Sky Team - are flaps required on the final round?

So my wife and I just started playing Sky Team and aren't sure if the flaps are required on the final round. The instructions don't explicitly say whether it is required for this round but our reasoning is that there are 3 dice for brakes (2,4,6) and it says they have to be used in order. So if the pilot plays a dice for the engine, and all 3 for the brakes, there isn't a die left for the flaps and it doesn't make logical sense that the flaps would be required on the ground. Followup question: if it's not required can one be played to flatten the plane or does the plane need to be flat before advancing to the airport? Thanks!