Some excerpts from a synopsis of the NTSB's final report published at a hearing today, subject to editing.
Executive Summary
On July 7, 2017, about 2356 Pacific daylight time (PDT), Air Canada flight 759, an Airbus A320-211, Canadian registration C-FKCK, was cleared to land on runway 28R at San Francisco International Airport (SFO), San Francisco, California, but instead lined up with parallel taxiway C.1 Four air carrier airplanes (a Boeing 787, an Airbus A340, another Boeing 787, and a Boeing 737) were on taxiway C awaiting clearance to take off from runway 28R. The incident airplane descended to an altitude of 100 ft above ground level and overflew the first airplane on the taxiway. The incident flight crew initiated a go-around, and the airplane reached a minimum altitude of about 60 ft and overflew the second airplane on the taxiway before starting to climb. None of the 5 flight crewmembers and 135 passengers aboard the incident airplane were injured, and the incident airplane was not damaged. The incident flight was operated by Air Canada under Title 14 Code of Federal Regulations (CFR) Part 129 as an international scheduled passenger flight from Toronto/Lester B. Pearson International Airport, Toronto, Canada. An instrument flight rules flight plan had been filed. Night visual meteorological conditions prevailed at the time of the incident.
The flight crewmembers had recent experience flying into SFO at night and were likely expecting SFO to be in its usual configuration; however, on the night of the incident, SFO parallel runway 28L was scheduled to be closed at 2300. The flight crew had opportunities before beginning the approach to learn about the runway 28L closure. The first opportunity occurred before the flight when the crewmembers received the flight release, which included a notice to airmen (NOTAM) about the runway 28L closure. However, the first officer stated that he could not recall reviewing the specific NOTAM that addressed the runway closure. The captain stated that he saw the runway closure information, but his actions (as the pilot flying) in aligning the airplane with taxiway C instead of runway 28R demonstrated that he did not recall that information when it was needed. The second opportunity occurred in flight when the crewmembers reviewed automatic terminal information system (ATIS) information Quebec (via the airplane’s aircraft communication addressing and reporting system [ACARS]), which also included NOTAM information about the runway 28L closure. Both crewmembers recalled reviewing ATIS information Quebec but could not recall reviewing the specific NOTAM that described the runway closure.
The procedures for the approach to runway 28R required the first officer (as the pilot monitoring) to manually tune the instrument landing system (ILS) frequency for runway 28R, which would provide backup lateral guidance (via the localizer) during the approach to supplement the visual approach procedures. However, when the first officer set up the approach, he missed the step to manually tune the ILS frequency. The captain was required to review and verify all programming by the first officer but did not notice that the ILS frequency had not been entered.
The captain stated that, as the airplane approached the airport, he thought that he saw runway lights for runway 28L and thus believed that runway 28R was runway 28L and that taxiway C was runway 28R. At that time, the first officer was focusing inside the cockpit because he was programming the missed approach altitude and heading (in case a missed approach was necessary) and was setting (per the captain’s instruction) the runway heading, which reduced his opportunity to effectively monitor the approach. The captain asked the first officer to contact the controller to confirm that the runway was clear, at which time the first officer looked up. By that point, the airplane was lined up with taxiway C, but the first officer presumed that the airplane was aligned with runway 28R due, in part, to his expectation that the captain would align the airplane with the intended landing runway.
The controller confirmed that runway 28R was clear, but the flight crewmembers were unable to reconcile their confusion about the perceived lights on the runway (which were lights from airplanes on taxiway C) with the controller’s assurance that the runway was clear. Neither flight crewmember recognized that the airplane was not aligned with the intended landing runway until the airplane was over the airport surface, at which time the flight crew initiated a low-altitude go-around. According to the captain, the first officer called for a go-around at the same time as the captain initiated the maneuver, thereby preventing a collision between the incident airplane and one or more airplanes on the taxiway. However, at that point, safety margins were severely reduced given the incident airplane’s proximity to the ground before the airplane began climbing and the minimal distance between the incident airplane and the airplanes on taxiway C.
The flight crewmembers stated, during postincident interviews, that the taxiway C surface resembled a runway. Although multiple cues were available to the flight crew to distinguish runway 28R from taxiway C (such as the green centerline lights and flashing yellow guard lights on the taxiway), sufficient cues also existed to confirm the crew’s expectation that the airplane was aligned with the intended landing runway (such as the general outline of airplane lights—in a straight line—on taxiway C and the presence of runway and approach lights on runway 28R, which would also have been present on runway 28L when open). As a result, once the airplane was aligned with what the flight crewmembers thought was the correct landing surface, they were likely not strongly considering contradictory information. The cues available to the flight crew to indicate that the airplane was aligned with a taxiway did not overcome the crew’s belief, as a result of expectation bias, that the taxiway was the intended landing runway.
The flight crewmembers reported that they started to feel tired just after they navigated through an area of thunderstorms, which radar data indicated was about 2145 (0045 eastern daylight time [EDT]). The incident occurred about 2356, which was 0256 EDT according to the flight crew’s normal body clock time; thus, part of the incident flight occurred during a time when the flight crew would normally have been asleep (according to postincident interviews) and at a time that approximates the start of the human circadian low period described in Air Canada’s fatigue information (in this case, 0300 to 0500 EDT). In addition, at the time of the incident, the captain had been awake for more than 19 hours, and the first officer had been awake for more than 12 hours. Thus, the captain and the first officer were fatigued during the incident flight.
Cockpit voice recorder (CVR) information was not available for this incident because the data were overwritten before senior Air Canada officials became aware of the severity of this incident. Although the National Transportation Safety Board (NTSB) identified significant safety issues during our investigation into this incident, CVR information, if it had been available, could have provided direct evidence about the events leading to the overflight and the go-around. For example, several crew actions/inactions during the incident flight demonstrated breakdowns in crew resource management (CRM), including both pilots’ failure to assimilate the runway 28L closure information included in the ATIS information, the first officer’s failure to manually tune the ILS frequency, and the captain’s failure to verify the tuning of the ILS frequency. However, without CVR information, the NTSB could not determine whether distraction, workload, and/or other factors contributed to these failures.