Author Topic: Climbrate/climbspeed/time to hight??? (Read 1281 times)

elkaskone · « **Reply #15 on:** March 01, 2006, 03:59:03 PM »

Here ist another Russia Document from a Russia Handbook about the BF109E3 with DB601Aa with the same Performance!
I belive that is the same Performance that are on the Messerschmidt Charts, but however i never see the Orginal German Charts!

gripen · « **Reply #16 on:** March 01, 2006, 04:21:00 PM »

Well, the Russian charts for speed seem refer manufacturers claims with 5% tolerance and apparently tested data; there is notable difference but it's unclear if the engine settings are the same (I'm too lazy to try to translate...).

gripen

Knegel · « **Reply #17 on:** March 01, 2006, 06:54:19 PM »

Quote

Originally posted by elkaskone
Look here, at this Documents from DB601A & DB601Aa,
i think these will give you the right anser to your Question!

Hi,

i know the different between the A and Aa regarding the poweroutput, but the discrepancys are very often in the same datasheet and not only related to the Me109!

The answer to my question seems to be: Sometimes there are mistakes included.

btw. why there was a DB601A and a Aa?? What was the technical differents and which engine got used when??

Somewhere i did read the Aa was the export version, but is it possible that the HQ sell the better engine, while the own Luftwaffe get the crap??

Greetings,

gripen · « **Reply #18 on:** March 02, 2006, 02:28:27 AM »

Output at given rating seem to be about the same for both engines. There is some difference in weight and lenght so differences might be somewhere in output gearing (apparently strenghtening) and possibly also in supercharger.

gripen

elkaskone · « **Reply #19 on:** March 02, 2006, 02:30:39 AM »

I have no Documents which I can show you,
but what i have read about the Bf109E makes me that picture:

BF109E1 = DB601A
BF109E3 = DB601Aa (maybe a few early with DB601A)
BF109E4 = DB601Aa
BF109E4B = DB601Aa
BF109E4N = DB601N
BF109E7 = DB601Aa
BF109E7B = DB601Aa
BF109E7Z = DB601N with GM1

I dont think the DB601Aa is the export version, it was the Series engine since the BF109E3!
Focke Wulf has a engine export version for the FW190A3 for the Turks,
it was labelt Fw190Aa3 with BMW801D but slower performance.

The point is, i believe that the 500km/h at sealevel and the 570km/h at 5000m, are manufacturer data from Messerschmidt for the BF109E3 and DB601Aa!
If anybody has orginal German speed charts for the BF109E, please post it will make a smile to my face.

HoHun · « **Reply #20 on:** March 02, 2006, 05:04:31 PM »

Hi Hitech,

>That chart is correct, why you think you know more then the enginers who made the chart?

I'm aware that you are joking, but that chart wasn't made by engineers :-)

The graphical data does not even match the tabulated data.

The speed table shows an anomally high speed at 0 km and a kink in the speed graph between 2 km and 3 km that probably indicates the action of the variable speed supercharger drive.

The climb table shows climb rate fluctuating slightly around a high average below full throttle height, but the climb graph shows the climb rate dropping continously from sea level up.

Regards,

Henning (HoHun)

HoHun · « **Reply #21 on:** March 02, 2006, 05:58:32 PM »

Hi Elkaskone,

>Look here, at this Documents from DB601A & DB601Aa,
i think these will give you the right anser to your Question!

Thanks a lot, I hadn't seen a DB601Aa power graph before! :-)

Based on my above calculation from the Me 109E-1/E-3 Kennblatt, I ran a preliminary analysis using the DB601Aa data from your graph and came up with the following results for 5 min power:

Altitude - Calculated Speed - Tabulated Speed

0000 m - 490 km/h - 500 km/h
1000 m - 514 km/h - 510 km/h
2000 m - 540 km/h - 530 km/h
3000 m - 559 km/h - 540 km/h
4000 m - 577 km/h - 555 km/h
4300 m - 581 km/h
5000 m - 575 km/h - 570 km/h
6000 m - 568 km/h - 565 km/h
7000 m - 559 km/h - 560 km/h

As you can see, the 500 km/h at sea level from the chart don't seem to make sense - maybe that's really the value for 1 min power as it seems too high for 5 min power.

The rest of the tabulated data is slower than it should be, and lacks the relatively low full throttle height with the relatively high top speed evident in my calculation. (No surprise here, the DB601Aa has a low full throttle height, so a top speed achieved at 5 km is obviously unlogical.)

Regards,

Henning (HoHun)

Knegel · « **Reply #22 on:** March 03, 2006, 12:57:25 AM »

Huhun,

as elkaskone wrote, its the 1min speed. Looks like he own more of this datapackage!??

So the Db601Aa was the 'normal' engine in WWII?!

Greetings, Knegel

elkaskone · « **Reply #23 on:** March 03, 2006, 01:45:23 AM »

>Altitude - Calculated Speed - Tabulated Speed

>0000 m - 490 km/h - 500 km/h
>1000 m - 514 km/h - 510 km/h
>2000 m - 540 km/h - 530 km/h
>3000 m - 559 km/h - 540 km/h
>4000 m - 577 km/h - 555 km/h
>4300 m - 581 km/h
>5000 m - 575 km/h - 570 km/h
>6000 m - 568 km/h - 565 km/h
>7000 m - 559 km/h - 560 km/h

Your speed calculation is in the bounds of possibility,
personally i think that the Top-speed (5' rating) between 4000m and 5000m could be nearly the same,
that is which me at the speed diagram also looks a little bit doubtful!

>as elkaskone wrote, its the 1min speed. Looks like he own more of this >datapackage!??

Sorry for the misunderstanding,
it is a pure speculation of me, i forgot the (!?) or (maybe) in my formulation.
But 500km/h at sealevel it a very high speed for BF109E and i dont believe it can be reach at the 5' rating!