Boeing's 787 family has larger windows so more people can see out. They change from transparent to opaque electronically. At left is completely opaque, at center is transparent, and at right is an intermediate setting.
The Boeing 787-9 test aircraft has massive water tanks. Up to 7,000 pounds of water can be shifted around to test different weight distribution situations.
Boeing saved weight on the 787 family with these remote power distribution units (RPDUs). Instead of many running power cables from a central electronics bay, these supply power closer to equipment that needs it, meaning less heavy copper wiring.
The back of the first 787-9 has coiled tubing extended from the back of the plane's tail during test flights. It's used to measure the true air pressure to compare with the different higher and lower pressures near the plane.
