Air Canada Flight 759

Air Canada
Industry	Airline
Founded	April 10, 1937; 89 years ago
Key people	Not specified
Products	Air transportation services
Website	www.aircanada.com

On July 7, 2017, an Airbus A320-211 operating as Air Canada Flight 759 nearly triggered a catastrophic event at San Francisco International Airport. Originating from Toronto Pearson International Airport, the flight was authorized to land on runway 28R but inadvertently lined up with the adjacent taxiway, where four fully loaded and fueled passenger jets were queued for departure. The flight crew initiated a go-around maneuver and subsequently landed safely on runway 28R. The aircraft on the taxiway took off without incident.

The National Transportation Safety Board (NTSB) investigation revealed that the aircraft descended to just above ground level before climbing again, missing a collision by only a few feet. The primary cause was determined to be confusion among the crew between the runway and the parallel taxiway, exacerbated by failure to utilize the instrument landing system (ILS) and pilot fatigue. Aviation experts emphasized that this event narrowly avoided becoming one of the most devastating aviation accidents in history, considering the number of passengers and aircraft involved.

Incident

At 11:46 p.m. local time, Air Canada Flight 759, carrying 135 passengers and five crew members, received clearance to land on Runway 28R. The neighboring Runway 28L had been closed since 10 p.m., with its lights off except for a flashing "X" at its eastern end. The captain was flying while the first officer monitored instruments. Both pilots mistakenly identified Runway 28R as 28L and aligned their approach toward Taxiway C, despite differences in lighting color and brightness. Initial inquiries found that runway and taxiway lighting were set to default configurations, and air traffic control broadcasts confirmed that 28L was closed and unlit. Given clear weather conditions, the pilots relied on a visual approach instead of using the instrument landing system.

Taxiway C was occupied by four aircraft—three from United Airlines and one from Philippine Airlines—waiting for takeoff clearance. At 11:55:46 p.m., noticing aircraft lights approximately , AC759’s pilot requested permission to land on runway 28R; the controller responded at 11:55:56 p.m., stating, "There's no one on 28R but you," when AC759 was still from the runway threshold. The pilots did not recall seeing any planes on Taxiway C but sensed something unusual. To alert AC759, the Philippine Airlines crew switched on their landing lights. At 11:56:01 p.m., United Airlines flight UA001’s pilot interrupted communications, exclaiming, "Where is this guy going? He's on the taxiway." The controller instructed AC759 to abort its landing at 11:56:10 p.m.; by then, AC759 had already begun climbing but had not yet acknowledged the command.

Following this, UA001’s pilot reported that Air Canada had flown directly overhead; air traffic control confirmed this observation. During its initial approach, AC759 passed roughly above Taxiway C, descending to as low as , coming within laterally of the four aircraft before initiating a go-around. Flight data indicated that thrust levers were advanced at altitude; however, the plane descended further to about just seconds later. An uninvolved pilot remarked that a delay of five seconds in initiating pull-up could have resulted in a collision with United Airlines flight UAL 863. The vertical separation between AC759’s underside and the tail of the Philippine Airlines Airbus A340 measured less than .

San Francisco International Airport was pioneering in deploying an Airport Surface Surveillance Capability (ASSC) system designed to alert controllers about potential runway-taxiway conflicts. Nonetheless, AC759 vanished from ASSC radar for twelve seconds—from shortly after requesting landing clearance until UA001’s pilot spotted AC759 on Taxiway C—because it deviated from the intended path toward Runway 28R.

After executing a go-around successfully, AC759 made a second approach and landed without issue. At that time, a single air traffic controller managed both ground and tower frequencies—a task usually divided between two controllers.

Aircraft

The aircraft operating Air Canada Flight 759 that evening was registered as C-FKCK, an Airbus A320-200 with an age of roughly 25 years, having received its certification on January 17, 1992.

