I edited it to suit reality, otherwise you may as well have put down 1ata or something equally 'not full power'.

These are just facts.


Manufacturer's quaranteed performance is not a test data and not relevent.

You were asked real test data for 500kmh and none has been posted.


Not specified but these are real tests of the real series planes.

Still, these match well with 109F speed 495kmh for 1.3ata, 500 kmh for 109E at same power or at 1.35ata is unlogical.


Yes in small degree, but much less speculation than assume series engine like you do.

Hm... in game test data is showing 475kmh which is actually slightly faster than swiss tests but acceptable.

Good work 1C, you are able to see behind speculations.

Edit: The point is that if you put doubt on various data on Spitfire at +12lbs, as you did, you should be just as critical in the case of the 109 data. Otherwise a reader gets impression of double standards.

No anykind of polemics, sarcasm, arrogance nor all those little annoyances intended. Leaving this discussion for next 5 days.

It's in the physics. If you look (very closely in well hidden places) at the turn calc spreadsheet I attached the other day, you can see that near each planes top speed, the 109 gains ~1.1 °/s turn rate for every m/s of speed given up, while the Spitfire gains about ~1.5 °/s turn rate for every m/s given up. This means in example, for a 9°/s turn rate the 109 loses ~29 km/h, while the Spitfire loses ~22 km/h and has thus narrowed the gap by ~7 km/h. It's a trend that continues until at low speeds the Spitfire becomes superior.

---

And can we all, now that we have a chance for few days of peace, just once try to get along with each other in a civilised way? No polemics, arrogance, sarcasm and all these little annoyances for say the next 5 days?

Are you aware of anything apart from a theory that agrees with this?

No you cannot, if a higher speed is such an advantage in a turn then turning when bounced would be an almost suicidal tactic. Yet it was that ability to turn that saved so many pilots. It was the one advantage that Spit V pilots had over the Fw190 and was emphasised at every plot briefing.

That would sum up the best tactic for Luftwaffe Pilots fight in the vertical and only do minor, brief turns to get a better shot. Try to turn it into a turning fight and the 109 loses.

Interesting that you keep talking about the 6 1/4 boost and not the 12 boost.

less than a 12 boost Spitfire

Spit every time.
Show any acual test that says otherwise. Show any 262 pilot who says that he would turn faster than any piston fighter.
No, their advantage was speed and the key was keeping your speed high and making it almost impossible to get a shot at you

I am still trying to work out how the German test authorities got it so wrong. I admit that I cannot find any reason and neither can anyone else, so maybe, just maybe they got it right and the 109 couldn't turn inside the Spitfire, after all thats what their official report says

The Falcon (one) manual told us some things that some seem to have forgotten, if they ever read them at all.

Two aircraft at the same speed pulling the same 'g' force, turn the same radius circle.

The same 'g' force at higher speed means an increased radius of turn, and a lower rate of turn.

At the same speed, a higher 'g' force causes a reduced turn radius and increased rate of turn.

This is why a fighter at .98 mach pulling 8 'g' can outturn a missile at 3.0 mach pulling 30 'g', the fighter's rate of turn is higher.

Which explains quite tidily why a Spitfire 1a never fell to a guided air-to-air missile throughout the entire Battle of Britain......

I'm a little out of my depth here but... I read somewhere that if speed and 'g' are equal then the turning circle is proportional to the wing loading and that is one of the reasons the spit out turns the 109.

If speed and 'g' are equal, then the circle must be the same size.

If a spit and a 109 are at the same speed, then the spit can pull more 'g' because the wing of the spit is bigger, and thus the loading (aircraft weight/wing area) is lower, and pulling more 'g' makes the circle smaller. This may fail as a rule when you get up to speeds where enough 'g' can be pulled to break the airframe, or to black out the pilot, but as I understand it these aircraft would have to be diving to get fast enough to break their airframes. It also doesn't apply below stalling speed.

<edit>

Wing loading isn't all the story, the Hurricane's wing was more heavily loaded than the Spitfire's, and the Hurricane turned better/pulled more 'g' at a given speed. The greater thickness of the Hurricane's wing I think had something to do with that.

Firstly if you think WWII fighter pilots were going to engage in modern energy theory concepts such as sustained optimum energy speed turn fights you are deluding yourselves. Concepts of Energy bleed Ps rates where not really in the the WWII fighter pilots thought process. Zoom and Boom or general turn fighting was. A spitfire pilots mindset was "I can outturn this 109'. The 109 pilots mindset was "I better be careful and not try to turn with this Spit"

The argument about the (debatable) slightly faster level speed of the 109 over the Spitfire means the 109 must have better sustained turn performance at these speeds is bogus imo. If you accept that for a given flight condition the 109 is faster so therefore has superior energy (Ps) than the Spit so therefore can transform this into turn performance advantage think about this. The superior energy (Ps) is only in 1G flight. As soon as you load the airframe up who has the lesser energy rate loss now ? .... i.e. energy bleed ? Ps at 1G and Ps at say 4G are totally different things ... JTD says it quite clearly and even provides some numbers :

"It's in the physics. If you look (very closely in well hidden places) at the turn calc spreadsheet I attached the other day, you can see that near each planes top speed, the 109 gains ~1.1 °/s turn rate for every m/s of speed given up, while the Spitfire gains about ~1.5 °/s turn rate for every m/s given up. This means in example, for a 9°/s turn rate the 109 loses ~29 km/h, while the Spitfire loses ~22 km/h and has thus narrowed the gap by ~7 km/h. It's a trend that continues until at low speeds the Spitfire becomes superior."

So once the G comes on the 109 is losing airspeed faster than the Spit..... and we know where the fight is going now don't we? 1G Ps and Ps under G are not the same thing.

Thats why JTD says (and is correct imo):

"It really sums up to that the 109's biggest advantage is in flying straight and level, it will remain competitive throughout the high & medium speed range, with the advantage always decreasing. All this, mind you, at sea level against a 6.25lb boosted Spitfire I, which is as good as it gets for the 109. "

Then we have this strange concept of the faster 109 being able to turn better than the Spit at say 400Kmh so therefore he can deny a Spit (at less than 400kmh) closing to a Guns shot ! Its an axiom of Defensive BFM that if you just keep turning a slower aircraft can simply arc inside your turn nose in lead and close to guns. Robbo puts it quite eloquently:

"But it is also possible to cut the corner of the 109 and shoot at it alright at lead curve, then ease up the turn and repeat. All depends on the trajectory, the planes will obviously turn on different circles etc. If you make a deal that the 109 won't climb or scissor, just turn, you will win. Because the Spitfire is much better TnB fighter than Emil. Emil is decent turner, too, very maneuvrable and agile, but as for the sustained turn competition in actual dogfight, Spitfire has got better qualities. "

Kurfurst
"Just explain how a plane with less or no excess thrust can pull a sustained turn better than a plane with more excess thrust, thank you"....

