Investigators of the TWA-800 aircraft disaster are studying the possibility that it was caused by electromagnetic pulses from military craft. If the theory is proved, ,ilitary aircraft would be regarded as a threat to all civilian flights.On July 17, 1996, the jumbo jet exploded en route from New York to Paris. All 230 passengers and crew were killed. The same day, 10 United Stated Navy ships and Air Force planes are known to have been operating aound Long Island.
Experts say powerful radar or radio bursts from any of these could have burnt out circuits on the Boeing 747, caused rudders or airfoils to move suddenly, or triggered fuel explosions. This idea is feasible, says James Hall, chairman of the US National Transportation Safety Board.
He said his investigative team was working "to determine the effects of electromagnetic interference and high-intensity radiated fields on 747s", and hoped to report later this year -- although his investigation is being hampered because servicemen cannot give evidence "for security reasons".
Missiles, bombs, and mechanical failure were suspected as causes after the TWA-800 disaster. The safety board's inquiry intoo the accident has yet to make an official ruling, but the first two suggestions have been rejected after an 18-month FBI investigation. In November, James Kallstrom, the agency's assistant directoor, said streaks seen by witnesses were pieces of the plane breaking away, not a missile heading toward it.
"Following 16 months of unprecedented investigation. we must now report that no evidence has been found which would indicate that a criminal act was the cause."
It was then though that a catastrophic technical failure in the 747 was responsible. Safety board inspectors say they suspect an electrical spark in the central fuel tank of the 25-year-old jumbo caused it to explode. But they are still unable to pinpoint the source of the spark.
Now a group of experts say it may have been triggered by an electromagnetic pulse from one of the military craft in the vicinity of the TWA-800 at the time of the accident.
The prime exponent of this theory is Elaine Scarry, whose 18-page investigation, The Fall of TWA-800, was published in the New York Review of Books a few weeks ago. Her analysis is detailed and convincing.
Far more startling, however, is the follow-up correspondence generated between Scarry and NTSB chairman Hall, which will be published in the next issue of the New York Review of Books . In one letter, Hall acknowledges for the first time that an American military craft coiuld have been responsible, albiet inadvertently, for the destruction of a civilian airliner and the deaths of its passengers, including 16 high school students from rural Pennsylvania and holiday-makers returning to France and Italy.
"Work is under way to examine threats that may have resulteed from an external surface or airborne (high-intensity radiated field) source. This is a challenging undertaking that involves an understanding of military emitters, as well as considerable number of civilian transmitters near the accident site. We hope to complete these activities within the next six months," Hall wrote in a letter dated May 27.
In her original investigation, Scarry points out that an electromagnetic field, such as that produced by military planes or ships on exercise, can directly burn out circuits. At high enough levels "it can even generate an electrical spark", she writes.
This knowledge suggests several different scenarios, of which the first two are considered more likely. First, vapour in the plane's fuel tanks could have been ignited directly by sparks generated in voltage lines that were swept by electromagnetic fields produced by military craft.
Second, a pulse could have knocked out instruments, causing the 747 to spin out of control. "Once a plane starts to fall, tearing metal anywhere on the body of the place can generate sparks and thise sparks might have ignited an explosion on the central fuel tank," she writes. As part of her evidence, she quotes a 1984 Nasa report which revealed that electromagnetic pulses produced during military flights often have inadvertent effects on civilian aircraft. "The exclusion of this subject from the TWA-800 inquiry would be understandable if some other cause had quickly come forward as an explanation," Martin Schooman, author of the Nasa report, says. "But that didn't happen. The possibility of a high-intensity radiation field event must be given very careful consideration."
The final answer to the mystery, Scarry says, lies with the servicemen who were operating ships and aircraft near the accident zone but who have forbidden to give evidence for security reasons.
"A democracy requires the military to be held within a civil frame and the military to be accountable to civilians."
