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Plelv44_Mangrov
01-08-2008, 11:03 AM
Few extracts from a study made by cadet Esa Tervonen on 19th May 1952, two years the Bf-109s were removed from Finnish service. Probably nothing new to some, but still nice to see something Finnish besides from the MT-215 test report. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif


MT:n nousu 5000 m:iin tapahtuu nopeesti johtuen koneen suuritehoisesta korkeusahtimella varustetusta moottorista. Nousu nopeudella 270 km/t on nousuaika vain n. 5 min 15 sek.

"The MT (Finnish designation for Bf-109) climbs quickly to 5000 meters due of the powerful supercharger installed to engine. Climbing with speed of 270 km/h it takes only around 5 minutes 15 seconds from 0 to 5000 m."


Maksimiteho koneella on siell� 1355 hv, suurin kestoteho on kuitenkin 1080 hv. N�ist� luvuista huomaamme, ett� MT:ll� on 5000 m:ss� parhaimmat lento-ominaisuutensa aina 5700 m:iin saakka. Vasta siit� yl�sp�in ment�ess� teho alkaa laskea.
K�yt�nn�ss� MT:n lento-ominaisuudet 5000 m:ss� ovat hieman erillaiset kuin matalalennolla lennett�ess�. Kone on herkempi, taipuisampi ja helpompi ohjata kaarroissa.

"The maximum power gives out around 1355 HP, the max. continuous power is 1080 HP. From the figures one can figure out that MT has the best flying characteristics from 5000 to 5700 meters. Only higher than that the engine startes loosing power.
In practice the flying characteristics of MT are different in 5000 meters than in surface. The plane is more sensitive, flexible and easier to control in turns."


Nousua jyrk�ss� kaarrossa on syyt� varoa, ettei koneen nopeus p��se liian pieneksi, sill� MT:kin voi joutua sy�ksykierteeseen nopeuden pienentyess� alle 250 km/t ja jos silloin ohjataan virheellisesti. Sy�ksykierteess� on huomioitava, ett� kone putoaa n. 1 km yhden kierteen aikana.

"Climbing in steep turns is to be avoided since if the speed is decreased below 250 km/h and if the aeroplane is not flown correctly the plane could enter in spin. The plane lose altitude around a kilometer per spin."

Plelv44_Mangrov
01-08-2008, 11:03 AM
Few extracts from a study made by cadet Esa Tervonen on 19th May 1952, two years the Bf-109s were removed from Finnish service. Probably nothing new to some, but still nice to see something Finnish besides from the MT-215 test report. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">MT:n nousu 5000 m:iin tapahtuu nopeesti johtuen koneen suuritehoisesta korkeusahtimella varustetusta moottorista. Nousu nopeudella 270 km/t on nousuaika vain n. 5 min 15 sek. </div></BLOCKQUOTE>

"The MT (Finnish designation for Bf-109) climbs quickly to 5000 meters due of the powerful supercharger installed to engine. Climbing with speed of 270 km/h it takes only around 5 minutes 15 seconds from 0 to 5000 m."

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Maksimiteho koneella on siell� 1355 hv, suurin kestoteho on kuitenkin 1080 hv. N�ist� luvuista huomaamme, ett� MT:ll� on 5000 m:ss� parhaimmat lento-ominaisuutensa aina 5700 m:iin saakka. Vasta siit� yl�sp�in ment�ess� teho alkaa laskea.
K�yt�nn�ss� MT:n lento-ominaisuudet 5000 m:ss� ovat hieman erillaiset kuin matalalennolla lennett�ess�. Kone on herkempi, taipuisampi ja helpompi ohjata kaarroissa. </div></BLOCKQUOTE>

"The maximum power gives out around 1355 HP, the max. continuous power is 1080 HP. From the figures one can figure out that MT has the best flying characteristics from 5000 to 5700 meters. Only higher than that the engine startes loosing power.
In practice the flying characteristics of MT are different in 5000 meters than in surface. The plane is more sensitive, flexible and easier to control in turns."

