each reynolds number (translated to speed range) for each aircraft will assist in finding the necessary force components as a function of velocity.

The Hp to altitude then enables the next step of comparitive altitude comparisons of thrust.

Neither of which is contained in the spreadsheets I have from Gene. I have since modified his spreadsheet to account for those variables but have not found the data to complete the model. BTW - gene does know his stuff.

Net - I haven't seen, and you have not presented any report of any wind tunnel test of any aircraft you lay claim to have parasite drag for. I know they must be available but I haven't found them on any of the public NASA sites with all the NACA airfoil stuff.

Absent that Soren, you really should not comment on the 'clear physics' of your thesis for tested or modelled comparisons.



Oh ok, fair enough, no problem. I'll do the calculations aswell if that is what you need. Lets use the Fw190 as our example where we know the Clmax.

Lift equation (FW190):

CL * A * .5 * r * V^2 = X Newtons

1.58 * 18.3 * .5 * 1.225 * 112^2 = 222152.045 N

Convert result in Newtons into kgf:

222152.045 Newtons = 22653.2 kgf

Divide result with a/c weight to get Max G:

22653.2 / 4270 = 5.3

Max G at 112 m/s (400 km/h):

5.3 G

So there we have the instantanious turn performance of the a/c. If we want the sustained turn performance we need take into consideration propulsive power drag.

This is correct for the first instant of the turn, before drag bleeds energy, angle of attack increases to sustain the altitude (level turn), and so on, and on and on.

Now tell me all of you who take the RAF tests as gospel, if you know your physics just slightly how can you at all take them seriously ? Why am I asking this ? Because the RAF somehow managed to turn a Fw190 JABO! with a P-51B, yet they couldn't manage that with a 109 ? That doesn't seem a tad odd to you ? Esp. considering that the Bf-109 always quite easily outturned the Fw190 in German comparative tests.

Soren, here is the 'thing'. The RAF test is just ONE piece of data for comparisons. If you would produce either USSR or German Tests with the same aircraft, those also could be reviewed and perhaps opinions changed?

Second - for every anecdote demonstrating the superb flying characteristics, superior turn performance, etc - there are at least "X" number more Encounter reports where the winner in a turning fight was a (Spit, Mustang) that turned inside and killed the 109. We KNOW pilot skill is a determinant. We KNOW that the winner writes Encounter Reports - so the use of anecdotal accounst as you continue to do is not productive.

As for pilots new to the 109 not being wary of the slats, well incase the 3 aces making that quite clear to you then we can also go further if you wish:

From the RAF tests with the Bf109G against the Tempest:
Turning Circle
47. The Tempest is slightly better, the Me.109G being embarrassed by its slots opening near the stall.

This pilot seems to have been oblivious to the purpose of the slats and how they functioned. First of all they don't begin to open 'near' the stall, and when they open they increase the Clmax critical AoA by 25%! That means you've got another 25% to go before you get near the stall.

So do you still believe that the RAF pushed the 109 to its' limits ?? Or do you finally see the pattern developing here ?

Assume the pilot DOES know the purpose of slats, and for some reason the ones on the tested ship are not operating to his expectations? Now introduce the counter evidence of the Rechlin comparitive tests. That is all anyone is asking when you dismiss either Brown or the RAE test pilots opinions of the 109 versus any other aircraft.

All anyone asks of you regarding 'physics' is that when you quote it you demonstrate that you know it.

Don't depend on Gene's models or tables. He knows his stuff but unless you can break down his models you don't know what his assumptions are. He may have changed his model but the one he sent to me is sea level, bench Hp at sea level - then calculate parasite drag from a calculated thrust for a table Hp at sea level, and a max speed for that setting at sea level.

Those ARE factors and data one can find in many sources (although many equally are contradictary)

It does not have an 'opinion' for any other altitude, it can not take into account a slat transistion, or control stiffness or trim condition or any other more minor but still significant modelling considerations to have a 'comprehensive physics' discussion.

Your opinions are ever so much more valued when you admit what you don't know or aren't sure of rather than dismiss opposing opinions as idiocy or get bent when someone respectfully asks you to produce evidence of your third party 'facts'.

