Board Meeting - 9/25/2018
Update August 2, 2017:
On July 7, 2017, about 2356 Pacific daylight
time (PDT), Air Canada flight 759 (ACA759), an Airbus A320, C-FKCK, was cleared
to land on runway 28R at San Francisco International Airport (SFO), San
Francisco, California, but instead lined up on parallel taxiway C, where four
air carrier airplanes were awaiting takeoff clearance, including United
Airlines flight 1 (UAL1), a Boeing 787; Philippine Airlines flight 115, an
Airbus A340; United Airlines flight 863, another Boeing 787; and United
Airlines flight 1118, a Boeing 737 (see figure 1). ACA759 descended below
100 ft above the ground, and the flight crew advanced the thrust levers to
initiate a go-around about the time it overflew the first airplane on the
taxiway. The flight was operating under 14 Code
of Federal Regulations Part 129 as an international scheduled passenger
flight from Lester B. Pearson International Airport, Toronto, Canada. Night
visual meteorological conditions prevailed at the time of the incident.
Figure 1 shows the positions of the airplanes
on taxiway C. The top diagram is from Harris Symphony OpsVue radar track data
analysis, and the bottom picture is from the SFO airport video. Altitudes are
shown in mean sea level (msl); ground level is 13 ft msl. Airplanes in the top
diagram are not to scale.
The National Transportation Safety Board (NTSB)
was notified of the incident on Sunday, July 9, and initiated an investigation.
The NTSB investigator-in-charge has formed the following groups: Air Traffic
Control (ATC), Operational Factors, Human Performance, Airports, and Flight
Data Recorders (FDR). Parties to the
investigation include the Federal
Aviation Administration and the National Air Traffic Controllers Association. In
accordance with International Civil Aviation Organization Annex 13, the
Transportation Safety Board of Canada has appointed an accredited
representative for the State of Registration/Operator. The Canadian accredited
representative has appointed Air Canada, Transport Canada, and Air Canada
Pilots Association as technical advisors.
The ATC group reviewed
Airport Surface Detection Equipment Model X (ASDE-X)/Airport Surface
Surveillance Capability (ASSC) data associated with the incident.
The group, with members of the Operational Factors and Human Performance groups,
also conducted interviews with controllers and management personnel at the SFO
ATC tower and the Northern California Terminal Radar Approach Control (TRACON).
Operational Factors and Human Performance groups conducted interviews with the
incident flight crew and the flight crew of the airplane that landed on runway
28R minutes before the incident. The groups obtained statements from the flight
crewmembers of the aircraft that were holding on taxiway C at time of the incident.
Nighttime observations of the airport lighting from the ground and air were
also conducted. The
groups will be visiting Air Canada in Toronto,
where the flight crew was based, to review records and interview company
incident airplane’s cockpit voice recorder had been overwritten, so NTSB
investigators did not have that data.
update does not provide the probable cause for the incident and does not
contain analysis of information collected thus far in the NTSB’s ongoing
investigation. As such, no conclusions regarding the cause of the incident
should be made from this preliminary information.
The following facts are provided as
an investigative update:
28L was closed to accommodate construction; its approach and runway lights were
turned off, and a 20.5-ft-wide lighted flashing X (runway closure marker) was
placed at the threshold. Construction on runway 28L was part of a project that
started on February 21, 2017, and notices to airmen were issued to alert
operators of its operational status.
Terminal Information Service Q was current and included an advisory that runway
28L was closed and that its approach lighting system was out of service.
and approach lighting for runway 28R were on and set to default settings, which
included a 2,400-ft approach lighting system, a precision approach path
indicator, touchdown zone lights (white), runway centerline lights (white at
the approach end), runway threshold lights (green), and runway edge lights
(white at the approach end).
for taxiway C were also on and set to default settings that included centerline
lights (green) along its length. Default settings also included edge lights
(blue) and centerline lights (green) illuminating the transition or stub
taxiways from the runway to the taxiway.
