Incident Overview
On February 15, 2017, about 2000 Pacific Standard Time, a runway incursion occurred on runway 28L at San Francisco International Airport (SFO), San Francisco, California. The SFO Airport Traffic Control Tower (ATCT) local controller had cleared an Embraer ERJ170, registration N214NN, operating as Compass Airlines flight 6081 (CPZ6081), to land on runway 28L. Subsequently, the same controller instructed an Airbus A320, registration N627VA, operating as Virgin America flight 920 (VRD920), to line up and wait (LUAW) on the same runway. The closest proximity occurred when CPZ6081 executed a tower-directed go-around and overflew VRD920 while that aircraft was in the LUAW position. Radar data indicated CPZ6081 had descended to about 125 feet mean sea level at the time of the overflight. Both flights were operating under 14 Code of Federal Regulations Part 121. CPZ6081 was a regularly scheduled flight from Los Angeles International Airport (LAX) to SFO, and VRD920 was a regularly scheduled flight from SFO to McCarran International Airport (LAS) in Las Vegas, Nevada. No injuries were reported to crew or passengers of either flight, and no damage occurred to either aircraft. Night visual meteorological conditions prevailed at the time of the incident.
History of Flight
About 1944, the pilot of CPZ6081 checked in with the Northern California Terminal Radar Approach Control (NCT) Boulder sector approach controller, who advised that automatic terminal information service (ATIS) information was "tango" and to expect a runway 28L visual approach to SFO. The pilot acknowledged. By 1953, the controller instructed the pilot to contact the Woodside approach controller, which the pilot did, reporting level at 8,000 feet. The Woodside controller issued a heading toward the airport and later a descent to 4,000 feet. About 1955, the Woodside controller cleared CPZ6081 for a visual approach to runway 28R, but the pilot read back "cleared visual approach runway 28 right." About 1957, the Woodside controller instructed the pilot to contact SFO tower. The pilot contacted SFO tower, reporting "visual runway 28 left." The local controller responded with wind information and the pilot acknowledged "cleared to land." According to the CPZ6081 pilot, the flight was a standard flight with an easy day; they briefed for a visual approach to 28L and backed it up with an ILS approach. The flight was switched to tower frequency prior to the outer marker and was cleared to land about 10 miles from the threshold. The captain requested a wind check from the ATCT controller.
About 1959, the local controller instructed VRD920 to LUAW on runway 28L; the pilot acknowledged and taxied onto the runway. The captain of VRD920 stated that after receiving the LUAW clearance, he illuminated the nose light, runway turnoff lights, and strobes, but kept landing lights off per company guidance until takeoff clearance. The flight crew reported no maintenance deferrals and that exterior lights were operable. The captain did not hear CPZ6081's check-in or landing clearance. After about a minute and a half wait on the runway, the VRD920 pilots monitored their Traffic Collision Avoidance System (TCAS) and discussed the close proximity of the target on final, noting difficulty determining which runway the target was aligned with due to proximity of runways 28L and 28R.
At 2000:13, the Airport Surface Surveillance Capability (ASSC) system in the SFO ATCT generated an aural and visual alert indicating a conflict. Radar and ASSC data showed CPZ6081 about 0.85 mile from the runway 28L threshold at 500 feet, with VRD920 on the runway. Six seconds later, the local controller instructed CPZ6081 to go around; the pilot acknowledged. ASSC data indicated CPZ6081 was about 0.56 mile from the threshold at 300 feet at the time of the go-around instruction. The flight crew complied. The local controller then issued climb-out instructions. As CPZ6081 executed the go-around, radar data showed it descended to about 125 feet as it overflew runway 28L. The VRD920 flight crew heard the go-around clearance and felt vibration from the overflight. The local controller then instructed CPZ6081 to contact NCT approach, and one minute later issued takeoff clearance to VRD920. CPZ6081's first officer described the approach end of the runway as "darker than normal," and the captain reported seeing what appeared to be a "vague light" on the runway. The remainder of both flights was uneventful.
Radar and Weather Data
ASSC data from SFO was used as the source for this report. The weather at SFO at the time of the incident, as reported by the automated surface observing system (ASOS) at 1956 PST, was: wind from 200° at 19 knots, visibility 10 statute miles or greater; few clouds at 10,000 feet agl, broken ceiling at 12,000 feet agl, broken skies at 18,000 feet agl; temperature 16°C, dew point 4°C; altimeter 29.99 inHg.