Flight 800 Report Due Out In August / NTSB
to blame blast generally on fuel tank
It took four years and 36 days, $35 million and hundreds of hours of
researchers from New Mexico to Norway.
Next month, in a long-awaited move, the National Transportation Safety
will publicly present a report the size of a phone book designed to
rest once and for all the dispute about the cause of the crash of TWA
The report is still in a draft form and has not yet been sent to the
members of the board, who will vote on whether to adopt it at the end
two-day board meeting scheduled for Aug. 22-23. The final report on
800 is expected to blame the crash on a fuel tank explosion without
specifying exactly what ignited vapors in the tank of the Boeing 747,
according to NTSB sources.
For years, investigators have been warning that they might not be able
pinpoint the source of the ignition. The July 17, 1996, crash off the
of Long Island has been "the most intensely investigated accident in
history," Elizabeth Erickson, director of aircraft certification for
Federal Aviation Administration, told reporters last week as she gave
presentation on the FAA's recent moves to make fuel tanks safer. "But
ignition source for that explosion remains unknown."
Rather than single out one source for the spark that triggered the blast,
final report on Flight 800 will outline several ways in which components
inside the fuel tank can fail-because of aging or contamination-and
explosion. In the case of a crash once considered to be the result
criminal act, the scenarios laid out by the NTSB may not satisfy the
But that shouldn't matter, some aviation experts say.
"It satisfies me," said C.O. Miller, a former director of aviation safety
the NTSB. The exact cause of an accident, he said, is less important
determining a list of potential causes. That way, all the dangers can
eliminated,not just the one that caused one particular crash.
"The important thing is that you identify the hazards," Miller said.
The safety board has already issued 10 safety recommendations to the
based on the investigation, and the FAA is moving forward on many of
Next month, the agency will conduct flight tests in a Boeing 737 to
the effectiveness of pumping nitrogen into the tank to prevent explosive
vapors from building up. Erickson said the FAA could be ready to issue
rules next year to eventually require nitrogen in fuel tanks, which
a major change for the industry.
The NTSB's final report is expected to contain more safety recommendations
stemming from the Flight 800 investigation. And while the FAA does
to follow the recommendations, it is in forums such as this-a final
meeting-that the NTSB is able to put additional public pressure on
The report will not be short on details. Expected to be several hundred
long, it will contain descriptions of an experiment in a full-scale
detect electromagnetic interference in electrical components, as well
experiment that involved shooting missiles off the coast of Florida
document what witnesses might see.
From a painstaking metallurgical study of the wreckage that sits in
Calverton hangar, investigators even know the exact place where the
of the giant plane first began to split from the force of the explosion,
triggering a series of tears that caused the plane to break apart in
killing 230 people.
The report will contain details on an experiment conducted last year
Wright-Patterson Air Force Base showing that if damaged wiring outside
fuel tank caused a high voltage to enter a fuel- measuring system inside
tank, a film of copper-sulfur deposits - which can build up on fuel
components over time-can sustain enough energy to spark an explosion.
The NTSB is also expected to bring up concerns about the way aircraft-makers
analyze potential failures, as now required for FAA certification.
analysis, sometimes called a fault tree analysis, is a numerical calculation
of potential failures on the aircraft. It is designed to ensure that
single failure is capable of bringing down the plane, the chances of
occurring are no more than one in a billion flight hours.
The safety board has raised concerns about a Boeing's fault tree analysis
fuel tank safety, done as part of the investigation. NTSB sources say
board is concerned that the numbers used are not based on actual failure
rates. In a letter to the FAA, NTSB Chairman Jim Hall said the safety
asked an outside expert from NASA to review Boeing's analysis. Amanda
Goodson, NASA's director for safety and mission assurance, said in
to the NTSB that the analysis "cannot stand up to peer review and should
be viewed as realistic."
The NTSB's final report will be considered a draft and will not be made
public until after the board votes to adopt it. Three of the five board
members must vote in favor of the report; it's rare that the NTSB's
reports do not get adopted, although portions are often rewritten before
board meetings based on members' concerns.
Watching closely will be the lawyers who are representing victims' families
in the case. Although the attorneys are not allowed to use the probable
in court, they can use the factual material presented.
"It's going to be the NTSB's attempt to close the record, but it's going
be just like the JFK assassination," said Vernon Grose, a former member
the NTSB. "It's going to be viewed as an ongoing conspiracy."
© Copyright 2000, Newsday Inc.
Sylvia Adcock. STAFF WRITER, Flight 800 Report Due Out In August / NTSB
blame blast generally on fuel tank, 07-16-2000, pp A03.
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