Strana 15
HISTORY
weight saving. The injection nozzle was replaced
with a different type, because the pressure from
the compressor was lower. This simplified type
of MW 50 was apparently standard equipment
on the Messerschmitt Bf 109 G-14 and G-10.
A characteristic modification of the design,
visible even to modelers, is the square ‘box’
behind the pilot's head, covering the battery.
In the later development variant of the Bf 109
K, the internal equipment was redesigned
and although the MW 50 was standard, the
aforementioned box behind the pilot's head
disappeared, because the battery was moved to
another place within the fuselage. The MW 50
tank could also be used as an additional fuel tank
in the K version. There was a MW 50/Kraftstoff
switch on the instrument panel and depending
on its setting, the relevant valve switched either
to inject the mixture into the compressor or
to pump the contents into the main fuel tank.
Of course, it was important to pay attention
to the position of the switch depending on the
contents of the tank.
At this point, it is necessary to take a detour
and discuss the Messerschmitt fuel system.
The aircraft were equipped with an L-shaped
fuel tank with a capacity of 400 liters located
under and behind the pilot's seat. The Bf 109 E
version had a sheet metal tank, while a new
special rubberized self-sealing SB Sackbehälter
tank was developed for the F version. This
SB was also developed for C2 fuel used with
the DB 601N engine, but in normal operation,
C3 gasoline was used, which caused unexpected
problems with the DB 601N. Finally, after a long
time, it was discovered that in the rubberized
SB tank, C3 gasoline chemically reacted with
the tank material, which degraded the gasoline
used. Therefore, the SB tank had to be modified
so that this reaction did not occur. Some
Messerschmitt Bf 109s of the F version were still
equipped with the older sheet metal tank on the
production line. The additional three-hundred-
liter droptanks were not equipped with a fuel
pump and compressed air from a compressor
was blown into the auxiliary tank to move fuel
from it into the main tank. When the tank for the
MW 50 was filled with fuel, the valve was set to
pump its contents into the main fuel tank and
the pumping was again done with compressed
air. With the droptanks and the MW 50 filled with
fuel, the Messerschmitt Bf 109 could double
its range. In the Czechoslovak Avia S-199, the
MW 50 tank was used exclusively as a fuel tank.
Notes and clarifications to the November,
2024 article:
- The code word MONA used for the very first
version of the GM-1, refers to, according to
Baumgartl, da Vinci’s Mona Lisa. It would appear
that the model inhaled some nitrous oxide gas,
resulting in her mysterious smile, once and for
all solving an age-old riddle at last!
- I had some reservations about the circular
tank of the GM-1 for the F-4/Z version of the
Bf 109. Baumgartl states that there really was
a GM-1 tank made of thin sheet metal wrapped
with piano wire, but he doubts that it would
have made it into production aircraft. Those
who remember will certainly recall the glass
siphon bottles with metal mesh popular under
socialism, filled with carbon dioxide cartridges
- the principle is the same and the container
withstands internal pressure well.
A little bit of a glossary:
Sonderstoff = A special material (used
specifically with the GM-1 or MW 50 systems)
Kraftstoff = Fuel
Sauerstoff = Oxygen
Behälter = Tank
Leistung = Performance
The wreckage of Bf 109G-10 WNr. 151556 from JG 300 and Bf 109G-14AS WNr. 784998 from IV/JG 53 after
emergency landings in early 1945. Both aircraft show open MW 50 fuel tank filler ports on their spines.
The protrusion on the access hatch to the battery and additional storage
compartment allowed for the former’s relocation forward, which freed up space
for the MW 50 tank in the fuselage behind the cockpit. Bf 109G-14, Oblt. Rolf Schlegel
10./Jagdgeschwader 4, March 1945 [JG 4 Archive - Museum of the Air Battle over
the Ore Mountains on September 11th, 1944 in Kovarska]
Bf 109K fuel system
diagram from
a period manual with
the MW 50 mixture
tank indicated.
INFO Eduard
15
February 2025