109 e4 performance
 

I know I'm gonna get flamed for this... But is anyone else having problems staying sliced vs spitfire mk2's online? Seems to be the case that one on one the 109s can't hold their own against the mk2's and the only option is to run for ur life.... Other than that the 109 is a joy to fly! Oh maybe one thing can be done agains the mk2. That is to split-s, i can shake the spit off my six but can't turn it into an advantage. To the 109 pilots out there, is your experience online similar?

read here
http://forum.1cpublishing.eu/showthread.php?t=25956

Mh again something on the proppitch.

I noticed that during automatic pp control on the clock moves very slowly. Ok this may be due to the mechanism behind (somebody has some knowledge on the proppitch speed during automatic mode?).

But what I think is wrong is that during manual mode the prop pitch is as slow as was the 109E3 before this patch. I think this is wrong and in manual the speed should be like that of the 109E3 that is 4sec for one hour on the pp clock.

I am getting 6 secs per Hour of clock movement on all types in AUTO or Manual. That represents 1.0 deg per sec of actual blade angle change. Ideally we should be seeing 1 Hour of clock movement in 4 seconds ... representing 1.5deg sec actual blade angle change.

the e4 was never as fast as the spit anyway so there lol :-P

Mh. I am quite often flying the E3 and with the latest patch the pp is really fast. I did not measure it but it seems to be about 4sec per 1 hr.

6 sec

I think it's pretty well-known that the Spit Mk 2 is getting historical performance while the 109s, hurricanes, and Spits Mk 1 are not performing as well as they should.

I personally just avoid servers with the Mk 2.

You mean infinite turn perf and zoom better than the 109 as being historical ? No thx !

Cutting somebody arm does not stop him from sneezing herr Doctor ;)

109 and hurri are just fine IMHO.

so how fast should a E4 go level flight ?

no idea if this site is accurate or not ? http://www.spitfireperformance.com/spit1vrs109e.html

The story is much deeper than what is presented.

The newest data on the Bf-109E on that site is December 1939.

The Bf-109E is not using C3 fuel or a CSP.

Both were in use during the Battle of Britain.

You can sum the truth up as "Some Spitfires were faster than Some Bf-109's and none of them under all conditions....."

Is is quite hard question actually how fast 109 E-3/E-4 was at the deck.

Most data claimed for 1.3 Ata power ( 5 minut emergency) - 460-467 km/h

Probably it would be at 1.42/1.45 Ata (1 minut emergency) about 480-500 km/h.

German manual for E-3 claimed 500 km/h at deck.

Spitfire MK1 at 6 lbs reached ab. 460 km/h and at 12 lbs ( 5 minut emergency) reached 505 km/h.

Hurricane MK1 at 6 lbs reached 426 km/h and at 12 lbs reached 460 km/h.

Well, speed depends on altitude, but here's a test conducted by the French in 1939 on a captured Bf 109E-3 that appears to reach approximately 490 km/h at sea level.

Hi all :grin:

I think the */B Versions of the BF109s are a little bit slower due to the bomb rack. When i test a flight at 1000m and 1.3 ATA and 2400 rpm i reach 420 km/h. Thats 25 km/h to slow to original documents from 4.7.1940 see here:

http://www.beim-zeugmeister.de/zeugm...ndex.php?id=52

Official Bf 109E specifications, guaranteed by manufacturer within +/- 5%. All Bf 109E accepted by the Luftwaffe had to fulfill these specifications for acceptions within the above limits.

http://www.kurfurst.org/Performance_...chreibung.html

http://www.kurfurst.org/Performance_..._Bau_speed.png

In short, our Bf 109Es are 40 km/h short of speed at low altitudes. FM bugs so far prevented to verify if they can reach 570 at altitude (did not test with latest patch. No TAS indicator either)

Spitliarperformance site as usual reports only speed at 30-min ratings, not maximum outputs.

Is this chart with Notleistung?

I am a bit confused. I currently thought that 490 should be normal speed without Notleistung. But now I have some doubts.

Notleistung?

OK... Got it on Wikipedia...Emergency boost.

I am a great 109 fan and I would like to have all the planes in the sim as close as possible to the real thing. Therefore I don't think it would be wise to get data from the manufacturer specs :grin:

Lol, Robo. Are you a manufacturer? :grin:

That is the best standard in the aircraft industry.

That is the performance Mtt's guaranteed by contract to the RLM its airplanes would perform. If an airplane did not fall within that +/- 5% then the RLM did not pay for it or accept it as one of the airplanes it purchased from Mtt.

Each airframe was test flown before it was accepted for Luftwaffe service and it had to meet that minimum specification.