I'll have a go or comment at least :) We are talking about 2 aeroplanes one with marginally better 1G Ps at lets say 400kmh. As soon as the 109 starts to turn how much of this Ps superiority does he now have ? If his -Ve Ps under G is less than the Spit then fair enough but is it ? JTD's figure show the 109 -ve Ps under G to be worse than the Spit.

The RAE Fan charts (accepted that a couple of people here contest these) show this quite clearly.

I did not mean I agreed with Crumpps bizarre theory regarding superior sustained turn rate of a 109. :-P I was trying to explain to him the whole time that high speed turn rate of a 109 (or 190) was only usable in unsustained turns in actual dogfight - e.g. you would do 1/4 of turn or less and extend vertically. You would certainly not keep that turn sustained.

I was also saying the same thing to Kurfurst (IvanK and JtD both said it much better using proper terminology) - 400kph sustained turn is practically impossible to use because the 109 will bleed its speed rather fast - certainly faster than the Spitfire. Spitfire would be able to get the guns on the 109 if the 109 pilot maintained the sustained turn anyway.

I respectfully disagree - higher speed is a great advantage 'especially' when bouncing a slower target. All depends on the situation but in the example you name, the Fw 190 would really be able to outturn a Spitfire at very high speeds for long enough to get guns on him. That is obviously not sustained turn and therefore irrelevant.

Agreed completely, I guess we ment the same thing. There was also some confusion with what is and what is not sustained turn.

Crossed wires I think. It's entirely situational and depends where and when the Spitfire turns relative to the FW, and their speeds. The common tactic was, and one of Sailor Malan's 10 rules, to always turn into the enemy. This doesn't mean necessarily to do a head on, but to change his angles to one where he cannot get a shot off. A hard break, nose slightly down, from the high 6 is enough simply because in order for him to pull the snap turn (yes, a fast turn if you like) for the lead required, then he will overload and black out. The result is that the attacker usually misses behind or breaks off and gains height for another attack. So, the turn is no problem for the attacker, but only a fool would follow because as he unloads his turn becomes worse (as brilliantly described by other more intelligent posters than myself) and the advantage switches.

What I find confusing though is what I've often read, that a 109 would dive from above and the spitfire, lower and slower, would make a left hand spiral break yet catch the 109 and shoot him down. I guess it's just descriptions, only I can't picture that exactly. Maybe the speeds are similar in the DF the pilot talks about. :confused:

Can people stop referring to the Spitfire as slower when it isn't. Thanks.

These are the precautions given to Spitfire pilots facing the Fw 190:

http://i91.photobucket.com/albums/k3...0-page-002.jpg
http://i91.photobucket.com/albums/k3...0-page-004.jpg
http://i91.photobucket.com/albums/k3...0-page-005.jpg

Essentially the advice was to cruise as fast as possible, especially in the danger zones where Fw 190s were expected, partly because the Spitfire was slower to accelerate than the 190.

As for claims that the Bf 109E generated less drag than the Spitfire I - there has been no objective data presented to prove this, but here are the figure for the Spitfire I:

http://i91.photobucket.com/albums/k3...g-page-002.jpg

Nope, this is just your opinion and has nothing to do with any test report's contents.

Unfortunately it is test data and it is relevant. Unless you want to dream up specifications.

Oh they were, you just happen to ignore them.

In unknown conditions..

Oh but an 500+ kph Spitfire I as fast as the 109F *IS* logical, riiiiight?

Thank you for admitting that your remark about supposed two speed superchargers was just speculation.

As for my my "assumptions" about the engine, here is what the test report has to say about it:

Motor: DB 601 A, serial number 140.

Quite clear cut is it not?

They did see through speculations, that's why the final patch is going to fix the SL speed of the 109E to its historical 500 kph-ish value.

I see. Your position is, if I got it right, that a completely unreferenced graph, without any details showing 6 1/4 boost performance, on which somebody draw up ex post facto his wishful estimates on +12 and even a fantasy +16 boosted level speed performance with a pencil, for the Mark I. Spitfire has the same credibility as the most detailed test on the 109E, which contains engine bench test data, airframe conditions data, calibration curves, and has been appropriately corrected for German Standard Day conditions.

I respectfully disagree with your assessment.

Indeed they might get this idea. Statements like "Manufacturer's quaranteed performance is not relevent" may lead to such conclusions.

(Glider remains silent on the issue)

In fact we all do, except for you. The discussion is about trying to explain to you the fact that the 109E has a better sustained turn than the Spitfire using 6 1/4 boost at and above 400 km/h near SL.

(Glider remains silent on the issue)

... and how much is that David?

And why is that, David? How can a Spitfire sustain a turn without any excess thrust to start with? Does it have anti gravity drives perhaps? Can it just defy the rules of physics?

I am sorry David, but I believe that you did not fully grasp some of the basic elements of the this discussion, such as the difference between sustained and unsustained turns, the effects of parasitic and induced drag depending on airspeed and the importance of thurst and excess thrust. So let me put it down for you in the most simply terms:

Unfurtunately, the Spitfire cannot sustain a turn at 400 mph at all. Depending on altitude, it has either ZERO or NEGATIVE "excess" thrust already at 1 g.

We have been over this already anway, see http://forum.1cpublishing.eu/showpos...&postcount=194

http://forum.1cpublishing.eu/attachm...2&d=1347990667

In short, the 262 (blue line) starts to run circles around the Spitfire IX (red line) above 460 km/h. At 640 kph, the Spitfire is outright hapless...


Nope, they got it exactly right. They say:

In summary, it can be said that all three enemy planes types are inferior to the German planes regarding the flying qualities. Especially the Spitfire has bad rudder and elevator stability on the target approach. In addition the wing-mounted weapons have the known shooting-technique disadvantages.

It seems to me that the Germans regarded the flying qualities of the Spitfire overall inferior to their fighters.

Kurfurst you are full of charts which are calculated by yourself and crumpp, however you never talk about the real tests undertaken by the real pilots and real test establishments.
I know what I know and I acknowledge what I don't.

You talk about the 6 1/4 boost and I talk about the 12 boost. Why, because the RAF fighters in the BOB used 12 boost. You talk about the 6 1/4 boost because that gives the 109 a better chance, not what they faced in combat, a big difference.

The one part of the report that you quote
In summary, it can be said that all three enemy planes types are inferior to the German planes regarding the flying qualities. Especially the Spitfire has bad rudder and elevator stability on the target approach. In addition the wing-mounted weapons have the known shooting-technique disadvantages
You make a big deal on this but forget to mention that the Spit in question didn't have the CSP only the two pitch prop which they rightly make a number of comments about. No one is trying to pretend that the Spit was the greatest gun platform which is part of the equation and they had wing mounted guns, not exactly new.

