SEATTLE -- Both the FAA and Alaska Airlines have launched investigations after a plane accidentally landed on a taxiway instead of a runway at Sea-Tac International Airport earlier this month.

While nobody was hurt in the incident at Sea-Tac, had another plane been parked on the taxiway, the results could have been catastrophic.

A few minutes before landing at about 8:30 a.m. on December 19th, the air traffic control tower offered up runway 16 Center to Alaska Flight 27. The flight was originally scheduled to land on 16 Right. The crew accepted, but minutes later, the pilot mistakenly landed on the taxiway in-between the runways.

At first glance to those who are not seasoned pilots, it doesn't look too different from the runways at Sea-Tac, but safety experts say for decades the airport has worked to educate pilots to avoid this strip when they land.

"This is not a new problem at Sea-Tac. There have been cases going back to the 1990s of aircraft inadvertently landing on what's called 'taxiway tango,'" said aviation safety expert Dr. Todd Curtis.

Curtis says the landing instructions for Sea-Tac warn pilots about the potential for confusion on taxiways.

"So although this was a dangerous condition, a condition that should be avoided, it's something that can be learned from," said Curtis.

Sea-Tac officials say the last time it happened was in 2004, before the addition of the third runway. They say the markings and size of the taxiway are different than those of the actual runways, which include distinct markings.

"Even though it doesn't rise to the extent of a full NTSB investigation, this is something that will be investigated and investigated thoroughly," said Curtis.

It's unlikely any of the passengers on board that flight even realized what had occurred, but the FAA is investigating. Alaska Airlines officials say this is not the first time this pilot has landed at Sea-Tac Airport, and they're trying to figure out why a mistake was made.

Curtis says he doesn't believe there is a problem with the layout at Sea-Tac Airport.

Depending on the results of the investigation, the FAA could order Sea-Tac Airport to make changes if they think it's necessary.