1 is shown airflow is shown by the arrows f diverting vanes 200 201 202 203 each change the airflow direction by 90 degrees two fans 40 41 are schematically shown mounted horizontally side by side in their housing 3 refer to fig1 for a perspective view wherein right after the fans a plenum diffuser 300 expands and slows the airflow the diffusing continues in top plenum 30 and then in vertical return plenum 5 and finally through the flight chamber 10 a passive temperature regulation system is provided by having air inlet 12 louver 120 face downstream additionally the air outlet 26 has a louver 260 that faces upstream by mounting the inlet 12 about opposite outlet 26 a reducing nozzle is formed by louvers 120 260 thereby creating a decreased static pressure zone v downstream from the inlet 12 therefore ambient air is forced passively drawn into the simulator 1 without the use of an additional fan referring next to fig3 the diffuser flight chamber 10 is in the shape of a polygon octagon as seen by the base b base b is covered by a safety net the walls 20 21 22 etc diverge at an optimal aerodynamic angle in the range of about 7 u2013 12 degrees from each other the top of the flight chamber 10 is seen as a rectangle at arrow 110 all or some of the walls 20 21 22 etc may be transparent referring next to fig4 an airflow contractor 400 has the preferred design of a rectangular inlet 401 and an oval outlet 402 transition walls 403 contract the airflow from the inlet 401 to the outlet 402 preferably.