However you don't quote the bit about turning which is what the conversation is about, interesting. So just to be clear, do you also agree they had it right when they said
Before turning fights with the Bf 109 E type, it must be noted in every case, that
all three foreign planes have significantly smaller turning circles and turning times.
An attack on the opponent as well as disengagement can only be accomplished on the basis of existing superiority in performance.

In which case what are you disagreeing about, or are you only disagreeing with the bits you don't like?

I agree with everything that the report says, will you make the same statement?

As for the 262 I notice another nice chart but nothing re tests or pilot experience so it remains a theory, no more no less.

The chart Kurfürst posted is not a theory, it's a calculation. Physics and maths are just as relevant as tests and pilot experience. There are methods that are standard and accepted. If you use them properly, they can be more accurate than tests and pilot experience and are imho at least as valid.

Hi kufurst, any chance you can link me to the records of the 109e maintaining 500kph in level flight at sealevel. Sorry if you've posted this before. Ta.

Edit; sorry I see you never stated sea level. My mistake. Unless SL means sea level, and not STRAIGHT Line?

No actually. I have mentioned this twice and you just ignored it.

I have some good news for you though. 1946 HSFX patch 15 just fixed the Hurricane I and Spitfire I FM's to the speeds we talk about here. They are bang on the RAE tests using 12lbs. Fantastic news don't you think? ! I am interested in the link you are referring to for the 109 too because I think the 109E in HSFX may be too slow, but I want a proper flight test, not some calculation which Willie cooked his books in order to win a big fat order from his pal Hitler.

In 1940 I presume, not the enitre war? ;) and when they say "inferior" you mean slightly worse by a small margin? Translation error? German translation can be very direct.

This is the sort of thing that raises my doubts. I am confident that the Grippen had many thosands of calculations undertaken by some of the finest minds in aviation. Using the latest computers, many hours in a simulator and then this happened. I should add that this was being flown by a test pilot.

http://www.youtube.com/watch?v=k6yVU_yYtEc

Show me any report of any 262 pilots who would go into a turning dogfight against a Mustang, Spit, La 7, whatever take your pick. The theoretical world is one thing, hard combat another.
Look at it another way, Why did the Mig 17 do so well against the F4, F105 and so on. Find any US pilot who would go into a turning combat in any of the above against an old slow Mig 17.

I love the way Kurfurst seems to think the 262 would even be in with a shot at a turning fight, at those speeds it's going to fly circles so big it's circumnavigating the globe :rolleyes:

It's not about turning fights, it's about the ability of a plane to sustain a turn at a given speed. That's what the chart shows. It's something else what you make of it - both here at the forum discussing it, and in the air piloting these planes.

Like with that Gripen, most accidents happen due to pilot error, not erroneous design calculations. It's rather an argument against the reliability of pilot accounts, than an argument against reliability of maths and physics - so I'm not quite sure why you posted the video.

Here it is. It is as proper as a flight test can get. In fact, its the most detailed performance test I have seen so far. http://kurfurst.org/Performance_test...w_109V15a.html

Of particular interest, translated from the paper.

Condition of the airframe :

The surface was painted after the serial production standard. The engine cowling was still rough, exhaust manifolds (DB-type, made at BFW) were lacking top cover. 2 Cowl- and wing-MGs were installed. Antenna wire. Undercarriage retracted, tailwheel out. For air intake, see the reports drawings.

Radiator cooler flaps were 1/4 open. Coolant temperature observed as constant 90 degrees Celsius.
Oil cooler flaps were closed. Oil temperature observed as 62/82 degrees Celsius.'

Speed was measured on the four-way flight track in Haunstetten. Altiude trials were performed near Augsburg airfield.

Measured speed for 0 m was 493 kph at 1,33ata. The engine was measured on test bench, and was found to develop 45 PS less than the guaranteed nominal output at 1,35 ata, so the flight results were corrected (see Blatt 5 for calculations) to the nominal engine ratings and German Standard day : 498 km/h at 0 m (CINA) at 1.35ata..

It is, actually. Given that the complete lack of + 12 lbs tests, the likely farce but not unreasonable RAE "test" paper is the only source the FM modellers can use.

You see the problem with this kind of thought is that after Willie would have won that big fat order, he would also have to deliver some 4000 aircraft and each will be tested by the German Air Ministry for specs. If they are not capable being withing plus/minus five percent of the figures Willie promised, Willie won't get a single Pfenning, which doesn't sound like a very good deal.

By the time it was allowed to be a fighter those pilots had little intention of being fighters what with the sheer number of escorts to deal with. No, get fast and whip through the formations with those mighty cannon.

Regarding level speed performance of the 109, a question raised by I think MiG-3U puzzled me, maybe you have a good explanation, I'm at a loss for now: How come the 109E is faster than the 109F at less power, if you accept the 498 km/h for the 109E at 990ish hp from the V15 test and the 495 km/h for the 109F at 1065ish hp from the 109F Kennblatt?

Oh, have I misunderstood something? I just figured since the thread went OT within 7 pages or so and it turned into an argument about which aircraft had the turning advantage it 'was' about turning fights, if I'm not mistaken that is exactly what triggered the whole change of topic was a turning circle diagram and the usual suspects denying that the Spit would win in a turning fight.

Hmmm, this isn't an original document, it's some html from your website. All of the RAE stuff and other docs are originals (except the 12lbs which is measured in test then calculated/translated/projected onto the graph)

Don't be silly Kurfurst. Willy is an old pal of Goering and a few keys of Colombian marching powder and some bonus wraps he'd have been on the hotline to Herr Hitler. We've all seen how Oscar Schindler did it.

I could be wrong but I think he was being sarcastic in order to question Kurfursts 498kmph figures. Glider confused me too since he dissected MiG3U's post as if it were in support of Kurfurst, when it wasn't.

Doesn't the V in a designation mean a prototype/test a/c?

Bf 109 V15a

Just a stab, Kurfürst is probably the man for this question but looking up the weight of the 109e and 109f and it appears the later is heavier when loaded which might help account for the lack of speed increase over the emil?

Its difficult to say how much it is on the 109F Kennblatt because the Kennblatt's figures are with the original ratings of the 601N at 495/515 (1.42/1.3, which were reduced to 1.25). In short the 495ish figure is for 1.3ata.

My best guess is that there was a major difference between the Emil and Friedrich propellers (also according to the propeller effiency curves I have seen), the latter was of smaller diameter and almost certainly meant for high altitudes, and probably less efficient in denser air, hence the relative stagnation of speed near SL. The Friedrich would be probably faster with a different prop.

But all of this is not so extraordinary or a surprise since the same can be noted when it comes to the Mark I / Mark V / Mark IX Spitfires's evolution. Hell the Mark I. at +12 is supposedly faster at SL than the Mark IX at +15 boost, how come..?

True..

Agreed.. Just as relevant.. If used properly

As you (and others) know the old saying..

Garbage in Garbage out!

With regards to flight simulation..

