109 e4 performance

[Crumpp]

12/16/39 - Finishing the aicraft setup - roundels painting.

12/18/39 - Instruments inspection by the Center`s pilot.

12/19/39 - Equipment verified during flight.
12/20/39 - (flight interrupted due to fog)

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.

[Crumpp]

different transversion

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.

[Robo.]

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:



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.

[CaptainDoggles]

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?

[Robo.]

Originally Posted by CaptainDoggles

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.

Originally Posted by Robo.

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.

I understand what you want to say and I can partially agree. But only partially. The manufacturer's specification of 500 kmh +/-25kmh does definitely not mean that the 109 reached 500 kmh but probably something less. I however doubt that all 109s will have been on the lower band. This would be basically impossible in terms of production. I also doubt that the manufacturer aimed at achieving 475 kmh, as was suggested earlier by somebody. This would be a dangerous policy for a private company because aiming at 475 kmh (meaning average performance of 475 kmh) would have meant that many many fully assembled planes including engine would have been rejected. Assuming a natural Gaussian distribution of performance this would have equated to a almost 50% rejection. Not one company can afford this. So my guess is that the average in tems of performance will have been well above the 475 kmh. However difficult to tell where it was. Probably somewhere between 475 and 500 kmh and the French test seems to concord with this. Perhaps they did have an optimistic plane. So one might guess that the average would have been at 485 kmh with a dispersion of perhaps 1 sigma = 3 kmh that is with a variation of +/-10 kmh at three sigma. This would make sense from a production point of view to have the lowest performing aircraft of a batch to be at 'average minus 3 sigma'.

[Kwiatek]

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



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.

[Robo.]

Originally Posted by Kwiatek

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)

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).

Originally Posted by Kwiatek

Swiss 109 E-3 reached 464 km/h with original prop and from German test we got 467 km/h.

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?

[TomcatViP]

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 ? ) 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 ?