Abstract: An aircraft having a plurality of fuselage members, one of which is provided with a replaceable and interchangeable payload carrying section. The replaceable section may be adapted to contain various equipment, ordinance and the like to satisfy different aircraft mission requirements. The replaceable and interchangeable sections are adapted to become an integral part of the fuselage section to which it is attached and permits the payload to be located in proximity to the aircraft's center of gravity such that variations in the equipment that constitutes the payload or discharge of all or part of the payload from the replaceable fuselage section will not substantially alter the aircraft's center of gravity.