During parabolic flight manoeuvres, at first, nearly twice the normal force of gravity prevails. After the plane climbs at an angle of 47 degrees, the pilot throttles the engines back and approximately 22 seconds of weightlessness occurs as the plane arcs over into a dive. Once the engines power up, double gravity is experienced once more.
The one or two parabolic flight campaigns conducted annually by DLR have three or four flight days each. About 10 to 20 experiments are carried on board during each 'mission', and up to 35 scientists per flight day.