You can think of the 6DOF flight simulation model as a black box.. With an input (plane parameters and current state) and an output (results)

The math in the black box can be good to go.. no errors.. But if you input bad values (plane parameters and current state) you will get bogus outputs (results)

With that in said..

I don't know if the 'results' of the Me262 or Spit used in the IL2Comp graph Kurfust posted have ever been validated.. As in have they ever been compared to any real world data, or checked by someone else to ensure the 'inputs' are correct.

In short, in this case the IL2Comp values are suspect until validated.. Sadly I don't know of any real world turn time data of the Me262 that can be used to validate the IL2Comp, which leaves only for someone to doulbe check the input values and 6DOF math.

You want the original document, Osprey?

Except it just didn't work that way. BAL (the Luftwaffe's QC group) was rejecting Me 262 if they did not do at least 830 kph.. They had a bit of reason and allowed planes even with 825, but no less was accepted.

Again. We are talking 262s. In 1945.

Thanks Kurfurst, I’d not seen the V15 trials information before, the test-report is quite nice. Although I’d much rather have all of the pgaes in their originals, not just a few, and not have to rely on transcribed text into your html page.

The above aside, can you help me with a couple of questions:
1) What can we take from the apparent inability of any subsequent tests of the E1s or E3s (that I can find at least) to get anywhere near the “sea-level” (see question 4 below) speed of 493kmh or 498kmh? How do we explain that the prototype was able to record speeds that no subsequent 109 testing seems to have been able to achieve? I see testing data of 109E3 Nr1972, and 109E1s Nr1774 and Nr1791 (all of which are German tests, not British tests), none of which achieve above 485kmh at their lowest altitude of “0” (average is around 470)

2) Can you provide Blatt 3 of the testing documentation, the full-pressure altitude (Volldruckhohen) results – which I cannot find on your page?

3) Your tabulated summary of Blatt 5 indicates that the achieved speed (with the supposedly suboptimal engine pressures) was 493kpm at 0 altitude relative to the ground. Why does Blatt 6 indicate however that only 485 was obtained? is that because Blatt6 projects the speed down to sea level, whereas the tests were carried out at 0 altitude above ground, at a location (Augsburg?) already elevated (~440m) above MSL? If so, according to the test graph, do we get a sea-level speed of 485(490), not 493(498) for the V15?

4) the tests often make corrections for air pressure of a standard (Augsburg?) day "normaltag". Do we know what that pressure was?

Some are drawing wrong conclusions from the chart, but that doesn't change the chart. Kurfürst said the 262 can sustain a better turn time than the Spitfire at 400 mph, which is true. This will not win it a sustained turn fight though, as the Spitfire doesn't need to match the 262's speed. It can't do it in straight and level flight, so why bother in turns. Like I said, there's the chart and there's what you make of it.OK, I can see that at altitude the F is at least faster than the E, even if still at more power. Do you have the propeller efficiencies somewhere so I could take a look at them? Regarding the Spits, the IX was quite a bit more dirty than the I, just like a G-6 was more dirty than an F. So I would expect it to need more power for the same speed. But the E-F issue is different.Yes, 109E prototype.Weight certainly is a factor, but for top speed of high speed fighter aircraft the effect is rather small. It matters much more for climb and turn.

Lack of documentation for this claim noted. Still waiting for data proving the 109E had less drag than the Spitfire I.

Also noted

Yes that would be something to see!

In fact, I am pretty sure that most of the airplane shot down by the 262 were Spitfire and Mustang. There is some video on the net showing 262 involve in turning fight. Some are really dramatics. You shld take a look into that instead of preaching endlessly that nothing came close to the Spit in term of turn fight.

Turning is all about changing direction. If your plane is stuck at the limit of his performances there is no chance for it to turn corners. That's why fighters pilot enjoyed speed as the most valuable perfs... until reliable short range missile came ;)

The Mig17 Vs F4 is quite a good example. Pass the Mach 0.9 and then the F4 had the advantage. Especially in high G pull up and vertical manoevre. Exvatly what was teach at TopGun (see the the story of R. Cuningham). An F105 could turn with a 17... Above the mach ;)

Keep in Mind that BFM is all about E not turning circle. It's pretty easy to understand that with the late gen fighters. But so much could be said.

What is more likely to go wrong, A prototype on its sixth flight or a test pilot of many years experience. The problem was traced to issues with the avionics and delayed responses to control input, not pilot error.
These had been calculated and tested in simlators but it was only when they flew that the problem was idnetified.
So the calculations and theory was flawed resulting in a serious accident the pilot was lucky to get away with. People who rely on theory are banking the farm on a theory and thats why I posted the video.

I notice that no one has come up with any examples of an F4, F105 or 262 taking on a slower aircraft in a turning fight. The F4 and F105 people say that they had the advantage in a turning fight at over 0.9. If this is the case then why didn't the US pilots use that advantage?
Its a simple question, in reality they didn't, they used their speed to go vertical or gain a tactical advantage.

This is the core of the difference. In Vietman I can find examples of US pilots going vertical or using speed to gain a tactical advantage. No one has (so far) show that US pilot wanted to go into a turning fight.
I believe from what I have read that the 262 pilots did exactly the same thing.

PS the main target for the 262 were the bombers, not fighters

As far as the game goes, do you want it to reflect what could happen, or did happen.

Going back to the subject. I do get a little frustrated when people pick and choose which part of the offical test reports they agree with.

Can I ask you if you agree with what the German test establishment said about the 109 and Spitfire? I do in its entirety good and bad from all points.

Tht's what I am saying here, Glider. Changing direction is not about drawing circles like a compass with your plane but to point your nose faster in the intended direction that your opponent.

Again, if your plane fly at the limit of his envelope you have no chance in term of manoeuvrability. A faster plane will fight at a higher speed were he is more efficient in term of E. This what hve ruined Il2 with a Spit that never depleted his E (and again in CoD) turning basic BFM useless (YoYo for example).

Are you suggesting that the CLoD spit does not loose energy in the turn?

Then why is prototype data being used and not data from a production Bf109E?

Based on past experience with Kurfürst.. My guess would be the prototype data has better results than the production data.. That is to say Kurfürst tends to go with the best of the best data for 109s and the worst of the worst data for anything allied.. Also known as cherry picking!

Awww, why so serious? Anyway, Check out http://www.wwiiaircraftperformance.o...09/me109e.html

OK, so they did employ maths and physics improperly. I'm fairly certain that they came up with proper calculations after the accident and managed to simulate the problem. Just like we can calculate turn performance nowadays, the calculation is sound and all you can do wrong is input data.You're wrong, Spits always flew to the same physics that applied to all other planes. The reason it could sustain a 17s turn is because it's one of the aircraft's design features. Just like high speed was a design feature of the Fw 190, which had no problem whatsoever to outrun Spitfires. Take a ton off a 190, give 200 extra hp at altitude and add 20% drag, and you got yourself a Spitfire.

