Choices of material for the final design

I wanted the vehicle to be built out of aluminium, copper, magnesium and chromium because those are a common type of metals use to made aeroplane as according to my source <http://www.ask.com/question/what-metals-are-aeroplanes-made-from>. 

For the seats, I imagine that the passengers have to take a very long flight as landing and taking off will take a longer time for a vehicle this size. So i picked leather to be the material for their seats so they will have a much comfortable ride. 

The entrance and exit for the plane, I intended to use sliding door as it will not take too much room. Unlike the pivot door.