Feature Request fuel management of Bf110

[ZG15_FALKE]

Being a Zerstörer fanboy I really would like to see fuel management of the 110 implemented correctly.

All informations in this description are based on original documents by Messerschmitt either:
Vorläufige Betriebs- und Rüstanleitung für Bf110 C dated 1.6.39, Reg.Nr. 145
or
Betriebsanleitung BF110C Ausgabe Febr.1940 Reg.Nr.173

The fuel system of the Bf110C consists of four internal self sealing tanks, located within the inner wings.
2 main fuel tanks, capacity of 375 litres, forward of main beam of the wing
2 reserve fuel tanks, capacity of 260 litres, behind the main spar.
Total capacity is 1270 litres
Each tank is fitted with an immersion pump (other configuration with one central transfer pump was only used short time in production for C1 and C2 models and retrofitted in most maintenace overhauls).


The engines are fueled by a pair of engine-driven delivery pumps per engine. Fuel is fed only from the forward main tanks through two fuel lines per engine. These lines are opened or closed by two fuel cocks, operated by levers on the left side of the cockpit. When the lever of corresponding engine is in its rear position marked 'Brandhahn zu' the line of this engine is closed. Is lever in foreward postion marked 'P1+P2' both lines are open. Inbetween these two either P1 or P2 opens only one fuel line for this engine.


The immersion pumps within the main tanks are used for stabilizing fuel pressure in greater altitude or during start run. If fuel pressure drops below 1.1 atü the altitude booster pumps are switched on by operating the switch in the rear to the fuel selector switch to the pilots right.


The fuel lines are vented and primed to their required pressure by pumps operated by reciprocating the hand levers on the control box to the left of the pilot.
If both engine driven fuel pumps of one engine fail it is not possible to feed engine with venting pumps for fuel lines.


The engine cylinders can be primed by a primer pump and a three position switch rechter / linker (left / right engine). Switch in middle position means both primer lines closed. The primer pump unit is to the right of the pilot.


Fuel capacity is shown by a gauge in the middle and to the bottom of the dash bord. The gauge has a double scale calibrated to hundreds of liters. The upper scale refers to the 375 litres main tanks, the lower scale to the 260 litres reserve tanks. By operating the 5-position switch below the gauge of the desired tank can be selected to show capacity on gauge:
0 off, 1 'VL' left main tank, 2 'VR' right main tank,3 'HL' left reserve tank,4 'HR' right reserve tank.


Illuminated red warning lights upper side of gauge are showing rest of approximately 100 litres in left or right main tank, lower warning lights indicate empty reserve tank left or right.


If white warning lamps below turn-and-bank indicator are illuminated main tanks are on capacity below 240 litres.


Fuel in reserve fuel tanks in the rear of the spar is transferred simultaneously from both reserve fuel tanks into one of the main tanks by operating the immersion pumps of the reserve tanks. This is usally done, when main tanks volume drops to about 100 litres. Direction of fuel flow is determined by fuel selector switch. The switch is operated by two levers. One for switching pressure to main fuel tank left or right which is to be filled (front lever). Rear lever operates the immersion pumps, left side 'Ein'. Reserve fuel tank 'empty' is indicated by corresponding warning lights below fuel capacity gauge on the dash bord.

Switching position of selector switch and feeding lines:

The shown selector switch is used in a D Model which has a Dackelbauch ventral tank for maximum cruising range.

C4 and C7 switching logic should be:
°|°
°|° normal switching for use of main tanks, left engines fueled by left main tank and right engines out of right main tank.

°\°
°/° transfer from reserve tanks to left main tank

°/°
°/° transfer from reserve tanks to right main tank

°\°
°|° fueling both engines from left main tank, i.e. if right main tank is damaged

°/°
°|° fueling both engines from right main tank, i.e. if left main tank is damaged


The fuel pressure gauges are combined with the oil pressure gauges and are located on the engine nacelles. The yellow outlined scale is the gauge for fuel pressure. The thresholds are outlined by 'L' marks on the scale.