Was Swissair Crash Preventable?

While the cause of the fatal crash of Swissair Flight 111 remains a mystery, investigators do know that the pilot's call for an emergency landing was triggered by smoke in the cockpit.

Now it seems that a new technology could have made it easier for the pilot to see through the dense smoke and possibly land the plane safely, but many airlines don't use it, reports CBS News Correspondent Roberta Baskin.

Swissair had a problem with smoke in the cockpit before, and later sought a solution. In 1970, 47 people were killed in a crash after the Swissair pilot radioed that he could not see his instrument panels because of thick smoke.

Seven years ago, Swissair made plans to be the first commercial airline to try a more effective approach to dealing with smoke in the cockpit by using the Emergency Vision Assurance System (EVAS).

The $20,000-per-plane system was designed to work in a smoke emergency. The pilot puts on special goggle/helmet gear that resembles a see-through bubble. The EVAS gives the pilot clear vision to the instrument panel, even through heavy smoke.

In a 1991 industry journal, Swissair's own flight safety manager announced, "Smoke-related accidents may be preventable."

CBS This Morning obtained a Swissair correspondence from 1992 stating: "Swissair intends to procure the EVAS for its entire fleet."

However, following the 1996 Valujet accident, David Hinson, who was then head of the Federal Aviation Administration, went to Capitol Hill and reassured senators that current aircraft ventilation systems were sufficient.

"A manufacturer has to demonstrate we can evacuate the air from the cabin of a plane in a fairly orderly fashion to rid the cabin of smoke and fumes," Hinson said.

However, critics of the FAA's current smoke in the cockpit test say it's not very realistic.

To test the system, a machine fills up the cockpit with smoke until the instruments are no longer visible. Then the smoke machine is turned off, and the ventilation is turned on and has three minutes to clear out enough smoke so the instruments are visible to the pilot.

In a real smoke emergency, at 35,000 feet, there is no one to turn off the smoke machine. In past accidents involving smoke in the cockpit, it's impossible to say what difference the technology might have made.

Even though the FAA has approved and certified the EVAS system for aircraft, it doesn't require it. Within a month of Swissair's announced plans to purchase the system in 1992, it postponed the purchase "due to the difficult situation within the airline industry."

Given the most recent tragedy, CBS News asked Swissair why it never installed the technology.

The company's response: "We purchase our aircraft from manufacturers who comply with all FAA requirements. No manufacturers are currently installing EVAS on commercial aircraft."

Over the weekend, the cockpit voice recorder of Swissair Flight 111 as recovered from the North Atlantic. Under Canadian law, investigators won't release a transcript of the conversation during the last minutes before the crash.

Whatever the actual cause of the crash, the question remains: What role did smoke in the cockpit play in this tragedy? The debate over how best to protect planes, pilots, and passengers may be back on the FAA's radar screen.

Reported by Roberta Baskin