The facts:
1. Prototype aircraft V15a, tested well before production started
2. Tested speed 493kmh at altitude of 440m, gives 485kmh at 0m
3. The supercharger has two fixed speeds:
- boden- and hohenlader are claimed and the optimal change altitude is determined
- manifold pressure drops above the FTH of the bodenlader, until hohenlader is set on
- the speed test confirms that the supercharger has two fixed speeds
- according to Flugmotoren und Strahltriebwerke by Kyrill von Gersdorff, Kurt Grasmann, Helmut Schubert the first order of the DB601 was the pre-series of 150 motors, A-0 ie Baureihe A (carburator engine with fixed speed supercharger), so based on engine number of 140, the V15a had one of these instead a A-1. The hydralic clutch came later with the Baureihe B along with fuel injection.

It's not a test, just a piece of paper, no test data nor kenblats of production planes support 500km/h at sealevel. Everything else is around 460-470km/h including swiss planes with the 601Aa.

Calculating the speed of the the Spitfire I at +12lbs the same way as done in the V15A report:

Density at sealevel: 1.225 kg/cubic meter
Power at sealevel at +6.25lbs: 880hp
Power at sealevel at +12lbs: 1180hp
Speed at sealevel at +6.25lbs: 280mph

r = ((1180/880)*(1.225/1.225))^(1/3) = 1.103

V0 = 280mph * 1.103 = 309mph = 497kmh

However, that is a crude, unaccurate and partially wrong way to calculate it.

The only speculative but logically correct part in my post is the size of the oil cooler, and it was there only because you asked it. The rest are facts.

Thanks for correcting the power of the 601N.

We do have several datapoints for production 109E giving 460-470kmh at 1.3ata and 990hp.
Calculating again the speeds of the 109E same crude way using 470kmh as base line:
601Aa 1045hp = 479kmh
601N 1060hp = 481kmh

Then we have the 109F doing 495kmh ie about 15kmh faster than the 109E at same power, that difference is roughly same as found at FTH. These values match very well while 500kmh is clearly an outlier and not supported by any test or kenbalt of the production planes.

Would you mind, TomcatVIP, not slandering me by implying that I am some sort of Spitfire fanboy. I don't appreciate it because it's just not true. You constantly insult people with your replies, it's all in the tone you apply, and then you often go on to make ludicrous statements afterward (such as the one about no energy loss for the Spitfire in COD).

If you reply to me again in this manner then I'll report it. The mods here are hot on infractions.

I am completely with you here (although I am a huge Bf 109 fan), the Mtt 500kph +-5% guarantee debate has been here before and I was saying pretty much what you're saying now.

Fact: report says aircraft is identical to production E-1.

Fact: MIG 3U misrepresentats the report, which states:

Erflogene Geschwindigkeit 493 km/h, auf Normaltag und Garantileistung umgerechnete Geschwindigkeit 498 km/h im 0 m.

They have flown 493kmh at altitude of 440m, which was not yet corrected for German Standard Day conditions or the Guaranteed output of the engine. Bench tests confirmed engine was developing 45 PS less than it should have.

Nope.

Fact: Boden and Hohenlader are just generic names for MS and FS speeds, present on all DB 601/605/603.

The supercharger has two . US trials of captured Bf 109E, later Rechlin trials of Bf 109G-6, G-14 also run with fixed supercharger speeds, something which is easily done on the DB 60x series with hydraulic coupling by bypassing the barometric control.


Nope.

DB 601A-0.

"Gemischung durch: 1 Bosch PZ 12 HM 100/11 Einspritzpumpe für 12 Zyl."

"Lader: einstufiges Schleudergeblaese mit barometrischer regelung"

http://kurfurst.org/Engine/DB60x/datasheets/601a0.jpg


Nope. French trials for example with Bf 109E-3 WNr. 1304. (DB 601A-1, so lower power at 1,3ata) show 495 kph at about 500 meter altitude.

http://kurfurst.org/Performance_test...09EWNR1304.jpg

All figures match the V15a performance using Höhenlader well, indicating the tests

"Everything else", well.

WNr. 1774. 498 kph, E-1, "DB 601A", 1,35 ata. 1060 PS.
WNr. 1791. 475 kph, E-1, DB 601A-1, 1,3ata 990 PS, ie. 70 PS less power. "figures are not corrected for guaranteed engine output"
WNr. 1792. 467 kph, E-1 DB 601A-1, 1,3ata 990 PS, ie. 70 PS less power. "figures are extrapolated graphically to 0m" and "figures are not corrected for guaranteed engine output"
WNr. 1304, ca. 485 kph, E-3, DB 601A-1, 960 Hgmm (ca. 1,3 ata). 990 PS, ie. 70 PS less power. With estimated position error curves: +/- 15 kph on speed.
WNr. 2404, 464 kph, E-3, DB 601Aa, probably 1,35ata. Conditions unknown. Curves clearly show single speed supercharged performance with no appearant hydraulic curveture. Figures closely match WNr. 1774. Höhenlader performance (extrapolating to about 460 kph at SL)


Calculating the speed of the the Spitfire I at +12lbs the same way as done in the V15A report:

Density at sealevel: 1.225 kg/cubic meter
Power at sealevel at +6.25lbs: 880hp
Power at sealevel at +12lbs: 1180hp
Speed at sealevel at +6.25lbs: 280mph

r = ((1180/880)*(1.225/1.225))^(1/3) = 1.103

V0 = 280mph * 1.103 = 309mph = 497kmh

However, that is a crude, unaccurate and partially wrong way to calculate it.

As shown above, they are not facts but misrepresentation of the facts.

Your theory is basically this. Messerschmitt built a prototype for the Bf 109E series, which achieved around 500 kph with the the engine cowling still unpainted, without fuel injection and without a multi speed supercharger, which (then appearantly the Americans got hold somehow of another Bf 109E and oddly tested it the same way as the Germans theirs... :D ) . They have noted in their report that due to time constraints, they could not yet fit the proper exhausts and air intake, so "further increases in performance are possible".

Then they supposedly went on improving it with a oil cooler of the size of an elephant, that chopped down 40 kph (!!! :D :D) from top speed, but strangely enough only at low altitude :D, they added direct fuel injection which probably made the engine even weaker. Happy of good days work, and that they achieved no less than 40 kph speed loss, they decided to put that new version into production. The legal and financial department went nuts too, and decided to give legal guarantees for reaching a performance that according to you, was impossible to achieve. Save for a few odd examples that landed in French, Swiss hands which matched V15a figures finely.

Extremely likely, yes.

Any observations on the "prototype" Bf 109E overlayed with the Swiss trials of WNr 2404?

