Efforts to replace live evacuation trials with computer modelling are being hampered by incomplete information
Cabin safety experts are warning that greater use of computer simulations of cabin evacuation is being hampered by the large airframers' lack of willingness to share data.
Speaking at last week's Triennial International Fire and Cabin Safety Research Conference in Lisbon, Portugal, Ed Galea, director of the Fire Safety Engineering department at the UK«s Greenwich University, said aerospace lags behind other sectors, including maritime and construction industries, in its acceptance of computer models when certificating evacuation procedures.
Galea says the large aircraft manufacturers are reluctant to abandon the full-scale, one-off live trials, in case more detailed evaluations reveal shortcomings. "They are not going to take on the additional regulatory burden without it being made mandatory," he says.
According to sources at Embraer, the manufacturer wanted to make greater use of evacuation modelling in the certification of its 190 regional jet, but was unable to gain access to enough data from other airframers' trials to make its model sufficiently detailed for Brazilian airworthiness authority CTA to accept.
Galea says regulations, such as the requirement that all passengers be evacuated in under 90s or the US Federal Aviation Administration's so-called "60ft rule" on the maximum distance between exits, could be proved to be irrelevant by more detailed modelling.
He believes the lack of realism inherent in live trials, due to the co-operative nature of volunteers, the lack of groups of passengers and lack of disabled people, is attractive to the large manufacturers.
With live trial costs running at around $2 million for a large transport aircraft like the Airbus A380, experts say manufacturers could be convinced by the cost savings associated with the use of modelling.
Galea is proposing a three-stage approach to greater use of modelling, with data taken from live trials used to back up models for information purposes, followed by a partial then full reliance on modelling only when data is sufficient. The benefits would include more realistic scenario modelling, such as evacuation of disabled passengers, cabin fires and ditching.
JUSTIN WASTNAGE / LISBON
Source: Flight International
