GerryShaw

Hi the reason the props rotate in opposite directions is quite simple; basically if all four props rotate the same way this makes the plane want to turn off in the opposite direction, a stability problem particularly if you have huge great engines like the A400M. Note that the only bigger turboprop engine ever is the Kuznetsov unit fitted to the Tu-95 Bear and some other less well known aircraft. These are fitted with a pair of contra-rotating props for the same reason. So Airbus opted for \"down between the engines\", with the inboard on each wing rotating clockwise and the outboard in the other direction. Someone was castigating the French for doing this under the assumption that there would have to be two types of engines, a clockwise and an counterclockwise variant, which would bring logistic and manufacturing problems. However the Frenchies (and Brits and Germans and Spanish and Italians in Airbus) thought of that, there is only one type of engine which rotates the prop in different directions depending on how it is geared. Yrs GerryShaw