KC-10 Extender. You can see the refueling boom. The KC-10 was based on the DC-10 jumbo jet. They were just coming into service when I left the Air Force. It was quite a different experience refueling from a KC-10 than from a KC-135, which was based on a Boeing 707 airframe. The 135 would bounce around a lot during refueling, requiring constant corrections to keep the fuel boom connected. By contrast, the KC-10 was like a big rock in the sky. It didn't bounce around at all. Approaching to refuel was like coming to close to a huge celestial body. It filled up your canopy.