Fowler Associates Labs

By: Elizabeth Nelson

Last month, a Boeing 737 was destroyed while on the ground in Bangkok. Recently, preliminary evidence has determined that the explosion had the same cause as the TWA Flight 800 that went down off the New York coast in 1996. Last year, it was ruled that the TWA plane broke in half after a center fuel tank explosion. 230 people were killed because of this explosion. It is suspected that a frayed wire or another source, such as ESD, led to a spark in hot fuel vapors.

According to CNN, a lead investigator for the U.S. National Transportation Safety Board has commented that a possible source of ignition may be caused by static electricity in the fuel tank. At this time, ESD has not been ruled out for either the TWA or the Boeing 737 explosions.

The US National Transportation Safety Board (NTSB) explains that the cause of the explosion is linked to the plane's fuel tank. The Thai Airway International 737 exploded on March 3, 2001 and the NTSB has been helping Thai authorities determine the cause because of their expertise dealing with airplane explosions.

The explosion of the Boeing 737 is also similar to an explosion on a Philippine Airlines 737 that exploded in 1990. According to the NTSB, the voice recorder in the Boeing 737 recorded similar noises as those heard in the Philippine Airlines 737.

Steps are currently being taken to reduce the chances of fuel tank explosions. The NTSB recommends that one way to prevent these types of explosions is to switch air condition to off while the plane is on the ground. Because the air conditioning units emit heat, it is possible for this heat to vaporize the fuel in the tank and for the fuel to become explosive. Boeing has began to warn customers on their flights to leave their air conditioning off while on the ground.

Unfortunately, in both the TWA and Thai explosions, the air condition unit adjacent to the center tank was in the on position. According to the NTSB, the Thai Airways International 737 had been running the air conditioning for about 40 minutes on the ground. The outside temperature the day of the explosion was over 90 degrees.

Currently, Boeing's advice of leaving the air off while grounded is not a federal rule, so many air carriers have not been following the advice.