Well, we have the test data of the V15a showing clearly a supercharger with two fixed speeds instead hydraulic clutch and this is supported by Von Gersdorf et.al. Any source can contain errors or projected things which happened later, this is why any source should be contested. In this case your source, what ever it is, is easily contested because the characters of the hydraulic clutch are not there and Von Gersdorf et.al. can be seen as more credible source (generally the secondary source is seen more credible because it's better contested and refined, like in wikipedia).

So does this US trial of captured Bf 109E. Does it have "two fixed speeds instead hydraulic clutch"?

http://www.wwiiaircraftperformance.o...e-109E3-US.jpg

And so does this German trial of captured Bf 109G-6. Does it have "two fixed speeds instead hydraulic clutch"?

http://kurfurst.org/Performance_test...G-6_DB605A.jpg

And so does this German trial of captured Bf 109G-14. Does it have "two fixed speeds instead hydraulic clutch"?

http://kurfurst.org/Performance_test..._viaGGHopp.jpg

I don't see "Von Gersdorf et.al." anywhere here. Only your speculations, which happen to be repeating the same as that of a certain figure called Harri Pihl. Who has also kept refusing posting his sources, when cornered. ;)

The E-1 was then still under developement and came out much later.


No anykind mispresentation there, 485kmh at 0m can be read directly from the chart and calculation is based on density 1.175 kg/cubic meter.

These engines do not have gear change nor pressure drop until FTH. Only a altitude range where the supercharger speed is variable.

Regarding the rest, many organisations have done tests poorly or intrepeted tested data poorly. You just pick the ones which suit to your agenda.

Over and out until something relevant is posted.

No need, just making the point. I am happy to liase with pstyle on it though, I would like to just make sure that the 109 is correct in HSFX, of course would seek necessary approval from 109 jockeys who have a similar historically accuracy first agenda to me.

Yes, but this one clearly doesn't make 500kmph on the deck (290mph or 464kmph) and has a maximum speed of 340mph (544kmph). That's about 15mph slower than the Spitfire top end and only 6 or so kmph faster than the Spitfire on the deck running at only 6.25lbs of boost. In fact, 290 mph is only slightly faster @ sea level than a Hurricane I @ 12lbs + 3000rpm.
Now, I'm not suggesting that the gap in speed between the Spitfire and 109 is that large, but it's certainly wildly different from your chart. Given that you stated that the prototype you quote is unchanged from the production E-1, how can you account for this discrepancy?

The trouble is, there's this whole 'big lie' about the 109 advantages on the Spitfire (you perpetuate it, that the 109 can out climb, out dive, out speed, out gun and out turn the Spitfire) Some of these are true or course, but not all like you indicate.

I can post the paper for you when I get home, though you have already seen it in full (transcribed) on my site. The Blatt 3 part pstyle was missing is actually there, its the 3rd page that covers the second part of point three and the rest of point four (the typed text part spread through multiple pages), but for reasons of convinience I have ommitted the header for the rest of the pages, which would break the text flow and would say just the same, well, except for "Blatt 3" instead of "Blatt 1" and "Blatt 2" in the right upper corner. ;)

Nope, its just another 109 that has it's hydraulic supercharger set up to give fixed gear ratios. All it needs is to disable the second oil pump in the hydraulic clutch to get a fixed low gear, and then to set the second oil pump in the hydraulic clutch to get a fixed high gear (at minimum slip). Looking at the other testing papers, it was commonly done to reduce the margin of error in the measurements.

BTW if you look at the paper carefully you will see that no low level speed measurement was made, the lowest actual data point measured in low gear was 336 mph at 12k feet. Anything below was simply extrapolated (and obviously with a large margin of error, given the very few points available for extrapolation)

Well for one we have absolutely no idea about the testing conditions. Without these, it's rather pointless to compare different tests. The aircraft does show very different results from the rest, which can mean the testing conditions may have been different, the airframe or engine was subpar and so on. What "109" is this anyway?

I don't perpetuate that. Especially, since much of this data, for example climb rates are missing for both aircraft.

cheers Kurfurst.

Can someone tell why these 2 German documents have the Vo as 476-476kph and 466-467kph.

http://www.wwiiaircraftperformance.o...109E1-1791.jpg
http://www.wwiiaircraftperformance.o...109e3-1792.jpg

It says underneath, that although those speeds are re-calculated for normal temperature and correct manifold pressure, they are not corrected for the guaranteed engine perfoamance yet.

Seems to me that no matter how I look at that, the guaranteed performance by Mtt is rather theoretical.

Good point.

Besides the fact that both of these papers show 109s with the 990 PS DB 601A and not 1045 PS 601Aa....

And, despite the weaker engine operating at an unknown power, the first test (476 kph) still just satisfies the guaranteed specs of Messerschmitt (500 kph +/- 5%, that is: anything between 475 and 525 kph is O.K.).

Thanks Robo. The speeds are not within the +/-5% tolerance being in the 7% range.

Another point to discuss.

Someone said the, iirc, that the trim tabs on the Bf109 were set for a speed of 400kph. This would be ~80% of top speed. This would be max continuous speed would it not?

How much time would be spent at max continuous speed? The a/c wouldn't be at this speed when escorting the bombers but at a lower speed for which the a/c would not be trimmed for. I would think that the a/c would be trimmed for a speed the a/c would spend more time at, possibly 300-350kph. At these speeds, it would be much easier on the pilot.

Kurfurst once posted some test data on the Bf109G that was a plot of the top speed of several a/c. There was more a/c below the guaranteed top speed than above the guaranteed top speed. Just something to think about.

In other words the Germans took it for granted that there was a possible variation of 50 km/h in guaranteed speed at sea level, which is no form of guarantee at all when life or death in air-to-air combat could rest on very small margins of speed. It also means the top speed of a 109E at FTH could vary by an even wider speed range - anywhere between 532 km/h (330 mph) to 582 km/h (361 mph).

... and here it is. But don't expect anything new...

Why do you continually show V15 data and not data for the E-1,3 Kurfurst?

Referring "Blatt 2" important results concerning speed etc. are reported on "Blatt 6".

Please can you provide "Blatt 6", too?

Regards Varrattu

Oh, sorry.

http://kurfurst.org/Performance_test...15a_blatt6.jpg

@ Kurfürst

Thank you.

Varrattu

There are a number of issues with the outlyer 109E 500 km/h sea level top speed:

First of all the Baubeschribung 500/570 Km/h speed curve does not map any known engine power/alt curve: These either have the characteristic bulge associated with the hydralic clutch or the notch type with two speed superchargers where as the curve showing 500 Km/h at SL and 570 Km/h at altitude in the Baubeschribung has a straight line between these points. So which DB601 in a series Me109E had this power/altitude characteristic? None that I have seen published.In addition the date of the the Baubeschribung is stated as "circa 1939"and reference made to the Yugoslavian manual. So this looks more like some early marketing material supporting Messerschmitts export activities which also predictably for marketing material includes a caveat of plus minus 5% which would then place the more realistic speed performance of around 475 Km/h within the guaranteed range.So to conclude, the data supporting 500 Km/h SL speed either references prototype data or refers to some early marketing material. In addition, it looks like estimate for the "guaranteed" engine data coming close to 500 Km/h for the V15 prototype is for 1,35 not 1,3 ata.

