At the Dubai Airshow, Boeing welcomed visitors inside the 777-9, one of four test aircraft in the 777X program to certify the widebody, long-haul airliner in 2025. The aircraft is packed with test equipment to record huge volumes of flight data as pilots put it through its paces. With new GE9X engines and folding wingtips, the 777X program is greatly expanding the big twin family’s capability and efficiency.