Coming video for this Friday. (Patreon)

Hi my friends! Another month has gone by and I want to really thank you for your support! You guys are providing an extremely important stable income for me  and my family right now when the airline business has basically stopped providing that.

For this weeks video I want to hear your opinion. I have been promising you the episode about the "tube" for several weeks now so it is likely to be the one but i stumbled over a new question today that triggered my imagination. I was asked why there are so many different units used in aviation which is not used anywhere else, like Feet, nautical miles, knots, Flight levels, hectopasqual etc. 

Which video would you like to see?