Air Canada 759

• On July 7, 2017, about 2356 Pacific daylight time (PDT), Air Canada flight 759 (ACA759), 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. 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 (agl) 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 (YYZ), Toronto, Canada. An instrument flight rules (IFR) flight plan had been filed. Night visual meteorological conditions (VMC) prevailed at the time of the incident.
• One of the NOTAMs in the dispatch release indicated that runway 28L would be closed from 2300 that night to 0800 the next morning. During postincident interviews, both flight crewmembers provided different accounts regarding their awareness of the runway closure. During interviews about 1 week after the incident, the captain stated that he saw the NOTAM about the runway 28L closure in the flight release, and the first officer stated that he did a “quick scan” of the NOTAMs in the flight release but could not recall whether he had seen the runway 28L closure NOTAM and whether he and the captain had discussed the closure information at the gate. The first officer also stated that he realized, after the incident flight landed, that runway 28L had been closed. During an interview about 1 month after the incident, the captain stated that he and the first officer had discussed the runway 28L closure while at YYZ but that they did not place much emphasis on that information because, at that time, the flight was scheduled to land at SFO before the runway would be closed. (The National Transportation Safety Board [NTSB] notes that the flight was originally scheduled to land at SFO at 2303, 3 minutes after runway 28L was scheduled to be closed.)
• Before the airplane began its descent into the terminal area, the first officer obtained automatic terminal information service (ATIS) information Quebec via the airplane’s aircraft communication addressing and reporting system (ACARS) and printed the information. (Air Canada records indicated that, about 2321, the airplane was sent the ACARS message with the ATIS information.) Among other things, ATIS information Quebec indicated, “Quiet Bridge visual approach in use,” “landing runway 28R,” and “NOTAMS…runways 28L, 10R closed.” (SFO lighting logs indicated that the lights on runway 28L were turned off about 2312.) ATIS information Quebec also indicated that the runway 28L approach lighting system and the runway 28L/10R centerline lights were out of service. During postincident interviews, the flight crewmembers recalled reviewing ATIS information Quebec but could not recall whether they saw the ATIS-reported information about the runway 28L closure.
• ATIS information Quebec also included weather information. Given this information and the reported landing runway in use, the captain briefed Air Canada’s Flight Management System (FMS) Bridge visual approach procedure to SFO runway 28R. The FMS Bridge visual approach to runway 28R, coded as the area navigation (RNAV) 28R approach, was a commercial airline overlay chart (a Jeppesen chart customized for Air Canada) based on the Quiet Bridge visual approach procedure to runway 28R.
• Air Canada’s FMS Bridge visual approach procedure to runway 28R required pilots of Airbus A319/A320/A321 airplanes to manually enter (tune) the instrument landing system (ILS) frequency into the airplane’s flight management computer (FMC) to provide backup lateral guidance (via the localizer) to the runway. The FMS Bridge visual approach to runway 28R was the only approach in Air Canada’s Airbus A320 database that required manual tuning for a navigational aid. As part of his pilot monitoring duties, the first officer would have used the multifunction control and display unit (MCDU) to program required settings, but he did not enter the ILS frequency into the radio/navigation page. The first officer reported, during a postincident interview, that he “must have missed” the radio/navigation page and was unsure how that could have happened. Also, the captain did not verify, during the approach briefing, that the ILS frequency had been entered, and neither flight crewmember noticed that the ILS frequency was not shown on the primary flight displays (PFD). FDR data showed that the ILS frequency was not tuned and that no frequency had been entered.
• As part of the approach briefing, Air Canada’s procedures required the flight crew to discuss any threats associated with the approach. The captain stated that they discussed as threats the nighttime landing, the traffic, and the busy airspace. The captain also reported that he and the first officer discussed that “it was getting late” and that they would need to “keep an eye on each other.” The first officer stated that the threats were the mountainous terrain, the nighttime conditions, and both flight crewmembers’ alertness. The captain and the first officer could not recall whether they discussed the runway 28L closure during the approach briefing.