Alright, I think we should use the data specified by the manufacturer when they tried to get that contract then. ;)

If it is a question of credibility, between the manufacturer data and that "test" done in France, I trust more in the manufacturer's, for two reasons:

1) if you read in the detail the french test, is clear that it was done far from the conditions you want for a test.

2) I havent heard of a single LW report complaining about the manufacturer's specifications being wrong.

Cheers!

Well, manufacturers tend to stick with margins specified and use them, if they have the quality system giving them the ability to mangage the narrow gab. If 500km/h +/-5% on ground level was specified, I would expect the standard plane to leave the shops testified to be able to reach 475km/h, but not one km/h more.

Really???!!!?

:grin:

That is my opinion, too.

They wouldn't complain to you, dude with a 109 in the avatar ;)

It definitely gets fixed if it does occur. Focke Wulf had an issue with one of its subcontractors, Dornier (NDW) not meeting specifications.

It was discovered when the Luftwaffe was rejecting a large number of aircraft. The complaint was excessive vibration and fuel consumption. It generated several reports on the issue and was fixed promptly. It caused NDW to suffer greatly increased oversight and they almost lost their contract.

That is not it works building airplanes. You can get close to the lowest common denominator building a toaster maybe?

That's fine information regarding the inferior quality of a component supplied by 3rd party, but does not say anything about the overall performance, especially top speed. Of course, quality of the components matters a lot and if they all meet standards, it is very likely that the aircraft as such will meet them. BUT manufacturer's specifications are more likely to be a target, not necessarily reality. I highly doubt that they would stretch brand new engines to see if every plane goes 500 km/h on the deck, returning them to the manufacturer if they wouldn't. :D If the engine ran fine and within specs, they were happy. It was close enough to the specs, some particular aircraft met them OK, but as for the sim, -4 or -5% seems to be reasonable.

The point is that the graph posted by Kurfurst is what the manufacturer would like to achieve, but we all know how it goes in real life, do we? I agree that in Germany it was more strict than e.g. in Russia or Italy (:-P:-P) This is my opinion and I respect yours. But who are we? :)

There were 2 types of engines used by LW - Db601A and DB601Aa which had little different power output.

Db 601A - sea level
1 minut emergency (2400 RPM at 1.4 Ata) - 1100 PS
5 minut emergency (2400 RPM at 1.3 Ata) - 990 PS

Db601Aa - sea level
1 minut emergency (2500 RPM at 1.45 Ata) - 1175 PS
5 minut emergency (2400 RPM at 1.35 Ata) - 1015 PS


Standart 109 E-3 with Db601 at 1.3 Ata 2400 RPM (5 minut power) reached at sea level - 467 km/h ( radiator 1/4 open)

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

http://kurfurst.org/Performance_test...MP16feb39.html

It is good agreement with Swiss 109 E-3 Db601Aa tested with different propellers:

http://kurfurst.org/Performance_test...-347_speed.jpg

Sea level speed - 467 km/h with standart propeller

Quite close with tested captured 109 E-3 by French :

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

So it could be that with Db601 Aa at 1.45 Ata 2500 RPM (radiator close?) - 1 minut emergency power 109 E-3 reached 500 km/h like in German manual:

http://kurfurst.org/Performance_test..._Bau_speed.png


Interesting is that at low level 109 E-3 need 5-minut power output with speed 467 km/h comparing to Spitfire MK1 at 6 1/2 lbs ( 1/2 hour limit) - 455 km/h. Db 601A had 990 HP at 1.3 Ata where Merlin III had 880 HP at 6 1/2 lbs at sea level.

:grin:

concerning this: I think it would have been a dangerous policy from an industrial point of view if they aimed at 475 kmh while they guaranteed 500 +/-25 kmh.

We know that during production of the plane (all parts, some coming from suppliers not under quality control of the Bayrische Flugzeugwerke) and the engine (all parts, some coming from suppliers not under quality control of Daimler-Benz) variations occur (that's why each part will have its own specs +/- acceptance margins). When all parts assembled it will lead to a performance that will vary from one plane to another. Now if they had aimed at being at the lower limit they would have ended up with planes that would not have met the specs and therefore increased the number of planes rejected by the customer. This is imho something that someone who wants to run his company profitable wants not to happen.

If one reads the chart by the French one should assume that they could have reached about 480 kmh on deck. At 500m they are at 494 kmh.

No it is NOT what the manufacturer would like, hope, might, or any other passive, obscure description.

As it is labeled, it is what the manufacturer guaranteed and what was accepted by the customer.

