The NTSB has found a new focus for its investigation into TWA Flight 800 -
 lavatory waste.

 There is no longer any doubt that the NTSB determination of probable cause
 for TWA 800's explosion is going to be faulty wiring.  Exacerbated by
 "galley fluids" and leaky toilets perhaps.

 Two Reuters articles follow:

 Focus of TWA 800 crash on wiring - NTSB

 WASHINGTON, Sept 14 (Reuters) - National Transportation Safety Board (NTSB)
 investigators are focusing on possible sparking from aging wires as the
 cause of the 1996 TWA Flight 800 crash off Long Island that killed all 230
 people on board.

 James Hall, chairman of the NTSB, told NBC's Today Show that testing of
 wiring bundles in 25 different planes has focused U.S. aviation officials'
 attention on Boeing 747's electrical system as a possible cause of the

 "We are now looking very closely at possible electrical discharges that may
 have come off of some of that wiring that could have caused the accident
 itself,'' Hall said.

 NTSB investigators have long suspected that fumes in the plane's center fuel
 tank were ignited by some sort of electrical fault.

 Hall was speaking from Calverton, Long Island, where the reconstructed
 wreckage of TWA 800 was being moved to a smaller hangar Tuesday.

 On Monday, USA Today reported that the private laboratory hired by the NTSB
 to test Poly-X wiring -- the same type used in the destroyed TWA 747
 aircraft -- found that it sparked more than expected when bundles of it were

 Wet-testing simulates what might happen when cracked insulation on
 electrical wires is exposed to salt water or waste water from an airplane's
 galley or restrooms.

 For his part, NTSB chairman Hall refused to confirm those results during his
 NBC News interview, deferring any comment until the safety board's final
 report is released.

 That report is expected early next year.

 U.S. panel told all aircraft wiring ages, cracks

 By Tim Dobbyn

 WASHINGTON, Sept 15 (Reuters) - All aircraft wiring ages, and it is not
 uncommon to find five to 10 insulation cracks per 1,000 feet of wire in
 active aircraft, a congressional subcommittee heard Wednesday.

 Armin Bruning, an engineer who heads a company that has done testing for the
 National Transportation Safety Board, said the plastics insulating wire all
 aged, leading to problems ranging from minor troubles with instruments to
 fires and sometimes deaths.

 Wiring is becoming one of aviation's hottest safety topics, with a suspected
 role in two high-profile crashes in the last four years. There has also been
 increased research into the problem.

 A Federal Aviation Administration official told a hearing of the House
 Transportation subcommittee that the so-called aging aircraft fleet would
 soon include heavily electronics-reliant aircraft of the 1980s such as the
 Boeing 757 and 767 and the Airbus A-300.

 "The FAA and, indeed, the entire aviation industry are only now beginning to
 have a greater appreciation and understanding about the need to examine
 nonstructural aspects of our aircraft,'' FAA Associate Administrator Tom
 McSweeny said.

 Bruning, president of Lectromechanical Design Co., a Dulles, Virginia,
 concern that has worked with the U.S. Navy, said humidity, high temperatures
 and strain all contributed to wire aging.

 Although not all insulation breaks lead to sparks or accidents, it is best
 to minimize the problem, he said.


 NTSB aviation safety director Bernard Loeb said the board's attention had
 been focused by two major crashes: the 1996 explosion of a TWA jumbo jet off
 Long Island, which killed all 230 people on board, and last year's Swissair
 MD-11 crash off Canada's Nova Scotia coast, which killed the 229 people it

 Safety investigators suspect that an electrical fault, possibly in the fuel
 measuring system, ignited fumes in the center fuel tank of TWA Flight 800.

 In the Canadian crash, attention has focused on damaged wires in the ceiling
 of the cockpit.

 Loeb said inspections of more than 25 other aircraft after TWA 800 found
 wiring problems in all cases, ranging from lint and metal shavings on wire
 bundles to cracks in insulation.

 The NTSB is following up with tests in which wire bundles contaminated with
 metal drill shavings are vibrated.

 It was recently reported that another series of tests documenting the arcing
 potential of TWA 800-type wire when contaminated with galley fluids and
 lavatory waste showed surprisingly violent reactions.

 Loeb said outside the hearing that the NTSB was also planning to use an
 operating Boeing 747 to check the effect of turning powerful electrical
 circuits on and off and the induction of strong currents into adjacent
 low-voltage wires.

 Under one scenario, excessive electrical energy may have entered TWA 800's
 fuel tank through the normally low-voltage fuel measuring system.

 "The safety board is concerned that industry and regulatory efforts have
 been relatively ineffective in preventing the types of wiring hazards seen
 during the TWA Flight 800 investigation,'' Loeb testified.