Bombardier INC CL 600 2B19 and Boeing 737 incident near San Francisco, California, December 15, 2016
On December 15, 2016 at about 1:43 am local time, 2 aircraft, Bombardier INC CL 600 2B19 (N986SW) and Boeing 737 (UNK), were involved in the same incident near San Francisco, California (San Francisco Intl airport). The NTSB record does not give the injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The captain’s inadvertent turn onto the incorrect taxiway and subsequent entry onto an active runway without a clearance, which resulted in the runway incursion.
The captain’s inadvertent turn onto the incorrect taxiway and subsequent entry onto an active runway without a clearance, which resulted in the runway incursion.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 15, 2016 · about 1:43 am local time
- Place
- San Francisco, California · San Francisco Intl · map
- Type
- Incident
- Injuries
- The NTSB record does not give the injuries.
- Weather
- visual conditions (good weather)
- Aircraft 1
- Bombardier INC CL 600 2B19 100, built 2004
- Registration
- N986SW · registry record · serial 7967
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
- Aircraft 2
- Boeing 737 924ER · all 737s on the register
- Registration
- UNK · no longer on the register · serial unk
- Damage
- Not recorded
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative for the Bombardier INC CL 600 2B19 final · quoted from the NTSB record
The runway incursion occurred when a CRJ inadvertently turned onto a highspeed exit taxiway and entered a runway after a Boeing 737 was cleared for takeoff on the same runway. Air traffic control ground controller issued the pilots of the CRJ taxi instructions to runway 28L from their ramp exit point. The instructions included clearance to cross runway 1 left and runway 1 right. Subsequently, the ground controller issued revised taxi instructions requiring the pilots to taxi on the taxiway closest to but parallel to runway 28L, then make a slight right turn to another taxiway to taxi to the approach end of runway 28L. During the taxi, the captain made a left turn onto a runway 28L highspeed exit and began to cross the runway hold short line, instead of making the slight right turn required to follow their taxi clearance. The captain reported that "something did not feel right" and stopped the airplane as the ground controller commanded the CRJ to stop. Although the captain of the CRJ had taxied at San Francisco International Airport (SFO) "many times" and was familiar with a hotspot in the area he made the mistaken turn, he had no explanation as to why he turned left at that point in the taxi. Recorded data indicated that the B737 passed in front of the CRJ within 188 feet laterally. The pilots of the B737 did not observe the CRJ during the takeoff roll. A review of air traffic control procedures and equipment showed that appropriate procedures were followed and there were no irregularities noted with the equipment. Federal Aviation Administration guidance on taxiway design indicated that complex intersections increase the possibility of pilot error. It offered the "three-node concept" which means that a pilot is presented with no more than three choices at an intersection. The intersection where the incursion began contained five choices: a left turn, a slight left turn, straight, slight right turn, and a right turn. After this incident, SFO placed temporary barricades at this intersection preventing its use before permanently closing the taxiway. Following this event, SkyWest Airlines developed and disseminated, on January 19, 2017, a "Flight Operations Message" to all pilots titled "Surface Movement Safety – Preventing Incursions" discussing the events surrounding this event and what crews should do to be vigilant. Although the area in which this incident occurred may have contributed to the captain’s mistaken turn, it was designated as a hot spot location that required enhanced crew vigilance during wayfinding through this area. Further, there were multiple cues at the intersection before the turn was made that could be used by the pilots to support the wayfinding task. Finally, the taxiway in which the captain mistakenly turned had signs, marking, and lighting to indicate both the identification of the taxiway and the identification of and presence of a runway and the fact it was active. These cues were not heeded by either pilot before the airplane entered the runway.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The NTSB's narrative for the Boeing 737 final · quoted from the NTSB record
