I am a US green card holder. I am traveling from Ouagadougou (Burkina Faso) to New York. The airline is Brussels airline and from Brussel we need to tranfer to another plane that will take us from Brussels to Geneva, there we can go to New York. I would like to know if I need a Schengen airport transit visa for the Brussels-Geneva leg.
Brussels and Geneva are both in the Schengen area. For this reason, the flight to Geneva will depart from another part of the airport than the flight from Ouagadougou and there will generally be no passport check on arrival in Geneva.
Because of that, an airport transit visa is not enough and the US green card does not help either. You will enter the Schengen area in Brussels and leave it in Geneva, with a passport check and stamp in each case and for that you need a regular Schengen visa (if you are a citizen of Burkina Faso).