What type and amount of firefighting agents must an airport have if it operates under FAR Part 139?

The correct choice provides the specific requirements for firefighting agents that an airport must maintain under FAR Part 139, which deals with certification of airports in relation to transport category aircraft. This regulation mandates that certain sizes and classes of airports have predetermined quantities of firefighting agents to ensure safety in the event of an aircraft incident.

Specifically, the requirement includes either 500 pounds of dry chemical (DC) or Halon 1211, which is an extinguishing medium capable of combating flammable liquid fires, or alternatively, a combination of 450 pounds of dry chemical and 6,000 gallons of water. The inclusion of both dry chemical agents and a significant volume of water is important because water acts as a cooling agent and helps control fire spread. This combination ensures that airports are equipped to handle various types of fire scenarios, particularly those associated with aviation incidents.

Other options do not comply with the FAR Part 139 standards for the specific amounts and types of firefighting agents required. They either underrepresent the total weight and volume of the agents or do not meet the guidelines set forth for effective firefighting capabilities. Understanding the specifics of these requirements is essential for maintaining safety and compliance at certified airports.