The captain was the pilot
flying ACA759, and the first officer was the pilot monitoring. Both pilots held Canadian airline transport pilot
The captain had over 20,000 total
flight hours, of which about 4,797 hours were as captain in Airbus A320‑series
airplanes. The first officer had about 10,000 total flight hours, of which over
2,300 hours were in Airbus A320-series airplanes.=
were no known ATC equipment discrepancies.
air traffic staffing for the ATC tower midnight shift included two controllers.
On the evening of the incident, one controller was in the tower cab.
2349 PDT (7 minutes before the incident), all positions in the ATC tower (controller-in-charge
local control, local control assist, ground control, flight data, and clearance
delivery) were combined at the local control position.
2346:30 PDT, Northern California TRACON cleared ACA759 for the FMS bridge
visual runway 28R approach.
FDR data indicate that, during the final 3 nautical miles of
the approach, the airplane’s flightpath was lined up with the taxiway and
maintained the runway heading.
2355:46 PDT, when ACA759 was about 0.7 mile from the landing threshold and about
300 ft above ground level (agl), the flight crew contacted the ATC tower,
mentioned seeing lights on the runway, and requested confirmation that the
flight was cleared to land.
ACA759 approached SFO, at 2355:52 PDT, the airplane flew too far right of
course to be observed by the local controller’s ASDE-X/ASSC and was not visible
on the ASDE-X/ASSC display for about 12 seconds.
2355:56 PDT, when ACA759 was about 0.3 mile from the landing threshold, the
local controller confirmed and recleared ACA759 to land on runway 28R.
flight crew of the first airplane in queue on taxiway C (UAL1) transmitted
statements regarding ACA759, one of which mentioned the alignment of ACA759
with the taxiway while ACA759 was on short final (see figures 2 and 3). The flight
crew of the second airplane in queue on taxiway C switched on their airplane’s
landing lights as the incident airplane approached.
Figure 2 shows UAL1’s transmission at 2356:01
and ACA759’s position as it approaches the taxiway.
Figure 3 shows UAL1’s transmission at 2356:04
and ACA759’s position as it overflies the first airplane waiting on the
taxiway; note that the second airplane has turned on its landing lights.
incident pilots advanced the thrust levers when the airplane was about 85 ft
agl. FDR data indicate that the airplane was over the taxiway at this time, approaching
the vicinity of taxiway W.
2356:04 PDT, ACA759 reappeared on the local controller’s ASDE-X/ASSC display as
it passed over the first airplane positioned on taxiway C.
2.5 seconds after advancing the thrust levers, the minimum altitude recorded on
the FDR was 59 ft agl.
2356:10 PDT, the local controller directed ACA759 to go around. The airplane
had already begun to climb at this point (see figure 4).
Figure 4 shows the local controller’s
transmission to ACA759 at 2356:10 to go around and ACA759’s position after
overflying two airplanes on the taxiway.
postincident interviews, both incident pilots stated
that, during their first approach, they believed the lighted runway on their
left was 28L and that they were lined up for 28R. They also stated that they
did not recall seeing aircraft on taxiway C but that something did not look
right to them.
information will be released as warranted. The
docket for the investigation will be opened to the public before release of the
final report. NTSB investigations generally take 12 to 18 months to complete. Any updates can be found on this page.
The following is initial information on the incident investigation as of July 17, 2017:
Parties to the investigation are the Federal Aviation Administration and the National Air Traffic Controllers Association.
In accordance with International Civil Aviation Organization Annex 13, the Transportation Safety Board (TSB) of Canada has appointed an accredited representative for the State of Registration/Operator. The Canadian accredited representative has appointed Air Canada, Transport Canada, and Air Canada Pilots Association as technical advisors.
The NTSB investigator-in-charge has initially formed the following groups:
Air Traffic Control (ATC)
Flight Crew Operations (Ops)
Human Factors (HF)
Flight Data Recorder (FDR)
The Ops and HF groups interviewed the captain of the incident airplane on Friday and will be interviewing the first officer on Tuesday (July 18).
The ATC and HF groups began interviewing the ATC controllers at SFO and Northern California TRACON on Sunday and expect them to run through about Wednesday.
The TSB has provided the NTSB with the FDR data from the incident airplane.
The NTSB has obtained a security camera video from SFO of the incident approach that will be released along with the other factual information when the public docket for this incident is opened in the next several months.
Additional information will be released as warranted.