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Nousua jyrk�ss� kaarrossa on syyt� varoa, ettei koneen nopeus p��se liian pieneksi, sill� MT:kin voi joutua sy�ksykierteeseen nopeuden pienentyess� alle 250 km/t ja jos silloin ohjataan virheellisesti. Sy�ksykierteess� on huomioitava, ett� kone putoaa n. 1 km yhden kierteen aikana. </div></BLOCKQUOTE>

"Climbing in steep turns is to be avoided since if the speed is decreased below 250 km/h and if the aeroplane is not flown correctly the plane could enter in spin. The plane lose altitude around a kilometer per spin."

Kurfurst__
01-08-2008, 01:49 PM
If you can translate the thing into English, I`d be happy to host it on my site, and naturally give you full credit for it.

I believe the Finns did handling trials with MT 215 apart from the performance trials available on my site, yes?

Waldo.Pepper
01-08-2008, 02:20 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">"The MT (Finnish designation for Bf-109) climbs quickly to 5000 meters due of the powerful supercharger installed to engine. Climbing with speed of 270 km/h it takes only around 5 minutes 15 seconds from 0 to 5000 m." </div></BLOCKQUOTE>

Going to have to try and replicate that in game. Thanks.

Plelv44_Mangrov
01-08-2008, 10:27 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Waldo.Pepper:
Going to have to try and replicate that in game. Thanks. </div></BLOCKQUOTE>

Please notice that Finns didn't use maximum power in their "Mersus". MW50 and GM1 were removed and the power setting was limited to setting which, If my memory serves me corretly, is the same as 100% in IL-2.

Waldo.Pepper
01-09-2008, 01:45 AM
Well I ran three tests, which were kind of casual. I was not very anal in my procedures. I left prop and rad in auto. I reckoned that as it was postwar there would be no ammo and full fuel.

First I took a G2 in the postwar colours of MT-215 to 5000m.

If I count only that time since the wheels left the ground I got her to 5000m in 4.2 minutes.(282 seconds) If I add in since start of wheel roll add 58 seconds. (I could have gotten off the ground faster than 58 seconds but I was enjoying the ride.)

So next I repeated it with a unarmed G6. I did go to 110% for the second test. From wheels off to 5000m the time was identical. I didn't roger around and takeoff so slowly this time. So if you include takeoff roll add 40 seconds.

Third time, same plane and conditions but I restricted myself to 100% power. Wheel off was 45 seconds. Air time to 5000m was 5:46 seconds.

So there it is fwiw. Close enough for me, certainly with a $40 game. Made ntrk's and if anyone cares, I shall post them.

Sergio_101
01-09-2008, 02:24 AM
One question beggs.
Did the Finns have 115/145 Av Gas or it's equal?
By that time everyone had access to very high PN fuels.

I think it obvious far higher boost pressures can be
had if running 115/145 instead of the fuels the Germans used, typically under 93 octane.

Sergio

Viper2005_
01-09-2008, 04:44 AM
I don't think it's obvious at all.

High PN fuels give you the opportunity to develop engines to deliver higher specific power.

In the absence of development work they just lead the plugs.

I somehow suspect that there wasn't a lot of DB605 development post 1945...

Indeed, given that spares availability might well have proven questionable (since the OEMs were taken out of the Industry in no uncertain terms in the immediate post-war period), it seems more likely to me that export 109s (and other German types) would have been de-rated wherever possible in order to preserve life until such spares could be sourced, or alternatives (such as re-engineering existing airframes to accept alternative engines) provided.

Plelv44_Mangrov
01-09-2008, 06:22 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Sergio_101:
Did the Finns have 115/145 Av Gas or it's equal?
By that time everyone had access to very high PN fuels.
</div></BLOCKQUOTE>

During the Summer Offensive in 1944 the Germans provided more than enough fuel to the Finns to fight back the Soviets. As the Moscow Armistice banned the use of bombers and limited the size of Finnish Air Force, the Bf-109 was chosed to be the only front-line aircraft in FiAF. The remaining Mersus flew only about 50 hours per year to preserve the fuselages.

It's my understanding that Finnish Messerschmitts used the same German fuel (87 octane) in 1952 as in 1944.

