Despite its ambitious aims, Amber, like Albatross, was largely home-made by Mr Karem’s small team. It was powered by a four-stroke petrol engine developed secretly in the garage of Hans Hermann, a Formula 1 racing legend of the 1950s. Its cutting-edge electronics and remote-control ground station were assembled in the living room of another employee. “When I started, people asked why I was making a UAV with four times the computational power of the F-16, the first fly-by-wire jet fighter,” says Mr Karem. The reason was that, as any computer buyer knows, a more powerful machine takes longer to become obsolete. “Almost all of our subsystems from 1985-89 are still flying in some Predators today,” says Mr Karem, “including its 27-year-old computer and, with minor changes, the ground station.