Sure it does. You do understand that these are complicated machines and they don't just roll off an assembly line into the squadron ready line.

A newly manufactured aircraft is one of the most dangerous things in aviation. It is unproven.

A very thorough inspection is completed before the first test flight. The manufacturer will put the aircraft thru a test flight period to ensure it reaches its numbers before turning it over to the customer who again goes thru their own prescribed regiment of test/inspections before accepting it.

When an airframe reaches the end of the assembly line, it was not uncommon for it to remain there for a month or so as it was tweaked and refined before being accepted.

Nest of Eagles: Messerschmitt Production and Flight-testing at Regensburg 1936-1945", de P. Schmoll, Classic Publications (2010).

There is certainly some changes from the early 1939 data.

I really don't think development was static in Germany for 18 months before the Battle the Britain.

Otherwise we would have to believe that Germany exported more powerful engines than they used in their own aircraft. That does not make any sense and would be a first in the history of the world. :grin:

We don't know the exact conditions, perhaps it is the performance with the automatik propeller?

Auszüge aus Flugzeugdatenblatt (aircraft data sheet) Bf 109 E-1, E-3 nach L.Dv.556/3 @ http://www.rolfwolf.de/daten/E4/Emil.html

Motorleistungen DB601A

Kurzleistung (1 min) 1100PS bei 2400 U/min 1.4 ata

Startleistung 990PS bei 2400 U/min 1.30 ata

Steig/Kampflleistung 910PS bei 2300 U/min 1.23 ata

Volldruckhöhe 4000m

How do the speeds match for:

Höchstgeschwindigkeiten in Steig/Kampfleistung

0km - 460km/h

1km - 480km/h

2km - 500km/h

3km - 520km/h

4km - 540km/h

5km - 555km/h

6km - 555km/h

7km - 550km/h

If the Höchstzulässige Horizontal-Bodengeschwindigkeit (Maximum horizontal ground velocity) is 485km/h, how can the max speed at 0km be 500kph?

500 km/h could be probably reached with DB601Aa motor which had 1175PS power output at sea level at 1.45 Ata 2500 RPM.

These is 75 PS more then with 601A ( 1100 PS).

Also these data above is probably for old supercharger (4.0 km FTH).

There are data where 109 E-3 reached - 467 km/h at deck - so a few km/h more, so probably also maximum speed ( at 1.4 Ata) would be little higher then 485 km/h - about 490 km/h. It could be difference in radiator position.

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

These is power output with newer supercharger which rised maximum speed at FTH - with old there was 555 km/h with new one it was 570 km/h.

http://i42.tinypic.com/1zou9v8.jpg

http://kurfurst.org/Engine/DB60x/datasheets/601a1.jpg

In perfect world: sure. In our world and especially during the war: no.

Again - 500 +- 5% means they tried to achieve 500 but it was more likely that most of the time, they made it closer to the -5% in so called real life. I am not saying that they were failing to stay within margins.

Oh yes, please read again what I wrote before, thank you. ;)

Of course, I don't disagree at all, this is all well known facts and we can go as far as comparing the later 109 models leaving various factories. Of course there was a difference and variation in real life. The question is what data to use in order to have the a/c close to the real life performance. My opinion is that manufacturer's data should be considered as on the optimistic side.

There are other ratings the engine was approved besides climb and combat power....

We know for a fact, C3 fuel was in use during the Battle of Britian.....

Automatik propellers (CSP) also were used during the Battle of Britian that were not in use in February 1939 as the the other data is dated.

Pick your poison....

Noted and accepted.

For the discussion, what is your aviation experience and background. Not that your opinion is not valid, just so we all know where it is coming from.

C3 fuel was used only in Db601N engines not in DB601.

Also automatic prop pitch for 109 E didn't change its maximum speeds.

So i think all difference at sea level speed is in radiator settings and type of engine - Db601 A or DB601 Aa which had more power at the lower alts then 601A and surly difference in tested planes.

You all realize that the French test obtained about 494 kph at 600m altitude and in extrapolating to 0m something around 480 kph? At rpm = 2400.

The pression d'admission about 1000 (unit I cannot read). My guess is that they speak here of ATA pressure. Just not sure what kind of unit they used as I cannot decypher the scale label.

Here is French 109 test raport :

http://kurfurst.org/Performance_test...formanceT.html

We got from French test :

With radiator open

2.5 km - 490 km/h - 2400 RPM - 960 mm. ( 1.3 Ata)
5.0 km - 520 km/h - 2400 RPM - 870 mm.


With radiator close:

5.0 km - 570 km/h - 2400 RPM - 880 mm.

