May day, somebody help me please!!!

[VO101_Tom]

Originally Posted by Blackdog_kt

From whatever kind of testing i've done, it seems to me that it's not a fuel primer pump that is used for starting the engine, but an emergency pump used to lower flaps/gear when things like hydraulics fail. For example, to lower gear in the 109 after a failure, first you enable the emergency gear mechanism (there's a separate lever for that and also a keybinding if you want to assign a key to it), then you set the gear lever to lower gear (just like you would do for normal extension) and finally, you start clicking on the pump or pressing the key you've mapped to it.

Hi.
Excellent summary, but I would have a question. Were is the hidraulic emegrency pump in 109? I know only the fuel pump... i dont think, that the hidraulic and fuel system used same lever...

Originally Posted by Blackdog_kt

For example, the 109 had an inertial starter but batteries were heavy back then, so they didn't install a battery powerful enough to sufficiently spin up the starter in order to save weight. It was actually the mechanics/ground crew that did it manually with a hand-operated crank, then the pilot engaged the clutch that coupled the spinning flywheel to the engine drive and the engine would turn and start.
If you've ever seen wartime films of luftwaffe personnel in black uniforms running to a line of 109s, inserting a hand-crank into the cowling and turning it like mad, this is exactly what they did.
...
In other words, the "I" key represents engaging the starter but since there were so many different kinds of them and many required even more separate steps and possibly coordination with the ground crew, you won't find the equivalent of an "I" key in the cockpit.

This is true partly only. The 109 ignition switch is there, where it is on the drawing. But you are right, a couple of steps are missing yet for the starting procedures (electric system switch, fuel pressure, oil pressure, flywheel, etc).