 

[Kurfürst]

Some 20 RAF and 3 LW pilots tell us that Spit I turned better than 109E here, scroll down until subtitle Turning appears Spitfire Mk I versus Me 109 E

... how many of these claims of shooting down an enemy aircraft actually hold true? The RAF FC overclaimed something in the order of 2-3 to one during the Battle. Of course if you insist I can start spamming the page with LW claims of Spitfires and Hurricanes, I believe there are about 2000+ of these for just the BoB - many undoubtedly overclaiming or just damaging the aircraft. Can you explain how is this possible?

Oddly enough the site doesn't quote Erwin Leykauf and Herbert Kaiser though who claim the Emil could turn with the Spit, and oddly enough while it quotes snippets from Kurfürst - R.A.E. - Messerschmitt Me.109 Handling and Manoeuvrability Tests on the qualities of the 109E, though somehow the part that states that :

The gentle stall and good control under g (of the 109E) are of some importance, as they enable the pilot to get the most out of the aircraft in a circling dog-fight by flying very near the stall. As mentioned in section 5.1, the Me.109 pilot succeeded in keeping on the tail of the Spitfire in many cases, despite the latter aircraft's superior turning performance, because a number of the Spitfire pilots failed to tighten up the turn sufficiently. If the stick is pulled back too far on the Spitfire in a tight turn, the aircraft may stall rather violently, flick over on to its back, and spin. Knowledge of this undoubtedly deters the pilot from tightening his turn when being chased, particularly if he is not very experienced.

The RAE report also mentions that no comparison flights were made with the 109E using flaps to assist its manouvre, and that their calculation of turning circles are based on guesswork of the 109E's CL, based on stall speed measurements (which themselves vary quite a bit) of the Spitfire.

For what it worth, there are also German calculation about turning time and radii: http://www.kurfurst.org/Tactical_trials/109E_Kurvenwendigkeit/TB17-40_Kurwenwendigkeit_Me-typen.pdf

Quite clearly there were a lot more to the story than the Mike Williams site usually reveals.

On Spit IX vs 109G again scroll down until subtitle Pilot Accounts appears, there are at least hundred of them Spitfire Mk IX versus Me 109 G - Flight Testing

Oddly enough the same site quotes Pierre Clostermann's comments on in his late Tempest ride with a Sabre at +13 boost in April 1945, though somehow overlooked Pierre Clostermann's following comments while flying a Merlin 63 Spitfire Mk IXF (the +18 lbs boost version):

"I tried to fire on a '109' that I spotted in the chaos. Not possible, I couldn't get the correct angle. My plane juddered on the edge of a stall. It was comforting that the Spitfire turned better than the '109'! Certainly at high speed - but not at low speed."

Clostermann also has some unflattering comments about the lack of performance of late war Spitfires against the latest Luftwaffe fighters, as well as some comments regarding the Tempest vs 109.

Unsurprisingly, none of that are being quoted there.

And as always the man behind the stick was a very important factor in ac vs ac comparasion.

Agreed and supported by the great variaty shown in pilot accounts.

BTW Eric Brown flew Bf 109G-6/U2 with Rüststatz III and VI (droptank, 2cm gunpods) that landed in July 1944 in Britain. The aircraft appearantly lacked MW50 boost, and it belonged to a Wilde Sau night fighter unit. That was when flew the type for the first time, I believe I have read he flew it for a total of one hour.

Actually all of the RAF tests that are usually quoted are based on just a couple of aircraft:

Bf 109E-3, WNr 1304, that belly landed in France in 1939. Had some engine problems, appearantly MAP was falling with altitude.
Pingel's aircraft, a Bf 109F-2, that did a belly landing and was in a pretty awful shape esp. in the engine some test flight but no tac. comparison flights were made, as the aircraft suddenly dived and crashed after a while.
Bf 109G-2/trop, an aircraft that was left behind by the Germans in the desert in late 1942, as some of systems (hydraulics) were not working and there was some battle damage (splinter in prop). It was broken down in late 1943 and transferred to Britain, and was said to be in very poor shape, some parts were cannibalised from another 109 etc. Still exists, aka "Black Six".
Bf 109G-6/U2 w. R III and RVI, mentioned above. This was written off in a TO/L accident.


