By Robert Herguth
The pilots of a United Airlines plane that slid off the end of an O’Hare Airport runway last December had been awake for 23 hours or more and had spoken of feeling “fatigued” even before departing Seattle for Chicago with more than 160 passengers on board, newly obtained Federal Aviation Administration records show.
The pilots of the Boeing 737 also thought they were landing on a different, longer runway at O’Hare and might have made a series of braking errors while trying to bring the jetliner to a stop on a landing strip “obscured by snow,” according to a two-page FAA document.
The paperwork — released by the federal agency in response to a public records request — doesn’t cite a cause for the runway “overrun,” which United says could be the result of a number of factors, including “runway conditions.”
“It is a very small piece of a larger investigation,” FAA spokeswoman Elizabeth Isham Cory says, describing the document as “non-decisional.”
The FAA says the incident, which didn’t result in any injuries or major damage to the plane, remains under investigation.
The incident was one of three similar overruns at O’Hare on the same runway last winter. There have been at least nine “excursions” from O’Hare runways and taxiways since 2010, city records show.
It was a snowy morning, with temperatures in the 20s, when United Flight 1977 touched down on Runway 9 Left/27 Right a little after 7:30 a.m. Dec. 30. The runway, which stretches 7,500 feet, opened in 2008 as part of O’Hare’s ongoing expansion and reconfiguration.
An FAA air-traffic controller had cleared the United jetliner for landing and said “braking action” was reported as “good” — meaning not too slippery, according to a copy of radio transmissions.
But soon one of the pilots reported, “Be advised, braking action was nil” — meaning the jet’s tires weren’t catching on the pavement very well.
The aircraft slid off the end of the runway, according to records from Mayor Rahm Emanuel’s city Department of Aviation, which operates O’Hare and Midway airports.
City crews had been standing by to conduct a “friction” test and, if necessary, clear snow and ice.
The FAA record says the captain of Flight 1977 was awake for 25 hours “at the time of the incident,” and the first officer — the second pilot — had been awake for 23 hours.
“Crew discussed being fatigued at length prior to departure from [Seattle] but felt compelled to complete the mission,” the document says. “Crew discussed napping as a fatigue-mitigation strategy en route.”
Also, according to the FAA document:
• The pilots “thought they were landing on the longer of the parallels [runways] but in fact were landing on the shorter.”
• The pilots might have “inadvertently selected” a less-powerful brake setting and did not account for the runway being “obscured by snow.”
• “Despite being fatigued, [the] Captain decided to hand fly” the plane from 10,000 feet to arrival, rather than rely on the autopilot.
The FAA requires pilots to have a “10-hour minimum rest period prior to the flight duty period,” with “an opportunity for eight hours of uninterrupted sleep within the 10-hour rest period.”
“Rest” doesn’t have to mean “sleep,” though, aviation experts say, and an “opportunity” for sleep also doesn’t necessarily mean actual snoozing.
FAA rules put great responsibility on pilots to not fly if they’re overly tired, according to Embry-Riddle Aeronautical University’s Bill Waldock, a pilot who created the university’s aviation safety programs and teaches accident investigation.
Before takeoff, pilots “have to positively affirm that they are fit for duty,” Waldock says.
The FAA document doesn’t say what rest the United pilots got. But it does say that one or both of the United pilots “will receive” training in, among other things, “cold-weather ops” and “fatigue risk management.”
United spokesman Charles Hobart declined to discuss that. He would say only that the airline is still conducting its own “internal review” and that “there may be other contributing factors involved,” including “possible runway conditions,” the weather and air-traffic control.
Chicago Aviation Commissioner Ginger Evans wouldn’t comment.
Robert Herguth is an investigator for the Better Government Association.