There is 50 km/h difference between radiator open and close at 5 km alt.

In chart there is about 475-480 km/h at 2400 RPM at 1000 mmHg which mean that test was done at ab. 1.35 Ata - probably radiator somewhere in the middle position (looking at 5 km maxiumum speed - 550 km/h) so with higher ATA then in previous data ( 1.3 Ata - 460-467 km/h).

So it confirmed previous data for E-3

1.3 Ata

0- 460-467 km/h - depend of radiator settngs, and sort of plane

1.4 Ata (Db601A) - about 485-490 km/h

1.45 Ata (Db601Aa) - 500 km/h.

109 E-4 would be little slowier then E-3 beacuse of more draggy windscreen - it could be about 5 km/h slowier ( the same E-3 with new windscreen)

The chart has at 600m a pressure of 980 mmHg pression d'admission. Extrapolating it would be at 990 mmHg at 0m. The speed is clearly close to the 480 kph when extrapolating the chart to 0m, perhaps at worst 478 kph.

5 kph velocity loss seems a bit extensive with respect to the new windscreen.

They even did not measure any difference with guns installed or not (so including the effect that for level flight higher angle of attack would have to be chosen due to increased weight of the guns).

Pression d'admission translates into inlet pressure or manifold pressure so I think this is ATA setting they used.

http://dictionary.reverso.net/french...'admission

+/- 5%.....

Of course it is valid, you're extremely kind to take it in account :grin: Much appreciated.

Now tell us how do you think the E-4 performed like.

That is range of cca 50 km/h. Do you think there was a Bf 109E-4 able to fly 525 km/h under citied circumstances?

Yea it such case E-3/E-4 would be faster then 109 F-2 which can't be true.

Try be more real.

I think 500 km/h is the highest sea level speed which could be achived by standart 109 E-3 with Db601 Aa engine and with 601A it could be even slowier ( ab. 490 km/h) with 1 minut emergency power.

You are confusing manifold pressure with atmospheric pressure, I believe.

If you read the report, it says nothing about any of the data being converted to standard conditions. Therefore it is raw data for the atmospheric conditions given.

http://kurfurst.org/Performance_test...formanceT.html

When you convert the performance to standard conditions, the results will be faster than the raw numbers in the report.

That is my opinion, too. I am trying to explain to Crumpp that the 500 km/h graph he's referencing as 'guaranteed' is way too optimistic.

It would be great to have actual variation in performance of certain type modelled in the sim.

Sure it would be able too. All aircraft performance is a percentage range over a mean average.

Including your Bf-109F....

So some Bf-109E's were just as fast as some Bf-109F's. On average though, the Bf-109F series was the faster airplane.

Understand?

Can you please convert 990 mmHg to ata for us please :grin:

You don't have to explain it to me, it is in black and white what Mtt says.

Being an experienced pilot, multiple aircraft owner, and having graduated college with a degree in Aeronautical Science, I can decide for myself what is optimistic and what is not.

Thanks! I don't feel the need to convince you one way or the other about it either. You can also decide for yourself. :) I would suggest using some scientific method or at least aviation industry standards when doing it.

About 1.28 ata....

Are we still talking about horizontal flight? :grin:

So you asked me about my background so you can share yours? You're a very nice person Crumpp, it's a pleasure talking to you. :)

So it probably won't be atmostperic pressure at 0m then but rather MFP. :grin:

Exactly my brother....

That French data does not appear to have been converted to standard conditions. They list the conditions though it won't be hard to convert. If someone else does not get around to it, I will do it later when I get home for you guys.

So 41Sqn_Stormcrow was not confusing MFP for atmospheric pressure as you suggested and he was basically right?

No he is not confused but he did stumble on the issue of the atmospheric conditions.

That data was taken on a colder than standard day. Breaking that down, the level speeds will be slower than standard and the climb rate will be higher than standard.

990 mmHg mainfold preassure is 1.34 Ata

and

500 km/h at sea level for 109 E-3 is the best score i have seen in data (German manual). Others are less optimistic.

Strange, such a nice guy, experienced pilot, multiple aircraft owner who graduated college with a degree in Aeronautical Science said that was atmospheric pressure at 0m. :o

Uh, I don't think that's what he said.

Pression d'admission is french for manifold pressure and it's this value that is 990 torr at sea level, not atmospheric pressure (760 torr). The 109 is supercharged, so the pressure in the intake manifold is delivered above atmospheric.

When i read the tenor of some the posts here, i really wonder if there would be the same energy afforded to downgrade the vmax. of the Spit Ia.

People get emotionally invested in their favourite plane and/or its traditional adversaries.

