SAN FRANCISCO (AP) – A top California state official said Wednesday he was a passenger on an Air Canada jet that almost landed on a taxiway where four other planes were sitting rather than the designated runway at San Francisco International Airport.One of the “worst aviation disasters in history” was averted last week when an Air Canada plane was prevented at the last minute from landing into four aircraft on a busy taxiway. An air traffic controller directed the pilot to make another approach and the pilot landed without incident.The 146-seat aircraft just missed the first pair of jets on the taxiway by as little as 100 feet, the third by 200 and the fourth by about 300 feet as it continued to climb, according to CNN, citing a preliminary report from the Transportation Safety Board of Canada.Aviation expert Barry Schiff told the San Francisco Chronicle that a pilot attempting to land on a taxiway rather than a runway is rare because runway lights are always white, particularly clear at night, and are the same around the world. “There is no one on 28-Right but you”.It appears that the runway Air Canada thought it was lining up to land on was not the runway that the air traffic controller was referring to in their communication.The FAA is investigating how close the Air Canada plane – Flight AC759 flying from Toronto to San Francisco – came to the aircraft that were lined up on Taxiway C.The pilot of a United Airlines plane on the ground tells the tower meanwhile that “Air Canada flew directly over us”.Aviation-safety consultant Todd Curtis called the incident “definitely a serious event since a landing on an active taxiway could lead to a catastrophic accident”.”Yeah, I saw that guys”, the tower replies.”We are aware of this incident and are in close contact with the FAA on this”, San Francisco International Airport spokesman Doug Yakel said. “We are still investigating the circumstances and therefore have no additional information to offer”.Runway incidents at takeoff and landing still account for the largest portion of aviation accidents. The newest generation of aircraft now include moving airport maps on their displays to alert the pilot of the aircraft’s position relative to a runway or a taxiway.”OK, Air Canada 759″, the pilot replies.