Moving then to some more realistic speed estimates based on what could be expected of a series type aircraft at 1.3 ata: Note that the C++ simulation data for the high and low altitude speed of the +6.25 and +12 boost Spitfire is quite consistent with historic data. Using the same principles for calculating the Me109E low level speed the result also yields around 570 Km/ at altitide but at low level the result is around 475 Km/h not 500 Km/h. These curves were calculated using the actual historic series type engine data and consequently show the effects of the hydraulic clutch, something missing from the 500/570 Km/h chart. I'm sure the usual suspects will question the validity of the C++ simulations but as an answer to that we have the Me109E figures posted by HoHun on the All About Warfare forum (www.allaboutwarfare.com) and as can be seen the calculations agree remarkably well. In addition one can conclude that both calculations agree quite well with the actual measured top speed posted earlier by Al Schlageter.

Finaly, it's interesting to note the type of evidence evaluation practiced by some in this forum: There was a mountain of evidence supporting 100 octane that was dismissed as inconclusive and now we are expected to swallow a molehill of evidence for 500 Km/h sea level top speed when most data, calculated and test measurements point to something around 475 Km/h.

Talk about double standards....

The Baubeschribung curves are obviously simplified, drawing a straight line between low level and FTH performance. Again, nothing uncommon in that, Rechlin did the same thing for a tested G-1 chart:

http://kurfurst.org/Performance_test..._G1_kurven.jpg

All, in fact:

http://i38.photobucket.com/albums/e1...ontrolunit.jpg

Unsurprising, since both the V15a flight tests results and guaranteed specs in the Baubeschreibung are for 1.35ata.

The sillyness lies in that some people want to compare these 1.35 ata results to 1.3ata, uncorrected figures, and the fact that uncorrected results achieved with the less powerful DB 601A-1 at 1.3ata / 990 PS are irrelevant when modelling our 1.35 ata / 1045 PS Bf 109E equipped with the DB 601Aa.

The rest of your post is irrelevant.

BTW it's worth comparing the V15a (WNr. 1774) results with the speed results with a Swiss export Bf 109E-3a. The reports show remarkable similarity in the top speed achived at altitude with the original VDM propellor of J-347 (572 vs. 564 km/h at rated altitude), especially when taking into account that J-347 already saw considerably use. However the low level speeds diverge greatly (498 vs 464 km/h at 0m altitutude). Note that the low-level performance of V15a with the Höhenlader (high altitude supercharger speed, or 'F.S gear' in British terms) shows good agreement with J-347 at both high- and low altitudes.

This would suggest that J-347`s level speed results were achived with the Höhenlader in operation and agree well with the results of Bf 109E-1 / V15a WNr. 1774.

Also note that the Baubeschreibung agrees well with the V15a results, but the curves are bit more simplified (mean avarage results).

http://i38.photobucket.com/albums/e1...1774vs2404.jpg

Holtzauge, that pretty much sums it up.

German speed graph of a Bf109E with a DB601Aa engine.
http://www.allaboutwarfare.com/forum...e=post&id=2042

Very cool! I just joined the All About Warfare.. First thing I noticed was butch2k is there! I was wondering where he had gone! Al, did he ever finish that book he was working on? Or do I have him confused with someone else?

Swiss.

http://kurfurst.org/Performance_test...J347/J-347.jpg

Yes, I think the case for 500 Km/h SL speed for the Me109E is rather weak.

I don't fly CloD but used to fly IL2 some before, mostly Me109's and Fw190's so I'm not interested in porking them in any way.

What I do want is as realistic performance as possible in any sim which is not something you get if you like some people in this forum consistently take the inside envelope of any allied data and the outside envelope for the Me109 if you get my drift. None mentioned and none forgotten ;-)

I don't know about any book but the site as such contains some nice info and HoHun has posted a lot of interesting speed and climb analysis for a number of aircraft so the site is well worth a visit.

To the best of my knowledge we use different ways to calculate performance but from what I have seen so far we seem to arrive at quite similar conclusions. My C++ simulation also allows incremental integration of data so I can model transient flight conditions like dive and zoom and instantaneous turn etc.

There was some diff btw the 109 exported in Switzerland and the original E. Notably in aerodynamics.
I don't think you can make a comparison without taking this fact into account.

I will be delighted to hve a look at your C++ "simulation". Pls show us the core engine instead of hijacking any scientific credits. Let me guess... inviscid, incompressible and lift line theo with linear curve discretisation? lol

What kind of difference do you have in mind?

Well of course, since we have your toy excel sheet against thoroughly documented test data! :D :D

I hve in mind the guns (barrel for sure). I think the rad were different. But I need to check this. There is also a good article on the net (in French probably) if you browse around "bf109" and switzerland ("Suisse"). Will try to have a look.

EDIT:
Guns for sure and prop

Well you guessed wrong! I actually did a post a while back arguing for the introduction of subsonic drag rise which is missing in CloD but modelled in the C++ simulation. Modelled a Spitfire Mk1 and showed that the speed build up in CloD in quicker than it should be because compressibility effects are missing.

Seeing you seem to be such an expert perhaps you would be so kind to point out what is wrong in my Me109E speed/alt chart and how it really should look like?

Yes I will check that, I had a good (IIRC German language) book about Swiss 109s, which helped me to ID J-347's WNr. and service record.

As for the gun barrels, I am not sure - one of the tests being waved about is explicitely about measuring the speed diff. between guns present/not present, and it's about 1 km/h.. I'd imagine different gun barrels amount to even less. ;)

Rads look interesting though, this might account for something, but again, looking the Swiss test results, the difference is only about 8 kph at VDH, which from my experience, is an extremely good match for a serial production plane compared to the guaranteed specs!

Well for one it probably has wrong data.. guessworked drag, guessworked wing effiencies, guessworked propeller effiency, manipulated until it fits one's agenda. :D

As Tagert said, garbage in... garbage out.

BTW, care to tell why you disappeared from allaboutwarafe forums? I am sure it's hell of a story. :D :D :D

The core.. That's not too much to ask.

I think people are aware by your modus operandi by now: If you don't like the message then discredit the messenger.

Me "disappering" is for no more sinister reason than for working on a book project. Believe me it's much more satisfying than arguing about your doctored data or sparring with your mathematically challenged pal Crumpp!

So if my Me109E data is so totally wrong then I guess this means that HoHun's charts are off the wall as well because we get the same results, i.e. around 475 Km/h on the deck. Garbage in and garbage out in both cases huh?

