U.S. airlines in May experienced a 9.5 percent year-over-year drop in passenger count and a 26 percent decline in revenue

, according to the Air Transport Association. ATA cited the effects of "the H1N1 influenza outbreak," which "compounded an already weak demand situation." UBS analyst Kevin Crissey in a June 23 research note wrote, "Our sources indicate revenue in June, July, and August remains about as bad as in May."