All Nippon Airways (ANA) has said it will pursue Boeing for its losses due to the 787 groundings, which so far amount to $15.4m. The carrier cancelled around 850 flights over the last month alone, during which it sustained the losses. ANA is the 787’s biggest customer with 17 of the aircraft in its fleet. "We will negotiate with Boeing," confirmed ANA’s CFO, Kiyoshi Tonomoto. The costs, though high, account for only three per cent of the airline’s forecasted annual earnings. “It is not small, but it is not that great,” Tonomoto said. Japan is sending two independent and official investigators to Seattle this weekend to meet with Boeing over the 787 batteries in the hope they will find the cause of the battery fires.