The runway incursion occurred when a CRJ inadvertently turned onto a highspeed exit taxiway and entered a runway after a Boeing 737 was cleared for takeoff on the same runway. Air traffic control ground controller issued the pilots of the CRJ taxi instructions to runway 28L from their ramp exit point. The instructions included clearance to cross runway 1 left and runway 1 right. Subsequently, the ground controller issued revised taxi instructions requiring the pilots to taxi on the taxiway closest to but parallel to runway 28L, then make a slight right turn to another taxiway to taxi to the approach end of runway 28L. During the taxi, the captain made a left turn onto a runway 28L highspeed exit and began to cross the runway hold short line, instead of making the slight right turn required to follow their taxi clearance. The captain reported that "something did not feel right" and stopped the airplane as the ground controller commanded the CRJ to stop. Although the captain of the CRJ had taxied at San Francisco International Airport (SFO) "many times" and was familiar with a hotspot in the area he made the mistaken turn, he had no explanation as to why he turned left at that point in the taxi. Recorded data indicated that the B737 passed in front of the CRJ within 188 feet laterally. The pilots of the B737 did not observe the CRJ during the takeoff roll. A review of air traffic control procedures and equipment showed that appropriate procedures were followed and there were no irregularities noted with the equipment. Federal Aviation Administration guidance on taxiway design indicated that complex intersections increase the possibility of pilot error. It offered the "three-node concept" which means that a pilot is presented with no more than three choices at an intersection. The intersection where the incursion began contained five choices: a left turn, a slight left turn, straight, slight right turn, and a right turn. After this incident, SFO placed temporary barricades at this intersection preventing its use before permanently closing the taxiway. Following this event, SkyWest Airlines developed and disseminated, on January 19, 2017, a "Flight Operations Message" to all pilots titled "Surface Movement Safety – Preventing Incursions" discussing the events surrounding this event and what crews should do to be vigilant. Although the area in which this incident occurred may have contributed to the captain’s mistaken turn, it was designated as a hot spot location that required enhanced crew vigilance during wayfinding through this area. Further, there were multiple cues at the intersection before the turn was made that could be used by the pilots to support the wayfinding task. Finally, the taxiway in which the captain mistakenly turned had signs, marking, and lighting to indicate both the identification of the taxiway and the identification of and presence of a runway and the fact it was active. These cues were not heeded by either pilot before the airplane entered the runway.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record for the Bombardier INC CL 600 2B19 from the NTSB's investigation tables, in plain English
What happened, in order
- Runway incursion veh/AC/person during taxi (to runway) defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Expectation/assumption › Pilot
Pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 17,000 hours in all; 11,364 in this make and model; 136 in the last 90 days; 55 in the last 30 days
- Last flight review: August 24, 2016
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane
- Flight time: 1,552 hours in all; 71 in this make and model; 71 in the last 90 days
- Last flight review: September 10, 2016
- Medical certificate: Class 1 (with waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Maximum gross weight: 53,000 lb
- Seats: 53
- Landing gear: retractable
- Engine 1: Ge CF34 SERIES (turbofan); 0 hours total
- Engine 2: Ge CF34 SERIES (turbofan); 0 hours total
- Operator: Skywest Airlines INC
The flight
- Departed from: SFO San Francisco CA
- Destination: ONT Ontario CA
- Flight plan: IFR
- Runway 28L, 11,381 ft by 200 ft
- A second pilot was aboard
Weather at the time
- Light: night, dark
- Wind: from 170° at 9 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 2,700 ft; a few clouds at 2,100 ft
- Temperature: 57°F (14°C), dew point 54°F (12°C)
- Altimeter: 29.98 inHg
- Observation at 1:43 am from KSFO, 1 miles away
The factual record for the Boeing 737 from the NTSB's investigation tables, in plain English
What happened, in order
- Runway incursion veh/AC/person during takeoff defining event
The NTSB's findings
- cause Personnel issues › Action/decision › Info processing/decision › Expectation/assumption › Pilot of other aircraft
The aircraft
- Landing gear: retractable
- Operator: United Air Lines INC
The flight
- Departed from: SFO San Francisco CA
- Flight plan: IFR
- Runway 28L, 11,381 ft by 200 ft
- A second pilot was aboard
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.