So, when I'm creating the Thomas-Morse XP-13 (t to be tagged) the thought of putting engine startup using some funky tree code on the propeller just like in real life comes to my mind.

The question is how do I code for the startup?

The furthest thing I can do is making multiple if logic codes:
(Activate8 ? Throttle : Throttle*0) * (FuelSupply ? Throttle : Throttle*0) * clamp01(PowerSupply ? Throttle, Throttle*0), 1 + clamp(Altitude/100000), 0)

Feel free to criticize the 'test code' that I created

Shikanoin Heizou