Threat assessment of hazardous materials transportation in aircraft cargo compartments

The Volpe National Transportation Systems Center of the U.S. Department of Transportation's (DOT) Research and Special Programs Administration (RSPA) has conducted a quantitative threat assessment for RSPA's Office of Hazardous Materials Safety (OHMS) to determine the probability of a life-threatening incident occurring as the result of transporting hazardous materials in aircraft cargo compartments. The study team developed a threat assessment model using an event tree method and threat scenarios that were refined with the assistance of a panel of experts, which contributed potential countermeasures, suggested experimental tests, and provided input data for the model. Additional input was developed from data collected by OHMS, the Volpe study team, and support contractors. The threat scenarios were developed using three possible cases: (a) packages that comply with DOT regulations for shipment on passenger flights, (b) packages that comply with DOT regulations for shipment on cargo-only flights; and (c) packages that do not comply with DOT regulations for air transport. Materials chosen for each hazardous material class and division represented the worst-case situation for air shipments (materials that are among the more dangerous in their class or division, commercially available. and likely to be transported by air). The specific chemical, physical, and toxicological properties of these materials were used as input. The model calculated the likelihood of life-threatening incidents on the basis of a package containing the selected material being on board, specific cargo compartment type, and the package's state of compliance.