Position issues Wing must stay within 10% of leads wingspan for 30% fuel savings(Proud et al., 1999) Military:C-17:171,C-141:160,C-5:223 Commercial: 747:196.A300: 147 Previous flights 2001: 55(two F/A-18S)(12% savings) 2003:200(DC-8/F/A-18)(29% savings) Pilots most sensitive to changes in roll The most significant vortex disturbance when positioned for maximum drag reduction is a strong rolling moment effect (Hansen et al., 2002) Vortex turbulence generally avoided Step up and down 叫hPosition Issues • Wing must stay within 10% of lead’s wingspan for 30% fuel savings (Proud et al., 1999): – Military: C-17: 171’, C-141: 160’, C-5: 223’ – Commercial: 747: 196’, A300: 147’ • Previous flights – 2001: 55’ (two F/A-18s) (12% savings) – 2003: 200’ (DC-8/F/A-18) (29% savings) • Pilots most sensitive to changes in roll – The most significant vortex disturbance when positioned for maximum drag reduction is a strong rolling moment effect (Hansen et al., 2002) • Vortex turbulence generally avoided – Step up and down