BTW: Concerning disappering, in your case we know the answer don't we? Permanently banned from a number of forums and as editor in Wikipedia. That sure is one hell of a story! :D :D :D

Actually it is. I'm going to use the C++ results in a book project so I'm not going to sink my own project by posting my code before that :)

Nobody needs to discredit you.

.. but you seem to need to discredit others. :D

It is. It doesn't match tested results, does it?

I would love too see those test results.

Seems to me like you are confusing the calculated speed of the V15 prototype at 1.35 ata or the caveted Messerschmitt marketing material with actual test results. The only test results I've seen point to 466-475 Km/h.

You still have not answered the question: How do you account for HoHun's estimate of 475 Km/h?

And that is why we only see the V15 prototype data and not data for production Bf109Es.

It takes a great deal of dishonesty and/or confusion to claim the V15a speeds are calculated.

"An Bf 109 V 15 a, der Mustermachine für die E-1-Serie, wurden die Geschwindigkeitsleistungen erflogen."

Can you translate the above please?

Trouble is, Messerschmitt's type specification sheet ("marketing material") is the official specification for the aircraft, and was to be met by all similar Bf 109E in the Luftwaffe within +/- 5%.

Well again it takes a great deal of dishonesty and/or confusion to claim not having seen flight test results, when the V15a flight tests have been posted in their full just a couple of pages back.

You should ask HoHun, but as you say: it's an estimate. For a different engine.

Curiously though, the French were hitting the exact same speeds at low levels (ca. 493 km/h) with their captured Bf 109E-3 as the Germans did with the E-1 (V15a)

http://kurfurst.org/Performance_test...09EWNR1304.jpg

It will be amusing when next time, you will claim you have not seen this either.

But, oh boy I forgot, you have your own charts. :D

Now let's see how speed figures claimed by British propaganda measured up to actual speed measurements... ooops, not very well it would seem! I am really looking forward to see a historically accurate Spitfire Mark V. ;)

I do read German and therefore I know the difference between what was flown and what was projected for the V15 prototype: "Blatt 6" shows about 485 Km/h for the FLOWN 1.3 ata value and the ESTMATED 500 Km/h value for "Geschwindigkeiten bei Garantierter Motorlesitung" 1.35 ata as a dashed line. So who is being dishonest now?

Concerning the French test it looks like very few data points and none at SL as I can tell so your claim that this supports the 500 Km/h seems a stretch.

So HoHuns and my calculations are for "a different engine" and can be discounted as "estimates"?. Quite interesting that this method of calculation works well with the Spitfire and also mirrors 466-475 km/h Rechlin test results for the Me109E SERIES aircraft no?

I see you added some Spitfire data now. I assume it's safe to bet that this is the absolute rock bottom worst data you were able to find on the Spit, right?

Here is the document mentioned earlier.
http://www.kurfurst.org/Performance_...catter_web.jpg

13 a/c

4 below spec -5% > 31%
6 below mean > 46%
3 above mean > 23%

The average for all the a/c is well below the mean.

Applying this to the Bf109E would give an average speed of ~485kph.

That's not really a question, it is still you (and you are doing it rather poorly as usual), so continue translating, maybe you are better at that - its funny you have not translated the first part isn't it. :D

2. Stoppflug.

Ergebnis: Erflogene Geschwindigkeit 493 km/h, auf Normaltag und Garantieleistung umgerechnete Geschwindigkeit 498 km/h im 0 m. Umrechnung siehe Blatt 5.

For those who do not wish to bother much with Holtzeuge's incoherent lies, here's the deal (as noted by the report clearly):

The aircraft (V15a), identical in all to series production E-1 flew low altitude speed trials on a four way track. The engine was bench tested as well (actually the ONLY test I am aware was this through), as was found to develop 45 PS less, and developed only 1.31ata in fligth instead of 1.35. Calibration flights were also made.

The 'raw' data collected (493 km/h at 0 m) was then converted for standard conditions: German Standard day atmospheric conditions, and normal engine power. The result was 498 km/h at 0m. The methods are clearly visible at the end of the report.

This is of course entirely normal, almost all Spitfire etc. tests for example do the same thing: correct the figures to normal boost ratings, and adjust for (British) Standard Day conditions. Otherwise, they would be useless for comparison...

Holtzeuge claim is basically because the flight tested data was converted (as usual) to standard conditions it needs to be dismissed because it's an 'estimate.'

:D :D :D

Well they ARE estimates and they are for a different engine and different boost... :D

Nope, your calculations are not interesting at all. :)

Oh, not so finnicky about 'marketing brocheres' any longer, are we? :D

Ok, I just remembered butch2k's names from years ago.. He was a very informative and level heading logical guy from what I remember.. There was another guy with a name similar to his.. B something, maybe he was the guy writing the book?

By the way your name rings a bell too.. I seem to recall seeing your C++ stuff a few years back.. Very neat stuff! I have some of Henning Rush's stuff posted at my website.. i.e. www.flightsimtesting.com and would love to post some of yours too! What format is your output files? Simple text I assume? Could I get a copy?

I see you have 'experience' with Kurfurst too! ;)

Well... and naming the eq. that you use is that so much classified that you can't even do it?

The French test shows about 494kmh at about 550m and and power chart gives about 1010ps at 550m, these values give 482kmh at sealevel with 990ps.

The outliers, like the sealevel speed in the V15a test, are usually caused by measurement errors. And given the fact that speeds match better with other tests at high altitude, it is probable that something is not right in the V15A measurements (error can be anything; failing device, typing error, calibration problem etc.).

Seems there's then good agreement between the German tests with the E-1 at 1.31ata and the French tests with the E-3 at 1.3 ata then even according to Harri's own estimates.

Of course it should be kept in mind that the final E-1 results were corrected to 1.35ata and Standard Day, and resulting in 498 km/h, and that our E-1/E-3/E-4 models have 1.35 ata.

Good point. Since the two brief trials of 467-475 kph you mentioned fell well out of the official and other measured tests, and they note that some necessary corrections were not made (the first trial mentioning that the SL speeds were simply graphically extrapolated to SL, and both trials noting the figures are not yet corrected to guaranteed engine output) it's likely the scatter is caused by measurment errors.


Which can be entirely ruled out given the fact that the low altitude measurements with the V15a were done on a four way record track, the aircraft having flown in four directions, and the (known) distance covered was timed. This method is by far the most accurate and eliminate all possible instrument errors.

On the other hand this thread is about how the Spitfire I and II series performs in CLOD 1.08, which has now been supplemented/superseded by 1.09, not about Kurfurst's interpretation of 109 data which we all know will be skewed in one direction - how about another thread for that?

Fact is neither patch has provided authentic Spitfire performance, with or without +12 lbs, and there are still chronic overheating issues that ATAG_Dutch has helped alleviate.

Thread title says: " Spit/109 sea level speed comparisons in 1.08 beta patch"

Updated paper with French trial results included.

http://i38.photobucket.com/albums/e1...psd822ce28.jpg