The Air Zero-g aircraft is the world's largest used for parabolic flights whereby the passengers and experiments are treated to a rollercoaster ride, flying angled at 49 degrees 30 times per flight.
Parabolic flights are used to conduct short-term scientific and technological investigations in microgravity and reduced gravity, to test instrumentation before use in space, to validate operational and experimental procedures, and to train astronauts for spaceflight.
The flights are managed by Novespace, a subsidiary of CNES. ESA typically conducts two parabolic campaigns a year. Scientists are invited to submit experiment proposals for review and selection.