What is provided only to aircraft operating in accordance with a Letter of Agreement (LOA)?

Preventive control is specifically designed for aircraft operating under a Letter of Agreement (LOA). This type of control allows for tailored strategies between air traffic control facilities and pilots, ensuring that aircraft can be managed with more comprehensive measures than those typically extended to standard operations.

Through LOAs, certain operational procedures may be agreed upon that provide additional flexibility and resources, enabling air traffic controllers to implement preventive measures effectively. This can include managing airspace more dynamically or providing enhanced services that may not be available to all aircraft.

The other choices, while relevant to air traffic control, do not encapsulate the specific set of enhanced operational measures associated with an LOA. Preventive notification and traffic advisories refer to standard communications and alerts that can be given to all aircraft, while authorized access pertains more generally to permitted operations rather than the specific conditions set by an LOA. Thus, preventive control stands out as the unique service afforded only to those aircraft involved in such agreements.