Plelv44_Mangrov
01-10-2008, 10:40 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kurfurst__:
If you can translate the thing into English, I`d be happy to host it on my site, and naturally give you full credit for it.
</div></BLOCKQUOTE>

I have plans to open a page for just these kind of documents. I know Finnish, English, Swedish and German so in time I probably translate the documents for these languages since they are just few pages long.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kurfurst__:
I believe the Finns did handling trials with MT 215 apart from the performance trials available on my site, yes? </div></BLOCKQUOTE>

Probably. Finns probably test flew every plane they had (Though I haven't found any for the captured P-40) and made a report from every flight.

From a document conserning IFR with Messerschmitt.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Tulkoon tss yhteydess mys mainittua, ett MT-koneella on mittarilentotehtvien yhteydess edullista kytt nousussa nopeutta 270 km/t., jolloin variometri osoittaa tavallisesti n. 10 m/sek. nousua. Liu'ssa teline sisll nopeus 270 km/t. ja variometri 8 m/sek. Liuku telineet ulkona ja laskusiivekkeet auki 200 - 210 km/t., ja variometri osoitus 3-4 m/sek. </div></BLOCKQUOTE>

"It's best to use the speed of 270 km/h in climb when flying IFR. The variometer should show around 10 m/s. Diving with gears in, 270 km/t and 8 m/s. Diving with gears and flaps out, 200 - 210 km/h and 3-4 m/s."

Ratsack
01-10-2008, 03:41 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Sergio_101:
...the fuels the Germans used, typically under 93 octane... </div></BLOCKQUOTE>

No, they were not.

The method the Germans used to designate the octane rating of their fuels was different to the method used by the Allies. As the test here points out:

http://www.wwiiaircraftperformance.org/fw190/eb-104.html

the German C3 fuel (96 octane by the German method) was roughly equivalent to 140 grade avgas.

The Me 109 G used B4 fuel, which was nominally 87 octane by the German system. I don't know what that is in normal avgas, but I would bet it's higher than 93.

cheers,
Ratsack

julian265
01-10-2008, 05:47 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Viper2005_:
I don't think it's obvious at all.

High PN fuels give you the opportunity to develop engines to deliver higher specific power. </div></BLOCKQUOTE>

Even on the same engine, you can run with higher boost aka manifold pressure with higher ON fuel.

Higher boost makes detonation more likely, higher octane number makes it less likely.

Plelv44_Mangrov
01-11-2008, 02:05 PM
Bump!

Plelv44_Mangrov
01-12-2008, 11:21 AM
Quite interesting... found some calculations about how long it takes to a squadron of Messerschmitts to take-off and land. For instance it takes 30-40 seconds to start the Bf-109 with two men, 30-38 seconds to taxi 300-500 meters and so on.

Viper2005_
01-12-2008, 01:05 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by julian265:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Viper2005_:
I don't think it's obvious at all.

High PN fuels give you the opportunity to develop engines to deliver higher specific power. </div></BLOCKQUOTE>

Even on the same engine, you can run with higher boost aka manifold pressure with higher ON fuel.
</div></BLOCKQUOTE>

Only at the expense of reduced reliability and reduced life.

In the absence of spares, I would have thought it likely that post-war Bf-109s would have made quite strenuous efforts to conserve engine (and airframe) life.

Plelv44_Mangrov
01-12-2008, 01:31 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Viper2005_:
In the absence of spares, I would have thought it likely that post-war Bf-109s would have made quite strenuous efforts to conserve engine (and airframe) life. </div></BLOCKQUOTE>

Finns did have some spares... spares that were stoled from the Germans just before the Lapland War. Engines and such.

Ratsack
01-12-2008, 04:23 PM
Guys, the premise of the canard about running the engines at higher boosts is false. As I pointed out above, the German octane rating number was not directly comparable to the the Allied numbers. The C3 fuel they were using Fw 190s and MW50 equipped 109s from 1942 was better than Allied 100/130 juice. It was more like 140 or 150. By the German system it was 96 octane.

So I'll say it again for those that may have missed it, the standard German fuels were not 'low PN'. The Fins therefore had no reason to go mucking around experimenting with higher boost pressures because of the post-war availability of 'high PN' fuels. If anything, they may have gone the other way if they couldn't get the synthetic fuels their engines needed.

cheers,
Ratsack