Details of aircraft and flights involved in the event
Carrier	Flight Number	Aircraft Type	Seating Capacity	Registration	Departure	Arrival
Air Canada	ACA 759	Airbus A320-200	146	C-FKCK	Toronto	San Francisco
United Airlines	UAL 001	Boeing 787-9	252	N29961	San Francisco	Singapore
Philippine Airlines	PAL 115	Airbus A340-300	254	RP-C3441	San Francisco	Manila
United Airlines	UAL 863	Boeing 787-9	252	N13954	San Francisco	Sydney
United Airlines	UAL 1118	Boeing 737-900ER	179	N62895	San Francisco	Cancún

Investigation

Although the incident did not meet the criteria for mandatory reporting under federal regulations at that time, former NTSB chairman Jim Hall described it as "the most significant near-miss of the decade," calling for a reassessment of reporting protocols. The National Transportation Safety Board (NTSB) spearheaded the inquiry, supported by the Federal Aviation Administration (FAA), while Canada's Transportation Safety Board (TSB) acted as a liaison between Air Canada and the NTSB.

The configuration of runways at San Francisco International Airport requires exact precision during flight operations, with runways 28R and 28L separated by only 750 feet and Taxiway C positioned less than 500 feet from runway 28R. Certain airlines mandate the use of the instrument landing system (ILS) regardless of visibility conditions, which could have alerted the crew of AC759 to their incorrect alignment. California Insurance Commissioner Dave Jones, who was a passenger aboard AC759, officially requested Air Canada's full cooperation throughout the investigation.

Initial findings from the NTSB indicated that AC759 descended to approximately 59 feet above ground level—just marginally higher than the 55-foot tail height of Boeing 787-9 aircraft occupying Taxiway C. Unfortunately, the cockpit voice recorder data had been overwritten before investigators were notified, as the plane completed three additional flights on July 8 prior to authorities being informed on July 9.

Final stages

During a board session on September 25, 2018, the NTSB identified the probable cause as pilot confusion between Taxiway C and runway 28R, attributed to failure to note runway 28L's closure in the NOTAM briefing. Additional factors included non-utilization of the ILS within the flight management system (FMS) during visual approach and pilot fatigue. The crew’s circadian rhythms corresponded to a Toronto local time of approximately 3:00 AM; notably, the first officer had not rested adequately for over twelve hours, while the captain exceeded nineteen hours without significant rest—both surpassing U.S. fatigue regulations for pilots.

Transport Canada announced plans to harmonize its pilot rest requirements with international standards by late 2018. Although new rules introduced in December 2018 moved closer to global benchmarks, they were criticized by the Air Canada Pilots Association as insufficient.

The FAA received six recommendations stemming from this event: identifying approaches necessitating unusual manual frequency inputs and marking them clearly on aeronautical charts; enhancing NOTAM review processes to highlight critical information; mandating alerts for aircraft misalignment within Class B or C airspace; improving airport infrastructure to warn of collision risks and distinctly mark closed runways—since lighting used during construction on runway 28L resembled ramp illumination.

In response, Air Canada is revising its approach charts specific to San Francisco International Airport, incorporating dedicated simulator training tailored to SFO conditions, addressing cognitive biases related to expectations during approaches, and equipping newer fleet models such as the Airbus A220 and Boeing 737 MAX with dual head-up displays to boost situational awareness under low visibility and complex approach scenarios.

The NTSB’s conclusive report issued in September 2018 included five formal recommendations. Due to delays in pilot incident reporting, cockpit voice recordings were overwritten after subsequent flights. The board advocates for expedited incident notification procedures and is considering proposals to extend cockpit voice recorder retention periods from two hours up to twenty-five hours.

A former NTSB investigator criticized the agency’s reactive stance and highlighted shortcomings in investigative procedures. While faulting Air Canada for tardy reporting and loss of voice recordings, the report acknowledged that notification requirements apply only when an aircraft lands or takes off from a taxiway or narrowly avoids collision following a runway incursion—conditions not met in this case. The report also dismissed a similar taxiway event involving Alaska Airlines at Seattle-Tacoma in December 2015 as preliminary at that time.

Following recommendations for NOTAM enhancements, an ICAO initiative was launched aiming to overhaul the system. NTSB Chairman Robert L. Sumwalt characterized existing NOTAMs as "a collection of irrelevant information largely ignored by users."

Aftermath

In response to the event, the Federal Aviation Administration implemented changes in early August to nighttime landing protocols at SFO. These adjustments prohibited visual approaches during nighttime hours "when a neighboring parallel runway is closed" and required the use of instrument approaches, either through ILS or satellite-based guidance. Additionally, the FAA mandated the presence of two air traffic controllers in the control tower "until the conclusion of the late-night arrival peak."

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