109 e4 performance

[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'.

[Bewolf]

Originally Posted by 41Sqn_Stormcrow

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'.

hm, if the manufacturer was able to determin speed output to such a degree that the flight range was between 475 and 500, why then the much larger safety margin up to 525? leftover from times output varied much more?

Perhaps selling issues. Sounds nicer to have a spec at 500 +/-25 kmh than 485 +/-10kmh.

The thing is there seems to be no test on the E series that indicates that there had effectively 109s that reached speeds above 500 kmh.

[Crumpp]

The manufacturer's specification of 500 kmh +/-25kmh does definitely not mean that the 109 reached 500 kmh but probably something less.

It is an average. There is no "probably something less" or "selling issues". No pointy tin-foil required. This is standard stuff in aviation.

The thing is there seems to be no test on the E series that indicates that there had effectively 109s that reached speeds above 500 kmh.

Of course there are flight test's that show that average performance....

Here:

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

[Robo.]

Originally Posted by Crumpp

Of course there are flight test's that show that average performance....

Here:

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

That is the Yugoslavian test we've had here few pages back. There is no mention of the aircraft actualy achieving 500km/h, at least I can not see it anywhere.

[Crumpp]

That is the Yugoslavian test

It is German test but is reprinted in a Yugoslavian report. Of course it is, the Yugoslavian's purchased Bf-109E's...

The Yugoslavian report is used to date the German one.

Reproduction of pages 48 - 53 from Baubeschreibung für das Flugzeugmuster Messerschmitt Me 109 mit DB 601, from circa 1939. The date cannot be positively identified, however, the Yugoslavian translation of the manual, probably shipped along with the Yugoslavian export Bf 109Es, and which is otherwise identical to the German, is dated 1940.

There is no mention of the aircraft actualy achieving 500km/h, at least I can not see it anywhere.

Sure there is:

Die Flugdauer bei Vollgasflug beträgt 1,1 h in 6000 m.
Bei entsprechender Drosselung erhöht sich die Flugzeit bis
auf zwei Stunden.

They flew at full power for 1.1hours, to altitudes of 6000m, and the total flight lasted 2 hours.

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

[Robo.]

41Sqn_Stormcrow - dude you said exactly what I said