Delta this year carried the most passengers in a summer ever, despite a computer outage in August, CEO Ed Bastian said Friday. "We had the strongest summer in our history," Bastian said, adding that three days in July "set all-time records in terms of volume of traffic and volume of passenger flows." Bastian's comments come after Delta reported declines during the summer months in unit revenue, which tallies the amount of passenger revenue per available seat-mile. Bastian said traffic was up because fares were about 6% lower than last year. That meant revenue per passenger was down, but the airline's profit margins were "still strong," he said. Bastian also criticised subsidies that he said airlines in Qatar and United Arab Emirates have received from their governments, stifling US competition. On Friday, Bastian said the subsidy levels had reached $50b among the Qatar Airways, Etihad Airways and Emirates airline, and have made it uncompetitive for US airlines to fly to Dubai, Abu Dhabi and Doha. The Gulf-based carriers dispute that view, saying they have received investments, not subsidies.<br/>