1 min readSemi-Span Balance Development and Calibration CapabilitiesNASAApr 27, 2016 Image Article New 30,000 lb normal force (lift) semi-span balance designed by NFMTC for NASA Ames Research Center’s 11-foot transonic wind tunnel facility. New 30,000 lb normal force (lift) semi-span balance designed by NFMTC for NASA Ames Research Center’s 11-foot transonic wind tunnel facility.