Kuettner flight-tested the world's largest airplane, the Gigant, during World War II, narrowly escaping death as the plane broke apart in flight and his parachute opened just 200 meters (660 feet) above ground. After the war, I wanted to go to a mountaintop and be alone, Kuettner recalled. He spent three years studying many atmospheric phenomena, including thunderstorm electricity, at the observatory atop the Zugspitze, the highest point in Germany.