Major US carriers lifted their revenue forecasts Tuesday as a faster-than-expected travel recovery from the latest Covid-19 wave mitigates the drag from higher jet fuel costs. American Airlines, Delta Air Lines, United Airlines and Southwest Airlines all offered similar appraisals of market conditions in presentations at an investment conference Tuesday. American now expects first-quarter revenues to be down 17 percent compared with the 2019 period, after previously projecting a drop of as much as 22 percent. “The improvement in revenue is expected to more than offset the increases in fuel and…