And most importantly of all, how did this discussion degenerated into the usual 109vsSpitfire turn exercise with the usual suspects?

 

[Kurfürst]

In the last part of the book he compares German fighters to American. He has flown the Me 109.

I am quite sure he didn't, as he is awfully ignorant of it (how the heck can he claims otherwise it had no automatic propeller pitch, that was appearing already in 1939 and was standard since about late 1940, and definitely so with the 109F...?)

Thing is Carson merely quotes parts of the RAE's report on the 109E, an early production example of the Emil captured by the French in 1939, and adds some malice to it. But geee, the Carson topic has been beaten to death so many times..

 

[Juha]

Hello Kurfürst
Quote:" Of course if you insist I can start spamming the page with LW claims of Spitfires and Hurricanes, I believe there are about 2000+ of these for just the BoB - many undoubtedly overclaiming or just damaging the aircraft. Can you explain how is this possible?"

Firstly, I put only a couple links, not spam anything
Secondly, if you have LW combat reports from BoB period, please put a couple on this site, on a new tread of course.
Thirdly, why Germans overclaimed, probably on same reasons that everybody else. If you mean, how they succeeded shot down many Spits and Hurris, Bf 109E was a very good fighter, Germans had many pilots with battle experience and their tactics were much better.

Quote:" And most importantly of all, how did this discussion degenerated into the usual 109vsSpitfire turn exercise with the usual suspects?"

You mean Soren's posts #24, 40 and 41?

Juha

 

[Waynos]

Going back a bit I know but why would British test pilots be afraid of slats? Its not as if they were unkown as they were, after all, a British invention and they were originally called 'Handley Page slots' (he British name for a slat is a slot) RAE pilots would be well familiarised with the device.

 

[Kurfürst]

Slats were first developed by Gustav Lachmann in 1918. A crash in August 1917, with a Rumper C aeroplane on account of stalling caused the idea to be put in a concrete form, and a small wooden model was built in 1917 in Cologne. In 1918, Lachmann presented a patent for leading edge slats in Germany. However, the German patent office at first rejected it as the office did not believe in the possibility of increasing lift by dividing the wing.

Independently of Lachmann, Frederick Handley-Page in Great Britain also developed the slotted wing as a way to postpone stall by reducing the turbulence over the wing at high angles of attack, and formally patented it in 1919; to avoid a patent challenge, the wealthy Handley Page offered Lachmann a job, which he accepted. That year a DeHaviland DH9 was fitted with slats and flown. Working with at the Handley-Page aircraft company, Lachmann was later responsible for a number of aircraft designs, including the Handley Page Hampden.

 

[FLYBOYJ]

Going back a bit I know but why would British test pilots be afraid of slats? Its not as if they were unkown as they were, after all, a British invention and they were originally called 'Handley Page slots' (he British name for a slat is a slot) RAE pilots would be well familiarised with the device.

My Point.

I could see during an initial flight but later on I could see the RAE wanting to evaluate the extent of their operation. Additionally if you do any type of full stalls (something at the "front end' of the flight test spectrum) you're going to have those slats deployed, additionally they should be deploying on landing. And I doubt RAE pilots never went on to fully stall captured 109s because of the LE slats opening.

 

[Waynos]

There ya go, like I said. The RAE pilots would have been flying planes with slots for years before they got a 109.

I stand partially corrected though K, I didn't know that was how Lachmann got his job at HP. So they both did it independantly but HP had the cash. Sorted.

 

[Soren]

Bill,

Bf-109 Cd0: 0.0023
Spitfire Cd0: 0.00229

We have the Clmax for each a/c so now we just need the HP vs Altitude.

And regarding the RAF tests, I've got several German tests directly contradiciting them. Take Hans Werner Lerche's comparison between the Bf-109G, La5FN Fw-190A8 in 1944:

The tactical conclusions and advice offered to German fighter pilots:
"The La 5FN is best suited to low altitude combat by virtue of its engine performance. Its top speed at ground level is slightly below that of the 190 and 109 (using MW 50). The 109 with MW 50 is superior over the whole height band in top speed and climb rate. Acceleration is comparable. Aileron effectiveness is better than the 109. Turning times at ground level are better than the 190 and worse than the 109.In rate of climb the 190 is poorer until 3000m. Because of its greater weight the 190 accelerates less well than the La5FN, but by the same token is superior in the dive. It is basically right to dive away like an American Thunderbolt when flying a 190, thereafter to pull away in a high speed shallow climb to reach a new attacking position, not to let the speed drop and to avoid prolonged turning dogfights."


