ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, May 20, 1996 TAG: 9605200153
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: THE WASHINGTON POST
Investigators combing the wreckage of ValuJet Flight 592 said Sunday that they had found pieces of hazardous oxygen-producing canisters imbedded in a fire-damaged tire that had been in the cargo hold. They also found the first evidence of thick smoke that was in the passenger cabin before the DC-9 crashed May 11 with 110 people aboard.
They also indicated that as many as 119 fully charged canisters could have been loaded on the plane haphazardly and without the safety caps that are supposed to be on their firing mechanisms.
The canisters contain a chemical that generates oxygen under high heat. If accidentally discharged, each canister is capable of producing sustained external heat of 500 degrees.
Greg Feith, investigator in charge for the National Transportation Safety Board, refused to speculate on a cause of the DC-9's crash into Florida's Everglades, saying his investigators are ``not going to stop and shift their entire effort to the cargo hold and these oxygen canisters.''
However, facts laid out by Feith at a news conference near the crash scene raise the possibility that the canisters somehow fell, ignited and started a smoky fire among the tires that were in the same hold. The canisters not only had no firing pin protection, but were mislabeled ``empty'' rather than ``hazardous material.''
Several of the boxes holding the canisters were placed loose in the cargo hold on top of the tires. The smoke, and possibly fire, eventually could have worked its way into the cockpit and passenger cabin.
Two aviation sources said when the safety cap is off, the canisters have a hair trigger, requiring only a pound of force to detonate.
National Transportation Safety Board Vice Chairman Robert Francis said on CNN's Late Edition, ``There are lots of other things that can cause fires on airplanes,'' but oxygen generators are ``high on the list in terms of what we are interested in finding'' and checking.
Investigators previously had identified possible smoke and fire damage in the cockpit.
Now they know there was smoke in the cargo hold and in the passenger cabin, where a 6-inch piece of railing in which passenger seats are anchored was found with ``heavy sooting patterns on it.''
The NTSB's Feith said the tire was a key discovery. Wreckage stuck in the tire ``leads us to believe this was a tire in the cargo hold. That tire does bear evidence of fire damage, heat damage.''
When fire experts ``were cleaning out the mud that was inside the tire, they did find two pieces of metal that they have been able to identify are end caps to these oxygen generators,'' Feith said. ``We believe they are two separate end caps for two separate oxygen generators.
``These end caps do have evidence of heat on them, or very high heat signatures. We also found a part of a firing mechanism, one of the support mechanism that holds a charge that actually sets off these canisters when pulled.''
A finding that a hot, oxygen-fed fire in the cargo hold caused the crash would almost certainly resurrect recommendations to the Federal Aviation Administration for fire detection systems and automatic fire extinguishers in aircraft holds.
The FAA has resisted such systems in favor of fire-retardant liners. However, the requirements for the cargo hold liners do not take into account the effect that hazardous materials could have in feeding the severity of a fire.
The safety board has recommended several times that cargo holds be fitted with better fire safety apparatus. The last such recommendation came in 1993 after the probe of a 1988 in-flight fire. American Airlines Flight 132 landed at Nashville with smoke in the cabin and a hot floor that required passengers to move. The fire was extinguished after the landing. Investigators found illegally shipped textile treatment chemicals in the hold.
Responding to that recommendation, the FAA said new fire extinguisher systems would be too costly and would not have protected against a super-hot fire from ``the illegal shipment of powerful oxidizers.''
The oxygen canisters aboard Flight 592 are used on some aircraft - not the DC-9 - to feed oxygen to passenger masks in an emergency. When passengers pull the masks down, a firing pin ignites sodium chlorate inside the canister, which produces oxygen as it burns. Above passenger seats, the canisters are well insulated.
At least three times before when they were loaded as cargo, such canisters have caused aircraft fires, including one in 1986 in Chicago that destroyed a DC-10. Aviation sources also said there were less serious incidents - in Oakland in 1992 and San Francisco in 1993 - in which damage was confined to single cargo containers of Qantas Airlines and Federal Express.
Feith said a Miami aircraft repair facility, Sabre Tech, removed the expired canisters from three ValuJet MD-80 aircraft two to three months ago and stored them in cardboard boxes. At some point, a Sabre Tech official discovered the boxes of generators and ordered them returned to ValuJet.
``It is our understanding that in the process of trying to account for inventory and that kind of thing in a storage room, these passenger service units ... and some tires ... were being sent back to ValuJet since they were ValuJet's property,'' Feith said.
Sabre Tech then delivered the boxes to ValuJet at the Miami airport, where an airline employee told the Sabre Tech employee to leave them on a baggage cart. The baggage crew loaded them. The boxes were marked as company material - not hazardous material - and the manifest said they were empty.
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