WHEN THE CABIN of Air Canada Flight 797 began to fill with heavy, black smoke, my husband Randy and I were sitting in seats 12D and 12E, over the right wing.

I will never forget the feeling of sheer terror. I still have nightmares remembering that day in June 1983.

Randy and I both thought we might die. But we knew we were sitting by an exit, and we were determined to stay put until we could use that exit. This decision saved our lives, because we knew where the exit was and didn't have to see to get out.

The smoke got worse as the minutes ticked by. By the time we landed at Greater Cincinnati International Airport, about 10 minutes after the fire broke out, the smoke was so bad I couldn't see Randy sitting in the seat next to me. I couldn't even see my hand in front of my face.

Crew members instructed the passengers to move forward in the plane in an apparent effort to speed evacuation of the jet once we landed. I believe the Air Canada crew did everything it could to minimize the tragedy. That the pilot was able to land safely at all is vitually miraculous.

But the hard fact is that while 18 passengers and five crew members survived, 23 passengers needlessly died. I remember thinking at the time, "They just couldn't see. They just couldn't see their way out of the plane."

Randy and I were fortunate. We were sitting very close to the emergency door, and he was able to open it. We crawled out on the wing and several others followed us out. But even outside the smoke was so thick we couldn't see the ground. We jumped to safety after flames came out the door.

I HAVE BECOME a strong believer in improved passenger safety on all commercial airliners.

One improvement appears to be the requirement that aircraft be equipped with fire retardant materials.

Another is that the Federal Aviation Administration will require airlines to install escape lights or marking systems near the floor where the smoke is theoretically less dense -- and where the exit lights are most apt to be visible. These must be installed on commercial airliners by November 1986.

Although these new evacuation regulations are well-intentioned, they just don't go far enough to require that the airlines install systems that actually will work -- that will get people out of smoke-filled aircraft cabins.

The regulations do not actually require the airlines to demonstrate that the system they adopt can even be seen in dense smoke. The regulations also assume that there won't be any smoke at all below four feet. That wasn't the case on the Air Canada flight. At one point, a flight attendant sat on the floor near the front seats. She reported later that the smoke was so dense that she could see only the knees of the passenger in front of her.

Recently I participated in a demonstration comparing several emergency lighting systems at the Federal Aviation Administration's Civil Aeromedical Institute in Oklahoma City. These systems included radioactive tritium strips that glow in the dark, spotlights, strobe lights, fluorescent lights recessed under the seats and a system of incandescent lights -- developed by George Plumly, an inventor in Fort Worth, Tex. -- in which lights are placed just under the seats on both sides of the airplane's carpet.

After the plane was filled with test smoke -- and smoked several times -- the smoke was almost as dense as Randy and I experienced on that Air Canada flight. Here's what the demonstration proved to me:

The tritium strips were virtually impossible to see, even when I knew where they were located.

The spotlights placed at the exits didn't help much, mainly because the source of the light was not visible the light they produced cannot be seen in smoke.

The fluorescent lights under the seats were practically worthless in defining the escape route.

The strobe lights were just confusing.

The floor lights developed by Plumly were bright and clearly indicated where the aisle was and where all the exits were, including the front galley exit which normally isn't used because nobody knows it's there.

I'm sure other lighting companies could develop a system that would be as effective as the one developed by Plumly. I can't prove that all 23 passengers would have survived if Plumly's system or one as effective had been installed on the Air Canada DC-9, but I do know they would have had a much better chance.

I would be surprised if the airlines installed any safety system that wasn't absolutely required by the Federal Aviation Administration.

I don't understand how systems that clearly don't work -- although they might technically meet the regulations -- could be approved by the Federal Aviation Administration. And I don't understand why airlines would even want to install a system just to meet regulations that are demonstrably weak, and that the airlines themselves admit won't work. They ought to be concerned with solving the problem, not just satisfied to take the cheapest way out.

Airlines spend millions of dollars every year to attract passengers. One airline is boasting about spending $15 million to make the seats approximately one inch wider. Another airline is installing headphones that allow passengers to listen to music as they walk up and down the aisle.

Certainly the airline business is competitive, and wider seats or wireless headphones might help attract passengers. But passenger safety ought to take a higher priority than passenger amenities.

I've kept in close contact with other people who are knowledgeable about the issue. I asked what it would cost to install a system like Plumly's on commercial airlines. Would it be 10 percent of the cost of the airplane? Five percent? One percent? I was astounded to learn it would only cost 39/100,000ths of the cost of the plane -- less than $7,000 per plane (or $21 million for the domestic airline industry's entire fleet of 3,000 planes).

Even so, people who are following the issue say the airlines appear to be leaning toward spotlights at the exits -- despite the FAA's own demonstrations' proving that they won't work: They can't be seen in smoke.

Statistically, flying is one of the safest ways to travel, and the safety record of the airlines is impressive. But statistics are meaningless the moment you find yourself in a smoke-filled jet wondering whether you'll live or die.

If the regulations regarding emergency evacuation lighting are truly as weak as they appear to be, the FAA ought to scrap them and start all over again. At the very least, the FAA ought to rewrite the new regulations to ensure that the airlines do adopt emergency evacuation lighting systems that will get people out of smoke-filled airplanes.

The Air Canada disaster should be the catalyst for realistic, effective emergency lighting regulations.

Otherwise, those 23 people who didn't make it out of that terrifying smoke because they couldn't see died in vain.