Business U.S. airline executives on Monday pointed to concrete signs of a domestic leisure travel recovery as a slowing pandemic drives spring and summer bookings, pushing shares to their highest level since the coronavirus crisis hit the sector a year ago. “We certainly are seeing the beginning of what feels like a very large uptick,” said American Airlines Chief Executive Doug Parker, one of several CEOs speaking at a J.P. Morgan conference. Ted Christie, CEO of budget carrier Spirit Airlines, said the recovery appeared to “have legs.” Executives cited data showing that U.S. COVID-19 vaccinations are accelerating and have outstripped the number of positive cases, which are on the decline.