Facts vs facts would be much easier, opinion vs fact or vice versa is a neverending story. :D

I know a bit French and atmospheric pressure is pression atmosphèrique (et non pression d'admission comme on peut lire en bas d'echelle) - even for engineers. Perhaps with some poetic freedom they would have written pression ambiante. It is however written pression d'admission and this is a technical term. I checked and the most suitable translation are inlet pressure or manifold pressure.

See translation here:
http://dictionary.reverso.net/french...'admission.

I have no clue what exactly they address here as pression d'admission and of course this is open to debate. I am however quite sure that they don't mean atmospheric pressure. Perhaps a Frenchman could tell if one is around?

EDIT: My calculator sais that 980 mmHg = 1.289 atm (=ata?)
and 990mmHg are 1.303 atm

So basically the French achieved 494 kph at 600 m with rpm 2400 and 1.303 atm pression d'admission
Extrapolating pessimistically to 0m they got 478 kph with rpm 2400 and 1.289 atm pression d'admission

Je ne suis pas "Francais" mais bien sur je suis Canadien. "Pression d'admission" veut dire "Manifold Pressure". Il ne fait aucun doute.

Pour "atmospheric pressure" je dirais "pression atmospherique".

Yep. 990 mmHg (torr) is equal to ~1.32 bar or ~1.303 atmospheres (ATA on the German gauges).

Yep, I read the doc and converted 980mm. Later I confused it with the 990mm he was asking about.

Of course. Who cares about opinions? I have one, you have one, and everyone knows what they are like....

Facts are the engineer firm of Mtt entered into a contract to deliver the stated performance. The customer (RLM) held that firm accountable and tested each airframe delivered to ensure it met the contractual agreements in place.

Works the exact same way in today's aviation marketplace!! :)

"Intake pressure".

1 ata is a technical atmospheres (at = technical atmosphere, a = absolut) and 1 at equals 735mm HG. Which makes 990mm 1.35 ata.

1 atm is a physical atmosphere and 1 atm equals 760 mm HG.

Some experts can't tell the two apart and come up with 1.28 ata for 980mm, which is wrong.

Regarding the 1792 serial number Bf 109E-3 trials you posted, note the following note by the tests makers at the bottom for 467 km/h:

"These speeds has been corrected for normal (standard) temperature, and correct manifold pressure regulator settings (I guess that is the German way of saying: nominal boost) but not for the guaranteed (ie. nominal) output of the engine."

In other words, this test is for unknown power from the engine. All engines vary in output, sometimes quite considerably, and this would effect results. I would hazard to guess that the airframe may have been a poor one (remember: 500 km/h means anywhere between 475 and 525 is okay for service acceptance), and the airframe may have been a bit down on power.

Here's for example another Emil tests, showing the performance with the engine slightly down on power (developing 45 horsepower less than it should, lower figures) and corrected to nominal engine output (higher figures). This is actually the only test I've seen where anybody measured the used engine's output on a engine test bench.

With the sligthly down-on-power state for the DB 601Aa engine we have in the sim, this Bf 109E (V15a prototype actually, but its identical to the serial E-1 model), radiator 1/4 open, they got 493 km/h at 0m, and correcting the figure for the nominal full power output, 498 km/h.

http://www.kurfurst.org/Performance_...15a_blatt6.jpg

Also 1.3ata is for the 601A-1 engine, the 500 km/h speed is understood for the slightly more potent 601Aa (though I do not believe, based on tests, that the difference would be greater than 10 kph at low level). So for an airframe just hitting the 475 km/h bottom of the acceptance limit, and having the bit less powerful 601A 467 km/h seems quite understandable.

Note though - COD seems to have choosen to model the DB 601Aa version for the Emil.

However this would represent a sub-standard aircraft. There were such, of course, but it begs the question, why would the premiere LW fighter aircraft of 1940 would be represented as a sub-par example, while RAF fighters using the performance of avarage good planes....?

Especially as the new COD engine is capable of simulating wear and such.

I don't think so, the French trials of 1304 confirmed the 570 km/h top speed (and I believe it wasn't even full 1.3ata at altitude), and it is known for certain that 1304 had the old type supercharger.

No kidding!!!:)

If the speeds for Steig/Kampfleistung (1.23ata) are not met by the game 109 then there is certainly a problem with the speed of the game 109. Speeds should be check for Start/Notleistung (1.30ata) as well.

The Bf109E-1, -3, -4 with DB601A engines DID NOT use C3 fuel. They used B4 fuel. Only 109Es with the DB601N engine used C3 fuel. C3 fuel was scarce, unlike British 100 octane fuel, and was only at certain bases. The DB601N engine was not that reliable as was the quality of the c3 fuel.

