SUMMARY OF HEARING: Friday, December 12, 1997

Ways to reduce flammability in fuel tanks were examined in the last day of the week-long NTSB hearing into the explosion of TWA flight 800, with witnesses saying that measures being weighed included using less volatile fuel and inserting foam or inert gas into tanks to force out dangerous jet fuel fumes.

NTSB Chairman Jim Hall closed the meeting saying that the Board would continue advocating a two-track approach to the problem – reducing the volatility of jet fuel and making sure there is no ignition source in fuel tanks that could trigger an explosion.

The NTSB has determined that the plane’s center wing tank exploded, but has not yet determined what touched off the explosion. Ignition sources were taken up earlier in the week.

Hall said he was appreciative of all the work done to remove all potential ignition sources from center fuel tanks, but since it can never be certain all the sources are removed, additional measures are needed to reduce or eliminate the explosive potential of fuel tank vapors.

The chairman said that as the investigation continues, he was confident "we will learn a great deal more that will help make our air transportation system even safer."