Being curious as to exactly what happens to the props when the Anafi starts, I decided to set up a simulation using a particle based physics engine. The following (in slow motion) shows engine start with the propeller in one of three positions: fully closed against rotation, fully extended and fully closed with rotation:
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The most notable thing is that the propeller will ALWAYS hit the hub of the opposing propeller regardless of the initial start position.
I then tracked the relative forces during collision for each of the start positions:
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The interesting thing here is that starting the Anafi with the props fully extended is possibly the worst scenario.
Folding the propellers fully against the direction of rotation seems to be the safest start up position.
