If the longest aircraft has fewer than 5 average daily departures, the ARFF index is determined by which?

• A. the index above the longest aircraft serving the airport
• B. the index below the longest aircraft serving the airport
• C. the index of the top-of-the-line aircraft
• D. the index we choose by random

Answer: (B)

ARFF index is based on the largest aircraft that uses the airport and how often it operates. If that aircraft has fewer than five average daily departures, the index is taken from the category below the longest aircraft serving the airport. This keeps the firefighting and rescue capabilities aligned with typical operations rather than with a rare, very large aircraft visit. For example, a jumbo jet that only flies a couple of times per day would set the ARFF index for the next smaller category rather than the largest aircraft. The other options would either overstate resources or ignore the established rule that the index should reflect actual, regular operations.