MW 50 tank weight (Bf 109) (2 Viewers)

I don't know how much info on that Handbuch was carried over from earlier operation notes, but some for sure. For example, from Vorläufige Anlagebeschreibung und Bedienanweisung für MW 50-Betrieb in Bf 109 (published by Rechlin E 3 a 1 in spring 44):

Which just points to fill fighters with 85 l and recce machines with 75 l.

For later /R2 variants, a dedicated smaller tank was introduced:

I am referring from another thread on Hyperscale.
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Lynn:

The only version where the MW50 tank could be used as fuel tank was the K4 and that's the reason it was larger (118l versus 70l for the dedicated MW50 tank of the G6/14 versions) and there never was any fuel pump in the wings, the Mw50 tanks were operated on engine pressurised air

On the K4, it is stated that "the tank has a capacity of 118 liters which can be filled with 110 liters of fuel or 75 liters of Mw50 mixture"

The K4 tank was large and fuel was not fed by a pump but by the same system as the drop tank, pressurized air captured from the supercharger

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Not quite.

Aufklärer models were retrofitted with a 70 liter MW 50 tank (smaller, to make room for the camera equipment). This was done at one of three facilities. G-14s and G-10s (and MW 50 equipped G-6s) had a 115 liter tank - the K manual is explicit about a 118 liter tank so I assume there was a slight redesign which gave it a larger capacity. Even so, the maximum amount of MW 50 allowed in that tank was 70 liters (for the 115) or 75 liters (for the 118 liter), as per the manuals... my assumption is that this has something to do with the specific weight of the MW 50 solution vs the weight of fuel, you don't want to have too much weight that far behind the aircraft's CG. (I haven't found anything yet which confirms this, but I do know weight/balance was a concern for the design team)

Lynn
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Vincent Kermorgant:

One thing to remember also is that the K4 was the first where the MW50 could be emptied easily from the cockpit (essential feature when needing to replace the water by fuel or fuel by water)

Funny thing is that I don't know if the tank was ever used to carry fuel in combat

But I still believe that only the 70 liters tank was fitted to the G versions built for MW50. At least the surviving G10 were built with 70 liters tanks, not 115
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Ooh, hang on there - this is a very interesting detail!

All the surviving G-10s are Diana built G-10/U4s (61xxxx). WNF (Diana?) also built the G-10/R2 (77xxxx) recce bird. I know for a fact the smaller tanks were retrofitted during the MW 50 install process on G-8s and G-8/R5s at Wunstorf, Herzogenaurach, and one other place (I have it, just can't remember it). And the smaller 70 liter tank was supposed to be just for the recce birds.

If what you're saying is correct (and why would you make it up, LOL) then that suggests WNF/Diana either never got the big tanks due to supply issues, or ran out and were forced to use the smaller tanks because that's all they had. And I could 100% see that happening... although it looks like Avias wound up with the bigger 115 liter tank, but used just for fuel. Maybe they found a source for them?

Are there pics or docs somewhere which reference the 70 liter tank in those G-10s?

Cheers,

Lynn
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I am going to try to sum up my understanding so far:

1-GM-1 Nitrous Oxide Me-109Gs had a heavy 115 litres insulated tank (which forced the removal of the armour plate) that was converted to MW-50 with added wing pressure bottles preventing the use of 20 mm underwing guns. This was an early to mid 1944 improvisation.

2-A 70 litre MW-50 ONLY tank was used for recon versions like the G-8, but apparently at least one manufacturer, Diana, had it on all the 109s variants it made before the K. (including G-10s) There may have been other makers building Gs with 70 litre tanks (maybe most?), but it is not clear.

3-A 115 litre MW-50 ONLY tank was used on many (most?) pre-K Me-109Gs, but was filled only to about 70-85 litre of MW-50.

4-A 118 litre DUAL USE toggle switch-convertible tank was used only on the Me-109K, but with 110 litres for fuel and only 75 litres for MW-50.

I'll make a quick comparison to the FW-190A based on what I could find:

-The cylindrical 115 litre rear tank was only widely fitted to the later A-8, and was mostly used as a fuel carrier. (It seems only A-9s had MW-50)

"As of August/September 44 A-8s will be delivered with the additional tank. The tank could be used for MW-50, fuel, or GM-1, however currently the plan is only to carry additional fuel..... As of July 44 "sämtliche" A-8s (numerous A-8s) will receive/received the Erhöhte Notleistung (MP increase)." (the MP increase "trick" is described below in another document)

-C-3 air intake injection was used on F and Gs fighter bombers, but this only added power up to 1000 metres. It was not the full fledged boost "trick" below:

-A-8s had higher power at all altitudes through refinements in the engine and throttle: (Manual) : "The increased power is gained by bleeding air from the supercharger....The two nozzles, the first of which has the smaller inside diameter, are so constructed, that when the actuation valve is opened, the air pressure within the boost pressure drops to a very low level; this causes the throttle valve to open wide, thereby increasing the maximum obtainable boost pressure, at 2700 RPM, from 1,42 ata, to 1,58 ata."

The 190A seemed to have been somewhat simpler in that regard...