The National Transportation Board tells KING 5 News that it will investigate a case where an Air Canada A320 airliner mistakenly took a taxiway for the runway in San Francisco - a taxiway occupied with four other jetliners awaiting their turn to take off.

And it also appears the planes came much closer together than first thought, as little as 100 feet.

NTSB spokesman Keith Holloway says an investigator who is an expert in airline operations will be going out to look at the circumstances last Friday night that led the pilots of the Canadian Airbus to line up with the taxiway instead of runway 28R.

According to the Daily Notification Log from the Transportation Safety Board of Canada, information gathered from U.S. authorities indicate the Air Canada jet was just 100 feet above the first jet, 200 feet over the third one and 300 feet over the fourth jet on the ground.

The plane was able to make another approach and land without further incident.