Safety investigators say pilot fatigue was a factor why a FedEx plane landed on the wrong runway after an overnight cargo flight last year.
The National Transportation Safety Board said the pilots failed to recognize cues that they heading for the wrong runway because of fatigue, the early-morning timing and an increased workload.
The safety board, in a report released Thursday, also faulted an an air traffic controller for failing to track the plane after clearing the pilots to land at Tulsa International Airport in Oklahoma. The controller missed the chance to tell the pilots they were off-course, the NTSB said.
Fatigue has long been a concern of safety advocates, and there are federal rules regarding the length of work day and rest rest requirements for pilots. There was no suggestion in the NTSB’s final report that the pilots exceeded those limits during a shift that began in Ontario, California, and included a stop shortly after midnight in Fort Worth, Texas.
FedEx uses something called the Karolinska Sleepiness Scale when setting flight schedules. The scale indicated that the pilots’ schedule that night was just under the threshold for high risk, assuming that they napped between flights.
FedEx, however, didn’t tell pilots they were expected to nap because, a manager told NTSB, the company worried about “overburdening flight crews with additional information.”
The first officer, or co-pilot, slept for 30 minutes after landing in Fort Worth. The captain told investigators he tried to nap but couldn’t. He said, however, that he didn’t feel fatigued.
The NTSB concluded that even though the captain said he wasn’t tired, he was “likely experiencing fatigue due to chronic and acute sleep debt due to limited sleep in the days preceding the incident.” The fatigue — along with a bias against changing a course of action — contributed to the pilots missing cues that they were heading for the wrong runway, including lighting and cockpit displays.
They landed on a parallel strip on the other side of the airfield.
It is rare but potentially catastrophic for airline planes to land on the wrong surface. In 2017, Air Canada pilots who were about to land on a taxiway instead of a runway at San Francisco International Airport came within 10 to 20 feet of crashing into passenger planes lined up on the taxiway.