Experimental Results of Winglets on First, Second, and Third Generation Jet Transports

Results of wind tunnel investigations of four jet transport configurations representing both narrow and wide-body configurations and also a future advanced aerodynamic configuration are presented including performance and wing root bending moment data. The effects of winglets on the aerodynamic characteristics throughout the flight envelope were studied. The results indicate that winglets improved the cruise lift to drag ratio between 4 and 8 percent, depending on the transport configuration. The data also indicate that ratios of relative aerodynamic gain to relative structural weight penalty for winglets are 1.5 to 2.5 times those for wing-tip extensions. Over the complete range of flight conditions, winglets produce no adverse effects on buffet onset, lateral-directional stability, and aileron control effectiveness.