What key factor determines the classification of an aircraft fire according to the NFPA?

The classification of an aircraft fire according to the NFPA (National Fire Protection Association) primarily hinges on the type of fuel involved. Aircraft fires can involve various types of fuels, including aviation gasoline, jet fuel, and other combustible materials. Each fuel type has unique characteristics that influence the fire's behavior, spread, intensity, and mitigation strategies.

Understanding the fuel type is crucial for determining the appropriate firefighting methods and equipment required to effectively combat the fire. For instance, certain firefighting agents may be more effective against specific fuels, while others could exacerbate the situation.

While factors such as the aircraft's size, the fire's location, and the number of personnel responding may be relevant to the context of firefighting efforts, they do not play a direct role in the classification of the fire itself as dictated by NFPA standards. The nuances of fuel types and their fire behavior are pivotal for ensuring safety and effective response from airport firefighters.