Delta Air Lines reported its first quarterly profit since the pandemic devastated the airline industry more than a year ago, as hordes of vacation travelers and money from U.S. taxpayers offset weak corporate and international travel. Delta said Wednesday that it earned $652 million in the second quarter. However, Delta’s report shows that airlines still face turbulence as they try to rebound from their worst year ever. Without $1.5 billion in federal pandemic relief and other one-time events, the Atlanta airline would have posted an adjusted loss of $678 million. Even though crowds at the nation’s airports are approaching 2019 levels, Delta’s operating revenue is still only half of pre-pandemic levels. And the company expects costs to rise as it rebuilds its operation, including hiring and training employees to handle the growing number of passengers. “We still have a long ways to go,” CEO Ed Bastian said in an interview, …