SAN FRANCISCO (KGO) -- There was another close call at SFO, this time it involved an Aeromexico plane that was about to land on the wrong runway Tuesday.Aeromexico flight 668 got the okay to land at SFO at around 11:40 Tuesday morning. Based on the recorded interaction between the pilot and air traffic control, everything seemed to be fine.But as the plane was about a mile out, the controller spotted trouble. The FAA says Aeromexico 668 had lined up on the wrong runway.Instead of 2-8 Right, the plane was heading to the runway next to it, 2-8 Left -- and on it was a Virgin America flight filled with passengers.The FAA says the pilots were using a guidance system often used in poor weather to help with their approach.The pilots will be interviewed as part of the investigation."The runways at San Francisco International are fairly unique because they're very close together," said ABC aviation expert John Nance. "That also means that visually, you can kind of get mixed up a little more easily than you could if the runways were a mile from the other one laterally."This is the second close call at SFO in recent months. In July, an Air Canada flight mistook a crowded taxiway for 2-8 Right. The plane flew as low as 59 feet off the ground before the pilot aborted the landing."All the flight operations in and out, it's not exactly outside the realm of expectation," said Nance.As for Aeromexico, the airline has yet to respond to our request for comment.