(CNN) -- A Chautauqua Airlines pilot was kept off a flight in Omaha, Nebraska, Thursday morning after he failed a blood-alcohol test, a spokeswoman for the Federal Aviation Administration said.
Authorities said they were tipped off by a hotel shuttle bus driver, who called airport police to report he suspected the pilot was drunk.
FAA spokeswoman Elizabeth Isham Cory said the agency is investigating the incident.
The male pilot, whose identity was not released, was scheduled to fly Frontier Flight 1894 from Omaha to Milwaukee at 6 a.m., according to the airline. Both Chautauqua and Frontier are owned by Republic Airways Holdings, Inc.
But shortly before the flight, a shuttle bus driver called the Eppley Airfield Airport Police to report his concerns about the pilot, said Chris Martin, director of operations for the Omaha Airport Authority.
"The pilot did make it through the checkpoint and he was met by our police officers near the gate of departure," Martin said.
Airport police talked to the pilot and handed the investigation over to Frontier Airlines, as well as notifying the FAA, Martin said.
Under the FAA's so-called "bottle-to-throttle" rule, pilots are prohibited from flying or performing any safety-sensitive operation within eight hours of consuming alcohol, or if they have a blood-alcohol concentration of 0.04 percent or higher. But Frontier Airlines spokeswoman Lindsey Carpenter said Frontier and Chautauqua enforce policies that are even more strict than the FAA's eight-hour rule.
The airline said 29 passengers and a three-person crew were on Flight 1984, an Embraer 145 aircraft.
"Because this is a personnel issue, we can't and won't comment on specifics other than to say that because of concern for the condition of the crew member, the crew member was replaced," Carpenter said. "Frontier and Chautauqua have a zero-tolerance policy for drugs and alcohol that has resulted in a 100% safety record for both carriers."
"Appropriate action will be taken with the crew member when our investigation is complete," she said.