Peter Parsons / Herald Photo Don Enns, an investigator with the Transportation Safety Board of Canada, looks over the landing-gear section of Swissair Flight 111 at CFB Shearwater on Thursday.

By Lois Legge / Staff Reporter

It looks like a massive autobody shop. Metal cylinders, tangled air ducts, damaged valves and fuel pumps lie atop plywood tables.

Wiring in all sizes and colours sits in a large box or hangs from frames.

But the engineers and investigators inside Hangar A at Canadian Forces Base Shearwater have a job much more complicated than assembling car parts.

And their ultimate goal is to find out why 229 people died.

For months, they've been sifting through the remnants of Swissair Flight 111, the Boeing MD-11 that crashed off Nova Scotia on Sept.2, killing all passengers and crew aboard and shattering the aircraft into more than a million pieces.

Vic Gerden, chief investigator for the Transportation Safety Board of Canada, and his colleagues showed reporters Thursday how they are trying to connect those pieces to solve the puzzle and prevent a future disaster.

Mr. Gerden revealed little new information Thursday about what may have caused the crash, but he and fellow investigators made one thing clear - their job in an already $62-million investigation is far from over.

The probe is zeroing in on what caused smoke in the cockpit 16 minutes before the plane plunged into St. Margarets Bay.

In HangarA, investigators are reconstructing sections of the front part of the plane, vital to solving the mystery because that's where the heat damage is concentrated. Temperatures there reached some 600 C.

A nine-metre metal frame - a full-scale mockup of the area extending back from the cockpit to the beginning of the first-class section - already includes some pieces of the plane.

A large section of fuselage has been attached to one side, five windows clearly visible.

Inside the frame, reconstructed wiring, air ducts and other pieces have been tied to the jig.

Yet more pieces of the forward section - the main cockpit instruments; three galleys, one with clearly visible heat damage on the ceiling; and wires - have been assembled on the floor or on tables in the hangar.

"We are using the frame as a tool to assess the origin of the heat," Mr. Gerden said.

But the task is extremely difficult because many of the pieces are so tiny that investigators must first discover what they are and where they belong.

So far, they've found 13 wires - out of 250 kilometres of wiring aboard the MD-11 - that show signs of arc-tracking, which occurs when insulation covering wire bundles breaks down. Arc-tracking can spark a massive fire along the rest of the wires.

Seven of the arced wires came from the plane's high-tech inflight entertainment system.

But whether wiring actually caused a fire aboard Flight 111 still isn't clear.

"We still do not have an analysis ... of whether the arcing was the origin of the fire or whether there was a fire that damaged the wires, therefore removing insulation which caused the arcing," Mr. Gerden said.

Investigators hope to find more damaged wiring among the 11 per cent of the aircraft still underwater. Of the wires found so far, many were broken apart by the devastating impact of the nose-first crash.

Standing next to a box of wiring, investigator Jim Foot holds up an arc-damaged piece a little longer than his index finger.

"When you start off with a box of wire like this, this is the needle in the haystack," he said.

Mr. Gerden said investigators are using every tool at their disposable, from virtual reality-type computer mockups to heat tests that show what charring by the most intense heat looks like.

Most of the 89 per cent of the jet recovered - totalling 115,000 kilograms - sits elsewhere.

Larger pieces without heat damage, including the MD-11's mangled landing gear, wings and pieces of fuselage, are stored in an open compound next to Hangar J. Inside, three large engines accompany 650 boxes containing everything from carpeting to bits of fuselage.

Reminders of the vast human tragedy are found in simple words marked in cardboard: Life Rafts and Survival Kits, items the passengers never got to use.