Washington: The United States has lost seven multi-million-dollar MQ-9 Reaper drones in the Yemen area since March 15, a US official said Monday, as the Navy announced a costly warplane fell off an aircraft carrier into the Red Sea. Washington launched the latest round of its air campaign against Yemen’s Huthis in mid-March, and MQ-9s can be used for both reconnaissance — a key aspect of US efforts to identify and target weaponry the rebels are using to attack shipping in the region — as well as strikes. “There have been seven MQ-9s that have gone down since March 15,” the US official said on condition of anonymity, without specifying what caused the loss of the drones, which cost around $30 million apiece. The US Navy meanwhile announced the loss of another piece of expensive military equipment: an F/A-18E warplane that fell off the USS Harry S. Truman aircraft carrier in an accident that injured one sailor. A tractor that was towing the F/A-18E — a type of aircraft that cost more than $67 million …