To prevent unsafe congestion of sightseeing aircraft is one objective of which aviation process?

The objective of preventing unsafe congestion of sightseeing aircraft is primarily addressed through the implementation of Temporary Flight Restrictions (TFRs). TFRs are designed to manage air traffic around specific locations, particularly during events that could lead to an increase in aircraft activity, such as air shows, natural disasters, or other notable events where large numbers of people or aircraft are in the vicinity. By establishing these restrictions, air traffic control can designate specific areas where aircraft are not allowed to fly or dictate specific altitudes and routes to ensure safety and minimize the risk of mid-air collisions.

The other options do play roles in aviation safety and operations, but they do not specifically target the congestion issue that TFRs are designed to mitigate. Flight planning focuses on the preparation aspect of a flight, while sectional chart depiction pertains to visual navigation aids and the representation of navigational data. Airspace classification involves categorizing airspace into different types based on usage and operational requirements, but it does not directly control traffic flow in the same immediate sense that TFRs can. Thus, TFRs are crucial for maintaining safe distances between sightseeing aircraft and managing the overall safety of the airspace during high-traffic situations.