Source: "Luftwaffe Test Pilot" by Hans Werner Lerche. He flew virtually all captured Allied aircraft and most German types, including experimental models.

Then there are the tests done by Heinrich Beauvais and several others, all concluding that the Bf-109 easily outturns the Fw-190.


Waynos,

The handley page slot was invented in England yes, but only a very few British a/c featured it, and those who did featured the fixed slot combination. Thus very few to none of the test pilots the RAF had had ever flown an a/c with slats, much less automatic LE slats.

 

[Graeme]

B-36 XB-35: swept wing, or not?

Odd site, but from it...

Yes Handley Page invented the automatic leading edge slat and traded
the patent with Messerschmitt for his method of constructing wings in
the 1920s. Handely Page did not invent the fixed leading edge slat or
slot (eg Me163) or the slat that is deployed by hydraulic forces. No
one bar the Germans put much emphasis on slats during WW2 and the
complicated mechanisms needed to make them work. Interest in leading
edge devices increased due to the need to provide high lift for the
swept wings reduced efficiency and to compensate for the pitch changes
of high lift trailing edge devices on low aspect ratio wings.

only a very few British a/c featured it

Interesting point. As far as British fighters incorporating leading edge slots/slats, there were only five (?)...

A 1926 version of the Bristol Fighter.
The Handley Page H.P.21.
The Boulton Paul P.31 Bitten.
The Westland Pterodactyl Mark V and the Whirlwind.

 

[drgondog]

Bill,

Bf-109 Cd0: 0.0023
Spitfire Cd0: 0.00229

Source and document please..

We have the Clmax for each a/c so now we just need the HP vs Altitude.

And regarding the RAF tests, I've got several German tests directly contradiciting them. Take Hans Werner Lerche's comparison between the Bf-109G, La5FN Fw-190A8 in 1944:

The tactical conclusions and advice offered to German fighter pilots:
"The La 5FN is best suited to low altitude combat by virtue of its engine performance. Its top speed at ground level is slightly below that of the 190 and 109 (using MW 50). The 109 with MW 50 is superior over the whole height band in top speed and climb rate. Acceleration is comparable. Aileron effectiveness is better than the 109. Turning times at ground level are better than the 190 and worse than the 109.In rate of climb the 190 is poorer until 3000m. Because of its greater weight the 190 accelerates less well than the La5FN, but by the same token is superior in the dive. It is basically right to dive away like an American Thunderbolt when flying a 190, thereafter to pull away in a high speed shallow climb to reach a new attacking position, not to let the speed drop and to avoid prolonged turning dogfights."

And this relates to 109 vs F6F, Spit or Mustang how?

Source: "Luftwaffe Test Pilot" by Hans Werner Lerche. He flew virtually all captured Allied aircraft and most German types, including experimental models.

Yes, the La 7 was one of the apendices at the back of the book

Then there are the tests done by Heinrich Beauvais and several others, all concluding that the Bf-109 easily outturns the Fw-190.

I believe you have said this many times, and that they are referenced from Rechlin 'tests', but you produce no document or tabulated results. This is/has been the subject of a lot of debate - you state but you don't produce the data.


Waynos,

The handley page slot was invented in England yes, but only a very few British a/c featured it, and those who did featured the fixed slot combination. Thus very few to none of the test pilots the RAF had had ever flown an a/c with slats, much less automatic LE slats.

And you know this how?

 

[Glider]

Soren
Re

Bill,
The handley page slot was invented in England yes, but only a very few British a/c featured it, and those who did featured the fixed slot combination. Thus very few to none of the test pilots the RAF had had ever flown an a/c with slats, much less automatic LE slats.

I might be missing something, but you seem to be working on the premise that the RAF test pilots had never flown the Lysander which at that time, was a pretty common aircraft in the RAF.

