An American Airlines pilot was arrested at Detroit Metropolitan Airport on Saturday by airport police after officials say he failed a Breathalyzer test prior to his flight to Philadelphia.

Flight 736, expected to arrive in Philadelphia at 8:47 a.m., was canceled after the Federal Aviation Administration (FAA) detained the co-pilot under the suspicion of having a blood-alcohol level above the legal limit.

Airport spokesman Michael Conway called the situation "extremely unusual," and said the pilot has been released as authorities determine whether charges will be filed. Conway says the pilot is in his early 50s and from Pennsylvania, but declined to release more information.

"We're supposed to be on an airplane and it's supposed to be safe, and you have someone drunk while they're flying the plane," 18-year-old Kendra Hine told Fox2 in Detroit. "That's just crazy."

The FAA prohibits anyone from operating or attempting to operate an aircraft with a blood alcohol content of 0.04 percent or greater, or within eight hours of consuming any alcoholic beverage.

American Airlines spokeswoman Laura Nedbal said in a statement the flight was canceled and customers were transfered to other flights, though some took the opportunity to complain about the situation on social media.

"This is a serious matter, and we are assisting local law enforcement and the Federal Aviation Administration with the investigation," Nedbal said. "We will handle this matter appropriately as the safety and care of our customers and employees is our highest priority."

This is the second incident this month where an American Airlines employee ended up in trouble with law enforcement. Three weeks ago, a flight attendant started a fire in an airplane's lavatory, according to the FBI.