Parabolic flights with the Cessna Citation-II

A typical duration of a parabolic flight is about 1 to 4 hours, according to the user requirements. The home base for the aircraft is Schiphol Airport in Amsterdam, although takeoff and landing could be made from different paces within Europe depending on the user location and experiment requirements.
To create the micro gravity environment, the aircraft follows a trajectory as in the Figure 1, from steady normal horizontal flight, the aircraft pulls up for about 8 sec. The aircraft engines thrust is then strongly reduced to set-in the parabolic free fall. During the free fall period the engines thrust is adjusted to compensate the effect of the air drag making use of the micro gravity flight director. The micro gravity flight director also gives the pilot the required elevator angle in order to maintain the normal acceleration within +/- 0.01 g. After about 15 sec. of micro gravity the aircraft pulls up at about 1.5 to 2.0 g for approximately 12 sec., diving at 50 degrees (pullout) to come back to steady horizontal flight. These maneuvers are flown separated by intervals of minimum 2 minute. Longer intervals between parabolas are possible, giving enough time to change experimental setup, as requested by experimenters prior to the flight.

The number of parabolas flown per flight hour is between 12 and 15, depending on the interval time between parabolas. With the use of the special flight director it is
also possible to fly intermediate g-levels ranging form micro gravity to 1×g.