The American Eagle flight from O’Hare Airport to Sioux City was climbing out of Chicago when the crew levelled off and decided to return to the airport, to pick up a passenger that had missed the flight.
The Embraer ERJ-145 aircraft needed to return to Chicago to pick up a pilot, who had indeed really been left behind at departure.
An American Eagle spokesman later reported that one of the pilots on the flight would have exceeded his permitted flying hours for the return sector, therefore another pilot had been rostered on for that part of the journey, he was meant to travel to Sioux City as a passenger but arrived late to the gate and the plane left without him.
The company decided to have the aircraft return to Chicago in orfer that it have the correct crew to perform the return flight, otherwise the aircraft would have been stranded in Sioux City.
The aircraft reached Sioux City with a delay of just over 2 hours. The possibly embarrased missing pilot was not available for comment.
So for the sector concerned, the pilot was just another SLF.