Large airtanker use in the United States: what do we know?

Abstract

In this paper we will review recently uncovered trends in large airtanker (LAT) use in the U.S., explore implications, and discuss opportunities for improving efficiencies. First, we will review results of two studies attempting to characterize LAT use between initial attack (IA) and extended attack and/or large fire support (EA) missions. Collectively these studies identified significant LAT use for EA despite a history of prioritizing LATs for IA, and further identified potentially counterintuitive results where fires receiving LAT support during IA were more likely than not to escape IA efforts. These results suggest potential operational efficiencies in LAT use, and that improving success in IA efforts may be in part premised on reducing the time between ignition and LAT arrival on the fire. Here we examine trade-offs between LAT usage for IA and LAT unavailability for IA operations due to EA use. To do so we use a mathematical optimization model to identify efficient LAT air base location and deployment strategies. The model is designed to minimize the total deployment time of meeting LAT IA demand, with demand quantified as a function of a fire weather index. Results indicate, as expected, that model performance degrades as LATs are increasingly unavailable. Results further indicate substantial sensitivity of LAT air base location strategy to LAT availability, with potentially significant implications for air base staffing and capacity decisions, as well as fleet composition decisions. To conclude we will describe ongoing and future work analysing opportunities for efficiency gains in LAT management, focusing on the role of forecasting and optimization frameworks, as well as ongoing data collection and analysis regarding retardant drop conditions and outcomes.