1 min readAllison Low Speed Noise Fan with Swept / Leaned Stators in 9×15 foot Low Speed Wind TunnelNASADec 10, 2015 Image Article Progress toward quieter aircraft: Allison Low Speed Noise Fan with swept/leaned stators mounted in the 9'x15' Low Speed Wind Tunnel. Progress toward quieter aircraft: Allison Low Speed Noise Fan with swept/leaned stators mounted in the 9’x15′ Low Speed Wind Tunnel.