If business aviation has been in a spin, the latest numbers from research firm ARG/US show we've likely reduced power and applied opposite rudder. Flight activity in April for that segment of general aviation did decline a whopping 18.8 percent compared with the same month in 2008, but was down only 1.86 percent from March. Traditionally, April is a much slower month than March, with typical statistics showing drops of 5.07 percent (for 2007) and 10.78 percent last year. ARG/US TraqPak data, which uses serial-number-specific IFR arrival and departure statistics as a base, shows Part 135 activity plummeted 45.6 percent this April compared to April '08. Fractionals followed at 26.4 percent, with Part 91 declining by 2.4 percent. The numbers support the theory that on-demand charter is the first segment to suffer in an economic decline. The ARG/US report revealed that Q1 activity this year fell by more than 31 percent compared with last year's stats.