Source: NTSB AIR, ¶1.1

• According to air traffic control (ATC) voice recordings, at 2330:42, the flight crew checked in with the Northern California terminal radar approach control (NCT) approach controller on the DYAMD 3 (RNAV) standard terminal arrival route to SFO. At that time, the airplane was descending from an altitude of 27,000 ft msl.
• After the flight crew’s initial contact with NCT, the controller issued instructions to join the FMS Bridge visual approach to runway 28R after reaching the final waypoint on the standard terminal arrival route. FDR data showed that, as the airplane descended through an altitude of about 14,500 ft msl at 2336:30, the altitude selected parameter changed to 10,944 ft msl. At 2338:01, the autopilot lateral navigation mode changed from “NAV” to “HDG [heading]” with no recorded corresponding change in the vertical navigation mode. According to Airbus, this configuration and the change in selected altitude were consistent with the autopilot operating in an open descent profile. The flight crewmembers did not discuss the descent mode during the approach briefing, but the first officer reported, during a postincident interview, that he perceived that the descent mode had switched from a managed to an open descent. The first officer also stated that he was uncomfortable with the approach being flown in the open descent mode and that he did not say anything to the captain because the procedure was allowed.

Source: NTSB AIR, ¶1.1

• At 2346:08, the controller instructed ACA759 to turn right direct to the TRDOW waypoint and join the FMS Bridge visual approach to runway 28R, and the flight crew acknowledged this instruction. At 2346:19, the controller asked the crewmembers if they had the airport or bridges in sight; the flight crew replied that the bridges were in sight. At 2346:30, the controller cleared the airplane for the approach and, at 2350:48, instructed the flight crew to contact the SFO air traffic control tower (ATCT).
• At 2351:07, the flight crew contacted the SFO ATCT and advised that the airplane was on the FMS Bridge visual approach to runway 28R. Four seconds later, the tower controller issued a landing clearance for runway 28R. The flight crew acknowledged the landing clearance at 2351:18. FDR data showed that the landing gear was selected to the down position at 2352:46.
• Air Canada’s FMS Bridge visual approach procedure to runway 28R indicated that pilots of Airbus A319/A320/A321 airplanes were to do the following: “at or before F101D [the final waypoint on the approach], disengage autopilot and continue as per Visual Approaches [standard operating procedures].” FDR data showed that the autopilot was disconnected at 2353:28 when the airplane was at an altitude of 1,300 ft and that the flight directors were disengaged at 2354:02 when the airplane was at an altitude of 1,200 ft. The airplane passed F101D at 2354:28, when the airplane was at an altitude of about 1,100 ft, and the captain made the required 14° right turn to align the airplane with runway 28R but instead aligned the airplane with taxiway C.
• During a postincident interview, the first officer reported that, during the approach, he was looking inside the cockpit to accomplish his tasks as the pilot monitoring. For example, after the autopilot was disconnected, the first officer set the missed approach altitude and heading in case a missed approach was necessary; the first officer stated that he had to look at the approach chart to obtain that information. Also, the first officer reported that the captain had asked him to set the heading bug (indicator) to the runway heading. The first officer stated that he had difficulty finding the heading information on the approach chart, so he had to reference the airport chart. The captain reported that he saw lights across what he thought was the runway 28R surface. The captain asked the first officer to find out whether the runway was clear, at which time the first officer looked outside the cockpit. The first officer stated that the captain’s request occurred between the time that the airplane passed F101D (at an altitude of about 1,100 ft) and the time that the airplane descended to an altitude of 600 ft.
• The ATC voice recording indicated that, at 2355:45, the flight crew made the following transmission to the controller: “Just want to confirm, this is Air Canada seven five nine, we see some lights on the runway there, across the runway. Can you confirm we’re cleared to land?” At that time, the airplane was passing through an altitude of 300 ft. During a postincident interview, the controller stated that, just before the query about the status of runway 28R, he had visually scanned the runways from the departure to approach ends. The controller also stated that, in response to the query, he checked the radar display and the airport surface surveillance capability (ASSC) display and then rescanned runway 28R. Regarding the ASSC display, the controller reported that he saw the ACA759 data symbol just to the right of the runway centerline, which he stated was normal for the FMS Bridge visual approach to runway 28R.
• At 2355:52, 1 second after the flight crew completed its transmission, the controller replied, “Air Canada seven five nine confirmed cleared to land runway two eight right. There’s no one on runway two eight right but you.” About that time, the airplane was passing through an altitude of 200 ft and was 2,300 ft (0.38 nautical mile [nm]) from the seawall that protected the airfield from San Francisco Bay. At 2355:58, the flight crew acknowledged the transmission; about that time, the airplane was 500 ft (0.08 nm) from the seawall. Figure 1 shows ACA759’s track before reaching the seawall along with the extended centerlines for runway 28R and taxiway C.

