109 e4 performance

[Crumpp]

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.

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:

Due to that, there is an uncertainity about the results. This uncertainty is about 2 to 3%. Thus maximum speed is 570km/h +/-15km/h.

The data is not converted standard conditions.

Nevertheless, during the level flight testing done under 5000 meters (external temperature = +6°C on ground
and -17°C at 5000 m.)

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

In general, the first tests made at the Center concerning the
Messerschmidt 109 appear to confirm the performances claimed by the
Germans.

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

[Robo.]

Crumpp calm down dude

[Crumpp]

I suggest looking at this link

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.

[Crumpp]

Crumpp calm down dude

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.

[Al Schlageter]

Originally Posted by Crumpp

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

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

[Redroach]

ata = at
1 atm = 1,0332 ata

[Crumpp]

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

By all means point that out.....


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

[Al Schlageter]

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.

[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.