An American Airlines flight from Detroit to Philadelphia was canceled Saturday after a co-pilot allegedly tested above the blood-alcohol content limit, Bloomberg Business reported.

The pilot, whose name was not revealed, was scheduled to work Flight 736 from Detroit Metropolitan Wayne County Airport to Philadelphia International Airport on Saturday morning. He was detained at a security checkpoint at the Detroit airport in suburban Romulus.

A spokeswoman for American said the airline is helping local law enforcement and the Federal Aviation Administration with its investigation, and that passengers booked on the nixed flight were rebooked.

The legal limit on blood-alcohol content for pilots is 0.04 percent, compared with the 0.08 percent limit for drivers in all 50 states. Pilots are also banned from flying within eight hours of drinking alcohol.

In 2012, an early morning Frontier Airlines flight from Omaha to Milwaukee was delayed two hours after an airport shuttle bus driver reported a pilot he suspected of being drunk to police. A backup pilot was called in, and the flight left later that morning. In January, former Alaska Airlines pilot David Arntson was arrested and charged with flying a common carrier under the influence — a felony — after he tested above the legal limit after flying from Oregon to California in 2014.

And in one of the most notorious intoxicated flying stories, all three members of a Northwest Airlines crew tested over the limit after flying from North Dakota to Minnesota in 1990 — after a suspicious airport bar patron informed authorities. Each of the three served prison time following the incident, but the captain — who had the highest blood-alcohol content of all — was eventually rehired as a flight instructor.

Flight 736 was scheduled to depart Detroit at 6:59 a.m. EDT and land in Philadelphia at 8:47 a.m. The aircraft was an Embraer E-190, a medium-range, narrow-body jet.