 

[Kurfürst]

I do not see whats the point of debate, regardless of the avarage British pilots familiarity or unfamiliarity with leading edge slats, the RAF test against the Tempest states quite clearly the pilot was emberassed by the opening of the slats, which certainly indicates (along with the relative lack of turn performance reported, ie. compared to FW 190 results) that he was not pushing the plane too hard in turns.

So whats the point in debating the details, the report is pretty clear about the a/c not being pushed to the edge. We can ponder on the why, but on what purpose...?

And as far as the F6 goes, I believe it wasn't tested against the captured 109G, so we can only guess about their relative merits, though I would not be surprised if the F6 was slightly better, wing loading was very slightly lower, though this could be a match considering the 109's high lift devices, good handling near the stall and good power to weight ratio.

What we know is that the G-2 required ca 20 secs to complete a 360 degree sustained turn at 1000 m, and a turning circle of 280 or so meters, presumably at low altitudes. This refers to 1.3ata performance, so at 1.42ata the turn time is likely to be a bit better. What are the comparable figures for the F6F?

 

[Juha]

Hello Kurfürst
Quote:" Oddly enough the site doesn't quote Erwin Leykauf and Herbert Kaiser though who claim the Emil could turn with the Spit."

Yes, it's a pity that the site doesn't quote Kaiser, because the complete quote continues after that what Soren quoted.
"…Our first victims were Mark Vs and it was not difficult opponent to Bf 109 F(-4) except in turning combat (Kurvenkampf) – so we simply avoid that kind of combat. When Allied made amphibious landings to North-Africa, Sicily and Italy, we met Mk IXs and they were entirely different opponents. We suffered in their claws…"
Source: Hannu Valtonen Messerschmitt Bf 109 ja Saksan... p. 228, his source was Christy, Joe (Ed.) WW II: Luftwaffe Combat Planes Aces. Vol 18 Modern Aviation Library, Book Number 218. p. 86.
Juha

 

[Kurfürst]

Can we see a scan of the page, Juha, and the full quote if you are so interested in full quotes?

BTW the quote is also interesting because it shows Kaiser's unit was not meeting Mark IXs until mid/late 1943... perhaps these were HF Mk IXs, I have seen on Mike's site these were introduced in March 1943? Although I am not sure sure which of the total of three examples of this Mark that were produced in the year 1943 he refers to.

 

[Juha]

Hello Kurfûrst
As I have wrote earlier, I haven't a scanner and anyway as the title shows, Valtonen's book is in Finnish. That's why I gave his source, there seems to be a lot of LW pilots opinions on Bf 109s in Christy's book, it might be an interesting book for you and for many of us. ISBN is 0-8306-9668-7. Valtonen gave the name in the notes as Christy but in bibliography as Cristy.

the quote ends "because they were 80kmh faster than Mk Vs and had 20mm cannon." That's all. Others are for ex Walter Wolfrum.

Juha

 

[KrazyKraut]

Soren
Re

I might be missing something, but you seem to be working on the premise that the RAF test pilots had never flown the Lysander which at that time, was a pretty common aircraft in the RAF.

Even if. I dare say it's rather unlikely they used the Lysander in turning combat so I doubt they would benefit from that experience.

 

[Juha]

Hello Kurfürst
in fact the landings in N-Africa happened in Nov 42 and soon after that Mk IXs arrived in NA.

KrazyKraut
in fact the only thing that might save Lysander in combat mission if it met enemy fighters was hard turning at zero feet, and Lysander pilots were trained for that, so your opinion might be wrong.

Juha

 

[KrazyKraut]

Aha okay. I don't know much about the plane and it just seemed unlikely that a liaison plane would be pushed to the limits like a fighter would.

 

[Kurfürst]

Hello Kurfûrst
As I have wrote earlier, I haven't a scanner and anyway as the title shows, Valtonen's book is in Finnish. That's why I gave his source, there seems to be a lot of LW pilots opinions on Bf 109s in Christy's book, it might be an interesting book for you and for many of us. ISBN is 0-8306-9668-7. Valtonen gave the name in the notes as Christy but in bibliography as Cristy.

the quote ends "because they were 80kmh faster than Mk Vs and had 20mm cannon." That's all. Others are for ex Walter Wolfrum.

Juha

Thank you for the info Juha, I will check it out, its probably very interesting. Pity that lately I order more books than I have time to read!