The Evaluation of the 90 Second Certification Test and the Analysis of Human Behaviour Within Aircraft Evacuation Modelling

Madeleine Togher

2014

Abstract

The majority of fatalities during an aircraft accident occur after impact with approximately 95% due to burns and smoke inhalation due to sub optimal evacuations. If post-crash survivors can be evacuated quickly enough then the survival rate could be improved. This thesis will examine the influence of exit availability on the evacuation of narrow bodied aircraft during 90 second certification trials; carried out by aircraft manufacturers. These trials are carried out using one exit from each exit pair usually along one side of the aircraft. Analysis in the thesis will look at the effects of still using 50% of the exits but while using a different combination of available exits which may be closer to real accident scenarios. The analysis will make use of the airExodus evacuation model and will use the geometry of a narrow bodied aircraft cabin of a Boeing 737-300 containing two type C exits, two Type B exits, and two Type III exits with a maximum loading of 149 paxs. A decreasing order of likelihood of exit availability found during real emergency evacuations according to the Aircraft Accident Statistics and Knowledge database (AASK) V4.0 holds information from 105 survivable aircraft accidents with over 2000 survivors was used as a basis for choosing the exit zones used during this analysis. Similar analysis was also carried out on a wide bodied aircraft using the geometry of a Boeing 777-200 series aircraft with a loading of 440 paxs and 8 Type A exits.

This thesis also presents results from a questionnaire study of participant exit awareness and suggested exit selection during the event of an emergency aircraft evacuation involving a narrow bodied aircraft. The questionnaire study involved 459 participants with a number of levels of flight experience. The results of the study has supported the hypothesis that paxs have a poor understanding of where exits are located together with their relative size and flow rate and may be the contributing factor to poor exit decisions made by paxs during emergency aircraft evacuations. These results, have implications for the airlines while providing a better insight for evacuation model developers with regards to the decision making process carried out by agents in their exit selection.

Finally this thesis concludes by demonstrating the validation of data gathered and analysed from participants involved in the questionnaires and implemented into the airExodus evacuation model and by evaluating the current certification process in proving the safety of the aircraft which undergo this test.
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