Oliver Lefevre (109 guru):

"The Speed curve which appear in the Export manual" (Yugoslavia) "seems to have been made up... Keep in mind that it was an Mtt manual not an RLM one and that it was for export."

On 1.4 ata usage

"The technical documentation is quite clear that it should not be used at high altitude, that it put some extra strain on the engine and that only in cases were take-off run was an issue should it be used. This was primarily designed for fighter/bombers and bombers carrying heavier load on take-off, keep in mind that the 109 was not the only a/c relying on the 601."

On Bf109E production numbers

"Here is the data i have based on production blocks, there is probably some innacuracy in the E-7 / E-7/N and E-7/Z department...

E-1 = 1086
E-1/B = 107
E-3 = 1406
E-4 = 250
E-4/N = 20
E-4/B = 212
E-4/BN = 15
E-5 = 29
E-6/N = 9
E-7 = 419
E-7/N = 3
E-7/Z = 17
E-8 = 60
Total = 3633"

The Russian testing was with a DB601Aa engine powered Bf109E.

Quick ballpark of the data to standard conditions….

478 kph TAS x 0.539956803 nautical miles at +5C = 258KTAS

We don't have a piece of the puzzle which is the atmospheric pressure for that day. I am not looking for it but if somebody finds it, I will refine the calculation.

258KTAS x 1.0299 SMOE for our density altitude Temperature difference = 265 KTAS

265KTAS / 0.539956803 = 492kph

492 kph is within 1% of Mtt stated mean of 500kph over a range of 5%.

If we had the pressure and I wasn't using some quick rules of thumb of a standard atmosphere chart but did the full calcs, I bet it would give even better agreement. The French might have had an optimistic performing Bf-109!!

The French test results give very good agreement with Mtt's published figures for the type.

Well please, read the French report and enlighten us as to what units the French are using for pressure....

If you are as smart as you think then Google French units of measure.

While the French did use metric, they had their own unique system.

http://en.wikipedia.org/wiki/Units_o...ment_in_France

I don't know what they used but it is not the German Technical Atmosphere and the test was not flown at a 5 minute rating for the duration.

Pffft.....back to ignoring you until you have something to contribute.

His reply was on a bad tone but he might be right with respect of atm being not equal to ata. I myself was not sure if atm = ata that's why I used atm for my calculation.

Unfortunately there is little information about the outdated ata but 1 at (technichal atmosphere = pressure produced by a column of 10m water) is equivalent to 735.56 torr (almost identical to 735.56 mmHg). ata is with a reference point of 0 (I assume 0m that is sea level), so this would be the pressure produced by a 10m column of water at sea level. That's what wiki told me.

I am quite sure they used the ata gauge in the plane to measure it and then translated it into mmHg.

There is one minor uncertainty with respect to the French measurement of the manifold pressure however. The mmHg values depend on the knowledge of the density of mercury. This knowledge may have evolved since ww2 so there is a slim risk that they used a different mercury density for their mmHg units. However I think there is quite a weak chance that knowledge on density of mercury evolved so much that the mmHg values would be impacted by this to the precision that is of interest here.

So basically the French obtained 494 kph at 600m with 2400 rpm and 1.346 ata.
Extrapolating pessimistically to 0m they would have obtained 478 kph at 0m with 2400 rpm and 1.332 ata.

The ingame performances are still enormously off these values.

Where do get that? The French NEVER used the German technical atmosphere.

The French were instrumental in forming the ICAO in 1912 and adopting a standard atmospheric model of that organization, the ISA.

The ISA uses 760mm as 1 ATA.

Once more, the 1.28 corresponds to the 1.3 ata rating. There is NO 1.35ata rating cleared for the DB601A according to any documentation I have seen.

I suggest looking at this link for Pressure units http://en.wikipedia.org/wiki/Atmosphere_%28unit%29

READ the report!! (You are not the only one either, I did not pay attention to some details either)

The limitations of their own instrument measurements:

The data is not converted standard conditions.

If you do convert it to standard conditions then the French conclusion is correct:

http://kurfurst.org/Performance_test...formanceT.html

Crumpp calm down dude :o

http://en.wikipedia.org/wiki/Interna...n_Organization

http://en.wikipedia.org/wiki/Interna...ard_Atmosphere

p0 sea level standard atmospheric pressure 101325 Pa = 760mmHg....

There is nothing that says WHAT the French used on that report so this whole line of discussion is a complete sidetrack.

I am calm. I just think it is very funny that in all these discussions, the documentation gets ignored by so many and speculated upon so much.

