This is an illuminating look at the tragic crash of Swissair 111 in 1998 and the extremely difficult and years-long investigation to pinpoint the cause of the disaster. Perhaps even more importantly, the context of this fully avoidable accident casts a bright and extremely worrisome light on the continuing failures that pervade the air traffic industry.

It is a story that goes beyond the tombstone mentality of aircraft makers and airlines executives and reveals the unwillingness and/or inability of the Federal Aviation Administration to ensure the safety of the millions of air passengers every year. This excellent documentary should and almost surely will make you angry.

On Sept. 2, 1998, Swissair Flight 111 bound from New York to Geneva crashed off the coast of Nova Scotia, killing all 229 people on board. With the plane literally destroyed on impact, its debris lying 180 feet underwater, investigators had little to go on. The crew had reported a transient smell of smoke in the cockpit that seemingly disappeared when an air conditioning vent was closed -- only to return in a significant way minutes later. A non-urgent emergency was declared, and the crew began plans to land at Halifax airport -- but only after circling out over the water to dump fuel and begin its descent. It never made it to Halifax.

Investigators soon learned that both the cockpit voice recorder and flight data recorder had failed during the emergency, robbing them of any data for the final six minutes of the flight. Thus began one of the longest, most expensive and most difficult crash investigations in history. This documentary does an excellent job of describing the incredible challenges the investigators faced -- collected and sorting through the tons of tiny debris, testing the wind currents in a similar plane to see how a fire above the cockpit would have spread, analyzing miles of recovered wires looking for evidence of power arcs, recreating the conditions of the flight, mapping every detail of the plane using advanced computer software, etc. Even after determining the cause of the problem, it took many more painstaking months to identify the initial source of the spark that caused the fire.

Investigators made a number of incredibly important discoveries during the investigation, the most important of which was the fact that the insulation around the wiring in the plane's attic was highly flammable. The material had passed FAA tests years earlier, but more stringent testing revealed that this plane and hundreds if not thousands more around the world were basically tinderboxes one good spark away from catching fire. The National Transportation Safety Board was quick to release this information and to recommend this flammable insulation be replaced by more fire-resistant material.

Unfortunately, the NTSB could do no more than recommend such action be taken. Only the FAA has the authority to require safety changes of this type be done. The FAA did enact this recommendation -- but gave airlines years to do it. Thus, this documentary ends on a really ominous note -- at the time of its release in 2004, some six years after the crash of Swissair 111, hundreds of planes worldwide were still flying daily with highly flammable insulation protecting the wiring. Not only that, we learn that Boeing and the FAA knew about the insulation issue long before Swissair 111's last flight, which means its 229 passengers and crew should never have died in the first place.

As a viewer, this widespread tendency of airline companies and aircraft manufacturers to ignore huge safety issues until it leads to needless death and destruction infuriates me. Time after time, we also see that the FAA is complicit in what should really be prosecuted as criminal negligence. I should note that this documentary doesn't make this final point, but anyone who looks into the history of air disasters over the past few decades will find ample evidence of the industry's failure to correct known problems until hundreds of people die. I would hope that as many people as possible view this eye-opening documentary for themselves.