Source: NTSB AIR, ¶1.1

• The ATC voice recording also indicated that, at 2355:59, another pilot stated on the tower frequency, “where is that guy going?” The voice on the transmission was later identified as that of the captain from the first airplane on taxiway C, United Airlines flight 1 (UAL1). About that time, ACA759 was still 500 ft (0.08 nm) from the airport seawall and at an altitude of 150 ft while lined up with taxiway C. At 2356:03 (after ACA759 crossed the seawall), ACA759 overflew UAL1 at an altitude of 100 ft; about the same time, the UAL1 captain stated, over the tower frequency, “he’s on the taxiway.” About the same time as the UAL1 captain’s second transmission, the flight crew from the second airplane on taxiway C, Philippine Airlines flight 115 (PAL115), turned on that airplane’s landing gear and nose lights, illuminating a portion of the taxiway and the UAL1 airplane.

Source: NTSB AIR, ¶1.1

• FDR data showed that, at 2356:05, the throttles on ACA759 were advanced, and the airplane’s engine power and pitch increased. At that time, the airplane was at an altitude of about 89 ft. During a postincident interview, the captain stated that, as the airplane was getting ready to land, “things were not adding up” and it “did not look good,” so he initiated a go-around. The captain reported that he thought that he saw runway lights for runway 28L and believed that runway 28R was runway 28L and that taxiway C was runway 28R. During a postincident interview, the first officer reported that he thought that he saw runway edge lights but that, after the tower controller confirmed that the runway was clear, he then thought that “something was not right”; as a result, the first officer called for a go-around because he could not resolve what he was seeing. The captain further reported that the first officer’s callout occurred simultaneously with the captain’s initiation of the go-around maneuver.
• The airplane continued descending, reaching a minimum altitude of about 60 ft at 2356:07 as the airplane overflew PAL115. One second later, once the engines and elevators had fully transitioned to their go-around position, the airplane began to climb. During the 3 seconds between the time that the flight crew initiated the go-around and the airplane began climbing, ACA759 had flown about 700 ft (0.12 nm) from the location over the taxiway where the go-around was initiated.
• At 2356:09, the controller instructed the ACA759 flight crew to go around. The ACA759 flight crew acknowledged this instruction 2 seconds later as the airplane overflew the third airplane on the taxiway, United Airlines flight 863 (UAL863), at an altitude of 200 ft. Immediately afterward, ACA759 overflew the fourth airplane on the taxiway, United Airlines flight 1118 (UAL1118) at an altitude of 250 ft. Both incident pilots reported (during postincident interviews) that they did not see any airplanes on the taxiway.
• At 2356:12, the controller advised the ACA759 flight crew, “it looks like you were lined up for [taxiway] Charlie,” and instructed ACA759 to fly a heading of 280° and climb to 3,000 ft msl. The flight crew acknowledged the heading and altitude instructions at 2356:18. At 2356:23, ACA759’s landing gear was raised; 5 seconds later, the autopilot was engaged. At 2356:44 and 2356:55, the controller instructed the flight crew to contact NCT, and the crew acknowledged the instruction at 2357:00. During the downwind leg for ACA759’s second approach, the first officer asked the captain if they should set the ILS frequency, and the captain agreed. The second approach to SFO was uneventful, and ACA759 made a successful landing on runway 28R about 0011 on July 8. The captain and first officer completed their duty periods at 0032.