It is what it is and the answers are written in black and white.

There is no need to guess or offer opinions. The report flatly states the data is raw and not converted to standard conditions.

It was flown at a 5 minute rating. We can speculate until the cows come home about which of the 5 minute ratings were used.

980mmHg/760mmHg = 1.289 or 1.3 ata or 1% error

990mmHg/735mmHg = 1.346 ata or 1.35ata or 1% error

It does not matter because in the end, nobody knows for sure.

It is a fact, if you convert the French data to standard conditions, it very much agrees with Mtt's published mean performance of 500kph at 0 meters with a -/+ 5% range.

I dunno but you sound a bit excited.

No it doesn't but it does give info on conversions.:)

ata = at
1 atm = 1,0332 ata

By all means point that out.....


http://kurfurst.org/Performance_test...formanceT.html

Unless the French installed there own manifold boost pressure instrument in the 109, the boost pressure used would be conversions of the German manifold boost instrument installed in all 109s, ie ata to mmHg.

http://kurfurst.org/Performance_test...formanceT.html

They certainly could have used their own measurements. We don't know enough to determine it and any other conclusion is just a guess.

Well, we might not know but we can take the most probable assumption. The chances that they would be wrong would be accordingly small.

Unless some specific clues indicating that the French were using a different transversion from ata to mmHg exist the most probable assumption would be that they used the same.

Maybe they were not using ata at all. We don't know.

What instruments did they use? They only had a 3% instrument error which is very good.

Most bourdon tube or bellows instruments found in the panel are ~5%.

What is a fact is that the data is not converted to standard conditions.

Do we know if the E-4 modelled in game has got (or is supposed to have) a DB 601 Aa engine?

The 'French test' is very interesting, but as Crumpp says, somewhat difficult to use for modelling a E-3 for the sim. The instruments are not the biggest problem really - we can still convert it back, we can also convert the whole test to 'standard day'. The issue seems to be the shape of the plane and components replaced / used, oil, glycol etc... The French apparently had a German manual to compare the outcomes with, and although the top speed was matching, there were some problems with overheating and even engine malfunction (not specified though) resulting poor climb rates when compared to the manual. It took them almost 2 minutes longer to climb to 6000m, that's a massive difference. The 50km/h difference Kwiatek pointed out might also have something to do with the overheating problems - rads were really draggy, but the 50km/h difference between fully open and fully close is rather surprising. Mind you that the difference with and without 500kg bomb was exactly the same at comparable power for a E-4/B (E-3/B), see here

Regarding the differnce between 'guaranteed' and real perofmance:

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

I know that's the V15a, but you get the idea why I think it would be generally unwise to modell the E-4 for CLoD after manufacturer's promises.

It's not a promise it's a contract. I.e. if the aircraft doesn't meet the specifications laid out in the contract then the RLM does not accept the aircraft and it goes back to the factory.

I thought this would be a pretty straight forward idea?

It is pretty straight forward indeed:

The contract says (regarding the top speed at the deck) 500 km/h + - 5%. Which means 475 - 525km/h. (Aa on EN ('1)) No one is saying that the manufacturer was not meeting these specifications, all I was trying to suggest was that the actual Emils were very likely to be in the 485-495 range as the real life tests + conversions suggest. Not all new machines have been test-benched and the brand new engines are unlikely to be pushed to the limits.

Is the E-4 in CLoD really (confirmed) a Aa version? Do we know what fuel we've got? Do we have any variations in FM regarding wear and tear? That would be great actualy.

Regarding V15a performance in these test it didnt have variable-speed hydraulic supercharger control and of course it was a prototype plane ( in most cases prototypes reach better performacne then serial production planes)

Later test - French and Swiss show that tested planes had variable-speed hydraulic supercharger control with smooth speed curve but using variable hydraulic supercharger could casue some lost in speed at sea level but other hand cause more smooth speed range depend of alt without lost power between 2 speed supercharger.

So i think V15a test and performance could not be accurate for performacne of standart 109 E planes with variable speed supercharger.

Also Swiss 109 E-3 test is very accurate with German results at 1.3 Ata power at sea level speed.

http://kurfurst.org/Performance_test...MP16feb39.html

http://kurfurst.org/Performance_test...-347_speed.jpg

Swiss 109 E-3 reached 464 km/h with original prop ( 5 minut power) and from German test we got 467 km/h at 1.3 Ata 2400 RPM.

Crumpp your calculation of 492 km/h is spot on, nice one!

