U.S. government spending on air travel probably fell as much as 30 percent in the past month amid congressionally mandated budget cuts that threaten to keep weighing on the industry, a Wall Street analyst said.Demand for airline tickets from federal employees may stay at this level or even lower "in perpetuity," Jamie Baker of JPMorgan Chase wrote Friday in a note to clients in which he estimated that the government accounts for 3 to 4 percent of airline revenue. He pared his full-year revenue projections by as much as 3 percent.Sequestration's impact on U.S. air travel won't be as bad as the 2008 financial crisis, H1N1 flu, the SARS respiratory outbreak or tsunamis, "but it still stings," Baker wrote. Declining fuel prices may temper the fallout, he said.Savanthi Syth, an analyst with Raymond James Financial, said: "It definitely will put pressure on earnings near-term because business demand is soft. ," said . But capacity control -- the reason that this industry is different than it has been historically and able to create profits -- is still intact. We see sequester as a short-term impact with little visibility as to when it will ease."Delta Air Lines paced a decline by the Bloomberg U.S. Airlines Index, which slid 0.7 percent at the close in New York. Delta and US Airways blamed sequestration this week for shortfalls in a benchmark revenue gauge in March.The drop in airline stocks because of sequestration is "unwarranted," Helane Becker, an analyst at Cowen Securities in New York, wrote Friday.