We've got to move up to the 21st Century here. So, 40 years ago when Boeing was designing the 747, they rejected the long U/D concept because of the height. No doubt slide development was still in its infancy and they couldn't be trusted. Well here we are 40 years later with (thanks to the 747) many, many years of slide experience and development, and just as the world moved from 707 type areoplanes to 747 cabin levels, and we are flying people around with Upper Deck slides happily, the world will move to really big aeroplanes with Upper Decks and slides to handle them. It's just a question of progress, and it will happen! It's just a question of getting used to it. Airbus has made a pretty good stab at civil airliners- I trust them to have got the design and capabilities right. Why don't we just let them prove they have got it right?