A number of US Navy F-18 fighter planes will be flying out of the Vermont Air National Guard base in South Burlington this month. The guard said the Navy F-18s will fly from the Burlington International Airport between July 8 and 11 and between July 15 and 18. Navy pilots and their aircraft will conduct joint operations for Vermont Air Guard pilots in their F-16s. The Guard said there could be some additional aircraft traffic in the area during the operations.