Source: NTSB AIR, ¶1.1

• The airplane that preceded the incident airplane into SFO, a Boeing 737 operated as Delta Air Lines flight 521 (DAL521), landed on runway 28R about 4 minutes before the incident occurred. During postincident interviews, both DAL521 flight crewmembers reported that, after visually acquiring the runway environment, they questioned whether their airplane was lined up for runway 28R. The DAL521 captain stated that he could see lights (but no airplanes) on taxiway C and that those lights gave the impression that the surface could have been a runway. The DAL521 first officer reported seeing a set of lights to the right of runway 28R but that he “could not register” what those lights were. The DAL521 first officer also reported that there were “really bright” white lights on the left side of runway 28R (similar to the type used during construction), but both he and the captain knew that runway 28L was closed.
• The DAL521 flight crewmembers were able to determine that their airplane was lined up for runway 28R after cross-checking the lateral navigation (LNAV) guidance. The DAL521 captain stated that, without lateral guidance, he could understand how the runway 28R and taxiway C surfaces could have been confused because the lights observed on the taxiway were in a straight line and could have been perceived as a centerline. The DAL521 crewmembers confirmed that their airplane was lined up correctly when they visually acquired the painted “28R” marking on the paved surface of the runway; they estimated that their airplane was at an altitude of 300 ft at that time.

Source: NTSB AIR, ¶1.1.1

The airport light status (on/off) and intensity were controlled from the ATCT. Runway 28R was equipped with white runway edge lights, white centerline lights, white touchdown zone lights, and an approach lighting system with white centerline sequenced flashing lights (ALSF-2). Runway 28R was also equipped with a four-light precision approach path indicator with a 3° glidepath that was located on the left side of the runway. Taxiway C was equipped with green centerline lights that were spaced at 50-ft intervals (± 5 ft), blue taxiway edge lights located at the intersections with runway 28R to highlight the edge of the intersections, and flashing yellow in-pavement guard lights located where taxiway C intersected runway 1R/19L (which ran perpendicularly to runways 28L and 28R and taxiway C). Figure 4 shows an illustration of the lighting on runway 28R and taxiway C. On the night of the incident flight, the runway and taxiway centerline lights were set at step 1 (out of 5).

Source: NTSB AIR, ¶1.4

The lowest adjusted radio altitude, which occurred when ACA759 passed over PAL115, was determined to be 60 ft, which was the height of the bottom of the landing gear above the ground. To confirm this altitude, the NTSB examined the image from the security camera video that showed ACA759 passing over PAL115 (figure 8). In that image, the vertical stabilizer of the PAL115 airplane (an A340) was well illuminated. The NTSB used known dimensions of an A340 vertical stabilizer to scale the image, measured the closest point between the two airplanes, and determined that measurement to be 13.5 ft. Because the security camera image of the airplanes was relatively small and pixilated, this measurement was estimated to be between 10 and 20 ft to account for the inherent uncertainty. In addition, this measurement assumed that ACA759 was directly above PAL115; the lateral separation could not be determined from the image of ACA759 passing over PAL115. The A340 airplane (including the vertical stabilizer) was reported to be 55 ft tall, so the altitude of the ACA759 fuselage as it passed over PAL115 would have been between 65 and 75 ft, which was consistent with the 60-ft adjusted radio altitude plus the 5-ft distance between the bottom of the landing gear and the bottom of the fuselage.

Source: NTSB AIR, ¶1.5.1

• Air Canada standard operating procedures stated that descent preparation should be completed before the top of the descent and listed the tasks that needed to be completed. The pilot monitoring (in this case, the first officer) was to use the MCDU to reference the radio/navigation page and set navigational aids into the FMC and then check that the ILS identifier shown on the PFDs was correct. The pilot flying (in this case, the captain) was to review the approach programming in the MCDU and complete an approach briefing, which included verifying that the primary approach aid (ILS) identifier and frequency were properly set.
• ATIS information Quebec indicated that the Quiet Bridge visual approach was in use and that arriving airplanes would be landing on runway 28R. The flight crew used Air Canada’s FMS Bridge visual approach procedure, which was based on the Quiet Bridge visual approach procedure, for the approach to runway 28R. Air Canada’s FMS Bridge visual approach chart consisted of two pages. The first page showed the approach procedure and included the ILS frequency for runway 28R in the plan view. The second page of the approach chart was in text format and indicated that Airbus A319/A320/A321 pilots should tune the ILS for runway 28R, which would provide flight crews with backup lateral guidance (via the localizer aligned with the runway heading) during the approach. This lateral guidance would supplement the visual approach procedures.
• The first officer stated that, when he set up the approach in the FMC, he missed the step in the procedure to manually tune the ILS frequency, and FDR data showed that no ILS frequency had been entered for the approach. According to Air Canada personnel, the FMS Bridge visual approach was the only approach in the company’s Airbus A320 database that required manual tuning of an ILS frequency, which might have contributed to the first officer’s failure to input the frequency (as discussed below). However, the first officer’s error should have been caught by the captain as part of his verification of the approach setup during the approach briefing. If cockpit voice recorder (CVR) information had been available for this incident (as discussed further in section 2.4), the NTSB might have been better able to determine whether distraction, workload, and/or other factors contributed to the first officer’s failure to manually tune the ILS frequency and the captain’s failure to verify that the ILS frequency was tuned. The NTSB concludes that the first officer did not comply with Air Canada’s procedures to tune the ILS frequency for the visual approach, and the captain did not comply with company procedures to verify the ILS frequency and identifier for the approach, so the crewmembers could not take advantage of the ILS’s lateral guidance capability to help ensure proper surface alignment.

