2 Days until Europe...What am I going to Wear on the Plane?

In two days, I will officially be across the "pond". It has been exhausting trying to fit 26 days worth of clothes in one bag that can not weigh more than 50 pounds. I will be traveling to various countries and cities where the weather varies this time of year. Itinerary: Paris, London, Barcelona, Madrid, Rome and The French Riviera.

My biggest challenge is "What to Wear on the Plane ?". Even though it is a nine hour plane ride... I never know who I may run into, in the airport in Paris that is ; )