FAA: Changes will be considered in 747s
Action in response to NTSB recommendations after TWA 800
December 3, 1997
Web posted at: 10:42 p.m. EST (0342 GMT)
WASHINGTON (CNN) -- The Federal Aviation Administration
announced Wednesday that it is considering requiring
modifications in Boeing 747 jets to reduce the possibility of
center fuel tank explosions.
Those recommendations were among a list of changes requested,
on an "urgent" basis, by the National Transportation Safety
Board more than a year ago in the wake of the crash of TWA
Flight 800, which investigators suspect may have been felled
by a fuel tank explosion.
But most of the modifications are still at least six months
away, and the FAA has rejected several other changes that the
The NTSB investigates airline crashes, while the FAA
regulates the airline industry. The NTSB can recommend
changes to the FAA but cannot mandate them.
In the near term, the FAA is expected to order mandatory
inspections of center fuel tanks for structural, plumbing and
wiring problems. And FAA Administrator Jane Garvey, in a
letter to NTSB Chairman James Hall, said a "fast track"
advisory committee would be created to study specific ways to
decrease the risk of center fuel tank explosions.
The committee would include aviation industry experts and
representatives from consumer and union groups, according to
Garvey. It would be given six months to return with
recommendations so that the FAA could "make appropriate
judgment and decisions on further action expeditiously," she
One possibility to be studied would be the installation of
systems that insert nitrogen into empty tanks, to replace
explosive vapors, and the addition of insulation between
heat-generating equipment on the jet and fuel tanks, the
However, Garvey said in her letter that the FAA has rejected
an NTSB recommendation that certain levels of fuel be kept in
center tanks and that systems be installed to monitor fuel
The NTSB suggested that refueling the tanks before takeoff
with cooler fuel would decrease the volatility of fuel
vapors, and that keeping the fuel level higher would reduce
the vulnerability to explosion. But the FAA concluded these
measures would provide no significant benefit.
The FAA also said temperature monitors in the fuel tanks
would not be helpful because there is no "practical" way for
the pilot to reduce the temperature. The monitor would just
be another gauge for the crew to watch in an already crowded
cockpit, and the wiring inside the tank "would add another
possible source of tank ignition," the FAA said.
TWA Flight 800, bound from New York to Paris, exploded on
July 17, 1996, in the skies over Long Island Sound, killing
all 230 people on board.
Though no final cause of the crash has been determined, NTSB
investigators suspect that it could have resulted from an
explosion of fuel vapors that built up in the center fuel
tank, possibly sparked by the plane's electrical wiring.
In November, the FAA ordered airlines to install new
equipment to shield wiring around fuel pumps in 747s.