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Static electricity theory weakens as cause of TWA 800 crash
February 14, 1997Web posted at: 10:53 p.m. EST
Latest developments:
- Initial tests fail to produce spark
- U.S. planes may use anti-static additive
- 'They have to find the cause...'
NEW YORK (CNN) -- It is not looking good for the electrostatic buildup theory as the cause of the crash of TWA Flight 800.
CNN has learned that a preliminary test by the National Transportation Safety Board (NTSB) failed to produce the kind of static buildup in fuel lines necessary to ignite an explosion in the plane's fuel tank.
The initial tests were conducted at the laboratories of the Boeing Company in Seattle. Boeing manufactured the 747 involved in the crash.
A source at the NTSB warns that the completed tests are just the first of a series to determine whether a buildup of electrostatic electricity could have caused the explosion that led to the crash on July 17, 1996. All 230 people aboard the flight from New York to Paris died.
Investigators say a charge could have built up as fuel moved through the center fuel tank in an aluminum pipe called the cross-feed manifold. But in the initial tests, the fuel was too slow to generate enough energy to cause a spark that could ignite the fuel.
Whether a leak in the manifold caused fuel spray to enter the center tank and create a spark has not yet been tested, although it is one of the theories being considered.
U.S. planes may use anti-static additive
Officials began giving static electricity serious attention because jet fuel used in the United States does not contain anti-static additives. Many other countries use additives to minimize the risk of explosion during fueling, and in the event of fuel leaks.
The NTSB may recommend to the Federal Aviation Administration that anti-static additives be used in jet fuel in this country as well.
Another possible recommendation would affect the maintenance and inspection procedures airlines use to check on the effectiveness of grounding systems.
NTSB investigators will examine whether large metal fuel line couplings -- which are not grounded to the aircraft -- could have collected an electrical charge.
"The coupling was potentially ungrounded and could be an unbonded charge collector," says fuel expert Cyrus Henry. "It could retain a charge which could ignite a fuel mixture."
'They have to find the cause...'
Earlier this week, a government commission urged the FAA to expand its aging aircraft program to cover electrical and electro-mechanical systems among others.
In the meantime, NTSB officials tell families of TWA 800 passengers they are still stumped about the cause of the crash.
"It's just not possible to have an accident of this magnitude remain undetermined," says Jose Cremades, the father of a TWA crash victim. "They have to find the cause, and they have to take measures to prevent it."
Correspondent Christine Negroni contributed to this report.
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Related stories:
- Six months later, still no answer to TWA Flight 800 mystery - January 17, 1997
- TWA crash investigators to begin tests - January 7, 1997
- Flight 800 lawsuit puts focus on fuel pump - December 26, 1996
Related sites:
Note: Pages will open in a new browser window- TWA Flight 800 memorial
- National Transportation Safety Board
- Federal Bureau of Investigation
- Electrostatic Discharge - U.S. Air Force
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