"Non-Movement Area" of the airport, the part of the airport ramp where ramp agents can operate. Ramp agents cannot operate within the Movement Area, reserved for aircraft and emergency equipment, which is controlled by the Air Traffic Control Tower. In some union-negotiated airlines or stations this job could also be done by the baggage handler. Various jobs of handlers Operations (load control) agent An aircraft has weight and balance limitations in order to ensure safe operation. There is a limit to how much a loaded aircraft can weigh; in addition, the cargo, passenger and fuel load must be distributed so that the aircraft is "in balance"—in other words, not too nose-heavy or tail-heavy. One of the jobs of the operations agent is to ensure that the aircraft—as finally loaded—is "legal" (within safe limits) before the aircraft departs the gate. Upon satisfaction of this mandated requirement, that data is used to generate information which the pilot requires in order to ensure the safe operation of the aircraft. Warehouse agent The air freight warehouse is where inbound and outbound air freight is processed. It is usually located on or adjacent to airport property and is usually separate from the passenger terminal. This is a secure (sterile) area where only authorized persons are allowed access. If inbound international shipments are involved and have not been cleared by customs, those shipments (and the warehouse) may be "in bond", which requires additional security clearance/authorization of employees. Crew chief Responsible for many different job functions; usually a team of rampers who report directly to him or her. Crew chiefs are responsible for ensuring that an aircraft has been loaded to the specifications of the load agent, and reporting any discrepancies to management. Usually this job has a premium rate of pay for the extra responsibilities. Ramp agent The people working on the ramp, typically seen loading bags, are referred to as "ramp agents". Among other duties, they must ensure that arriving aircraft are unloaded promptly. The ramp agents will also load departing aircraft. They must sometimes account for the baggage loaded into each compartment to ensure proper weight and balance, although this job is often the responsibility of flight operations staff. Transfer agent This term is loosely used to refer to any agent who operates a vehicle that is used to transfer bags from one aircraft to another or to carry bags from the "bag room"