Wind tunnel drive fans

NFAC 80-foot-by-120-foot wind tunnel drive fans. After re-powering the facility in 1980 and increasing the capacity of the wind-generating turbines, the smaller section's top wind speed was increased to 300 knots (345 mph) while the large section, which is big enough to test a Boeing 737, is capable of a top speed of 100 knots (115 mph).

The tunnel has six 40-foot diameter fans each with 15 laminated wooden blades. When operating at full power the fans turn 180 revolutions per minute, moving 60 tons of air per second, using 104 megawatts of electricity -- the equivalent of a 225,000-person city, NASA says.