Qatar Airways, which is the only Gulf carrier that never stopped flying to the US during the pandemic, is resuming flights to Houston and Philadelphia. The carrier had expanded frequencies to daily to Los Angeles on Aug. 12 and will double its daily flights to New York (JFK) on Sept. 1. Qatar will add three weekly flights to Houston beginning Sept. 2 and four weekly flights to Philadelphia on Sept. 15. That will mean the airline’s US operations will stand at eight gateways, including Boston, Chicago, Dallas-Fort Worth and Washington, D.C.  Through its partnerships with US carriers, Qatar currently enables passengers to book onward travel with American Airlines on more than 600 daily flights and with JetBlue on more than 70 daily flights. That will expand substantially by mid-September. Akbar Al Baker, group chief executive of Qatar, said the additions maintain the airline’s position as the largest international carrier in the US “and we look forward to soon returning to all 10 of our incredible US gateways.”