7-16-00

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 work by 
researchers from New Mexico to Norway. 

Next month, in a long-awaited move, the National Transportation Safety Board 
will publicly present a report the size of a phone book designed to lay to 
rest once and for all the dispute about the cause of the crash of TWA Flight 800. 

The report is still in a draft form and has not yet been sent to the five 
members of the board, who will vote on whether to adopt it at the end of a 
two-day board meeting scheduled for Aug. 22-23. The final report on Flight 
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 to 
pinpoint the source of the ignition. The July 17, 1996, crash off the coast 
of Long Island has been "the most intensely investigated accident in aviation 
history," Elizabeth Erickson, director of aircraft certification for the 
Federal Aviation Administration, told reporters last week as she gave a 
presentation on the FAA's recent moves to make fuel tanks safer. "But the 
ignition source for that explosion remains unknown." 

Rather than single out one source for the spark that triggered the blast, the 
final report on Flight 800 will outline several ways in which components 
inside the fuel tank can fail-because of aging or contamination-and cause an 
explosion. In the case of a crash once considered to be the result of a 
criminal act, the scenarios laid out by the NTSB may not satisfy the public.. 

But that shouldn't matter, some aviation experts say. 

"It satisfies me," said C.O. Miller, a former director of aviation safety for 
the NTSB. The exact cause of an accident, he said, is less important than 
determining a list of potential causes. That way, all the dangers can be 
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 FAA 
based on the investigation, and the FAA is moving forward on many of them. 
Next month, the agency will conduct flight tests in a Boeing 737 to determine 
the effectiveness of pumping nitrogen into the tank to prevent explosive 
vapors from building up. Erickson said the FAA could be ready to issue new 
rules next year to eventually require nitrogen in fuel tanks, which would be 
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 not have 
to follow the recommendations, it is in forums such as this-a final board 
meeting-that the NTSB is able to put additional public pressure on 
regulators. 

The report will not be short on details. Expected to be several hundred pages 
long, it will contain descriptions of an experiment in a full-scale 747 to 
detect electromagnetic interference in electrical components, as well as an 
experiment that involved shooting missiles off the coast of Florida to 
document what witnesses might see. 

From a painstaking metallurgical study of the wreckage that sits in a 
Calverton hangar, investigators even know the exact place where the fuselage 
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 midair, 
killing 230 people. 

The report will contain details on an experiment conducted last year at 
Wright-Patterson Air Force Base showing that if damaged wiring outside the 
fuel tank caused a high voltage to enter a fuel- measuring system inside the 
tank, a film of copper-sulfur deposits - which can build up on fuel tank 
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. The 
analysis, sometimes called a fault tree analysis, is a numerical calculation 
of potential failures on the aircraft. It is designed to ensure that if any 
single failure is capable of bringing down the plane, the chances of it 
occurring are no more than one in a billion flight hours. 

The safety board has raised concerns about a Boeing's fault tree analysis on 
fuel tank safety, done as part of the investigation. NTSB sources say the 
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 board 
asked an outside expert from NASA to review Boeing's analysis. Amanda 
Goodson, NASA's director for safety and mission assurance, said in a letter 
to the NTSB that the analysis "cannot stand up to peer review and should not 
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 staff 
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 cause 
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 to 
be just like the JFK assassination," said Vernon Grose, a former member of 
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 to 
blame blast generally on fuel tank, 07-16-2000, pp A03.

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