109 e4 performance

[Kwiatek]

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

[Crumpp]

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)

+/- 5%.....

[Robo.]

Originally Posted by Crumpp

+/- 5%.....

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?

[Kwiatek]

Originally Posted by Robo.

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.

[Robo.]

Originally Posted by Kwiatek

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.

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.

[Crumpp]

Extrapolating it would be at 990 mmHg at 0m.

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.

The results obtained in the Center during the first tests seem to
match well with the German manual, with regards to the level flight
speeds and the fuel consumption. Nevertheless, during the level flight
testing done under 5000 meters (external temperature = +6°C on ground
and -17°C at 5000 m.)

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.

[Crumpp]

Do you think there was a Bf 109E-4 able to fly 525 km/h under citied circumstances?

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?

[Crumpp]

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

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.

[Crumpp]

Can you please convert 990 mmHg to ata for us please

About 1.28 ata....