Source: NTSB AIR, ¶2.2.2

• The NTSB concludes that the flight crew’s failure to manually tune the ILS frequency for the approach occurred because (1) the FMS Bridge visual approach was the only approach in Air Canada’s Airbus A320 database that required manual tuning of a navigation frequency, so the manual tuning of the ILS frequency was not a usual procedure for the crew, and (2) the instruction on the approach chart to manually tune the ILS frequency was not conspicuous during the crew’s review of the chart. Although the incident flight was operating under 14 CFR Part 129, the approach chart that the flight crew used was originally developed by an air carrier operating under 14 CFR Part 121. Therefore, the NTSB recommends that the FAA work with air carriers conducting operations under 14 CFR Part 121 to (1) assess all charted visual approaches with a required backup frequency to determine the FMS autotuning capability within an air carrier’s fleet, (2) identify those approaches that require an unusual or abnormal manual frequency input, and (3) either develop an autotune solution or ensure that the manual tune entry has sufficient salience on approach charts. The NTSB notes that, after the incident, Air Canada revised its procedures so that the FMS Bridge approach to runway 28R would be flown as an instrument approach.

Source: NTSB AIR, ¶2.2.2

• The flight crew had opportunities before the approach to learn about the runway 28L closure. The first opportunity occurred before the flight when the crewmembers received the flight release. Both crewmembers stated that they reviewed NOTAMs in the flight release. However, the first officer stated that he could not recall reviewing the specific NOTAM that addressed the runway 28L closure. Also, even though the captain stated that he saw the runway closure information, his actions in misaligning the airplane demonstrated that he did not recall that information when it was needed, and he thought that runway 28R was runway 28L. The second opportunity occurred in flight during the crewmembers’ preparations for the approach to runway 28R. Both crewmembers recalled reviewing ATIS information Quebec, which they received via an ACARS message in the cockpit, but neither crewmember recalled reviewing the specific NOTAM in the ATIS information that described the runway 28L closure.
• Because the flight crewmembers either did not review or could not recall the information about the runway 28L closure, they expected to see two parallel runways while on approach to SFO and further expected that they would need to fly the approach to the right-side surface. The flight crew’s recent experience flying into SFO would have reinforced these expectations. For example, when the first officer flew into SFO 2 nights before the incident, the airplane used for that flight landed on runway 28R at 2305, which was about 18 minutes before runway 28L was closed. Also, the captain stated that he had never seen runway 28L “dark” and that none of his previous landings at SFO occurred when a runway was closed.
• The NTSB concludes that, although the NOTAM about the runway 28L closure appeared in the flight release and the ACARS message that were provided to the flight crew, the presentation of the information did not effectively convey the importance of the runway closure information and promote flight crew review and retention.

Source: NTSB AIR, ¶2.3.1

The National Transportation Safety Board determines that the probable cause of this incident was the flight crew’s misidentification of taxiway C as the intended landing runway, which resulted from the crewmembers’ lack of awareness of the parallel runway closure due to their ineffective review of notice to airmen (NOTAM) information before the flight and during the approach briefing. Contributing to the incident were (1) the flight crew’s failure to tune the instrument landing system frequency for backup lateral guidance, expectation bias, fatigue due to circadian disruption and length of continued wakefulness, and breakdowns in crew resource management and (2) Air Canada’s ineffective presentation of approach procedure and NOTAM information.

Source: NTSB AIR, ¶3.2