Regarding the French test - it seems they had a sub-performing 109 and / or some problems with the components and fuel, olil, etc. Although the top speed figures are within limits, what do you think about the radiator drag and overall climb performance (see my previous post?) Hard to explain...

Some time ago i made speed comparison between RL Spit MK1 +6/+12lbs (blue/red line), Hurricane MK1 +12lbs (green line) and 109 E-3 Db601Aa (black line, data from german manual 0-500 km/h , 5 - 570 km/h).

http://i56.tinypic.com/9qcrvb.jpg

Nice job Kwiatek, just to remind you that the V15a was identical to series E-1 and it has had some problems to reach the guaranteed power output and the difference in PS had to be calculated, hence the staggered line. In this case the prototype certainly performed worse... As for the supercharger, that's just as you wrote, the V15a had the same supercharger also, but the test was commited without it on purpose (as per the test description).

The French test was very accurate as for the top speed, also in the same ballpark. That's for the E-3 with 601A and 9-11081A, at 1.3 ata, 0m. What was the rad setting? Also 1/4 open?

it was not "variable" compressor. It was a step frwrd in that direction. For what I know Germans never reached tht stat of the art for multiple raisons.

As it was alrdy discussed, the French test used a damaged aircraft with cooling problem. I hve in memory that oil compatibility was also an issue (remind that those engine at the time used a lot of oil per flight hour).

The Swiss 109 were also slightly modified 109E.

It would be better guys to source the E perfs from German doc and actual flying warbird.

I remember reading the flight test of the first E3 flying in US with a 450 sea level speed at 1.2 (or was it 1.3 ?)

What ever is the right case my opinion is that you guys are wrong to try to build a super E to match the hollystic (a contracted word made out of Hollywood and mysticism ? :rolleyes:) Spit we hve in game.

I know that most of you prefer late war super banger. But BoB is all abt early war plane. So pls be patient ;)

By the way I still hve no prob to dash at 500 deck in my 109. SO I don't see what is all abt in this chating.

@Kwia : As I alrdy said those last curves you posted are complete phantasmagoria. Just look at the poor Hurri reaching it's VNE btw 7.5 to 19kft. May I suggest you to throw that one away ?

Dennis the Menace
 

Robo, change your name to Dennis the Menace and stop picking on Crumpp.
Crumpp, give up, mate, obstinance trumps knowledge every time!;);)

Quite OT dude :o I happen to agree with Crumpp in almost all of the things he wrote, I dared to comment his attitude and pointed out that everybody is making mistakes. Nothing to do with you, Sir. ;)

TomcatViP - no, we're not trying to build an Emil that was better than the real thing. I see that many opinions and fact inetrpretations here are on the optimistic side, but as whole, we discuss this matter because we find it interesting. We don't even know it that affects anything regarding the FM. Most likely not.

French test - completely agree, but Swiss top speed was prior to the modification and seems to be legit (and interesting).

I wonder how supercharger control - variable hydraulic speed or 2 postion could affect on performacne. Surly speed curve for hydraulic is smooth without power lost between gears but other hand it could casue some lost.

In V15a chart black thick line speed was made at 1.31 Ata power output - it reached 485 km/h with radiator 1/4 open. Still we need to remember that these is prototype NOT A SERIAL PLANE with different supercharger control.

Later German test show that standart 109 E-3 with Db601A at 1.3 Ata 2400 RPM reached 467 km/h at deck with also 1/4 radiator open.

http://kurfurst.org/Performance_test...MP16feb39.html

So i think speed for 109 E-3 with 1-minute emergency power depend of radiator settings ( 1/4 open or close) and type of engine Db601 A or DB601Aa was in range 485-500 km/h.

TomcatVIP for Hurricane MK1 i found 2 charts:

http://www.wwiiaircraftperformance.o...ne-I-level.jpg

http://www.wwiiaircraftperformance.o...peed-HRuch.png

The second at 12 lbs line looks more reliable to me also.

That's not what I wrote ;). I said the V15a's engine was lacking 45PS (nothing to do with the supercharger) and the actual curve had to be calculated for guaranteed engine output. A different supercharger control would only make a difference between 2200 and 4800m, not down on the deck. The only problems mentioned (except major issue with the engine performance) was lack of manifold exhaust covers and rough finish of the engine cover.

And I agree. The Aa should behave slightly different down low and the EN rating was different, too. That's why I am asking if we really have (or suppose to have) a Aa 601 or A version.

Can you guys put a chart together with exact information (all rated ata settings, rpm, rad setting...) for both DB 601A and DB 601Aa with aproximate guestimated max TAS at the sea level?

http://kurfurst.org/Engine/DB60x/datasheets/601a1.jpg

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