Computer modelling of human behaviour in aircraft fire accidents.

The mathematical simulation of the evacuation process has a wide and largely untapped scope of application within the aircraft industry. The function of the mathematical model is to provide insight into complex behaviour by allowing designers, legislators, and investigators to ask 'what if' questions. Such a model, EXODUS, is currently under development, and this paper describes its evolution and potential applications. EXODUS is an egress model designed to simulate the evacuation of large numbers of individuals from an enclosure, such as an aircraft. The model tracks the trajectory of each individual as they make their way out of the enclosure or are overcome by fire hazards, such as heat and toxic gases. The software is expert system-based, the progressive motion and behaviour of each individual being determined by a set of heuristics or rules. EXODUS comprises five core interacting components: (i) the Movement Submodel -- controls the physical movement of individual passengers from their current position to the most suitable neighbouring location; (ii) the Behaviour Submodel -- determines an individual's response to the current prevailing situation; (iii) the Passenger Submodel -- describes an individual as a collection of 22 defining attributes and variables; (iv) the Hazard Submodel -- controls the atmospheric and physical environment; and (v) the Toxicity Submodel -- determines the effects on an individual exposed to the fire products, heat, and narcotic gases through the Fractional Effective Dose calculations. These components are briefly described and their capabilities and limitations are demonstrated through comparison with experimental data and several hypothetical evacuation scenarios.