Accident - Oct. 7, 2003 - San Francisco, Calif.
The flight, operated by United Air Lines Inc., was scheduled to depart from San Francisco, Calif. en route to Osaka.
An All Nippon Airways (ANA) Boeing 777-281 and a United Airlines (UAL) Boeing 777-22B both sustained substantial damage during an on-ground collision between both airplanes' right wing tips. The collision occurred in a nonmovement area ramp surrounding the G terminal. This ramp area is under the control of a local ground control tower operated by United Airlines. Both aircraft were under the control of the ramp control tower at the time of the collision. The transfer of ground control responsibility from the ramp control tower to the Federal Aviation Administration Air Traffic Control Tower for an aircraft arriving or departing the G terminal is Spot 10. Spot 10 is where the G-ramp intersects taxiway A. Gate G-102 is the closest terminal gate to Spot 10 and is along the southern boundary of taxiway A. The ANA 777 had been cleared to taxi to Spot 10 by the ramp control tower was taxing outbound past gate G-102. The UAL 777 had been cleared by the ramp control tower to push back from gate G-102. Review of the recorded radio communications revealed that the ramp controller did not issue a cautionary advisory to either crew regarding the movements of the respective airplanes. The UAL 777 push back tractor driver saw the ANA 777 approach and stopped the push back just moments before the collision. The ANA flight crew saw the UAL 777 and maneuvered slightly to the left, away from the airplane, in an attempt to ensure wing tip clearance just prior to contact. None of the pilots on the ANA 777 could visually see their airplane's wingtips from the cockpit. The UAL 777's wing walker was on the left side of the airplane blocking traffic and noticed the ANA 777's approach and collision just moments after the UAL 777's push back was halted.
the failure of the taxiing Boeing 777's flight crew to maintain clearance from a Boeing 777 that was being pushed back from the gate. Contributing to the accident was the failure of the local ramp controller to caution either aircrew of a possible movement conflict.
1.1 HISTORY OF FLIGHT
On October 7, 2003, at 1157 Pacific daylight time, a Boeing 777-281, JA709A, operated as flight NH007 by All Nippon Airways (ANA), collided on the ground with a Boeing 777-22B, N222UA, operated by United Airlines (UAL) as flight UA809, at San Francisco International Airport, San Francisco, California. Both airplanes were substantially damaged. Flight UA809 was operating under the provisions of 14 CFR Part 121, and NH007 was operating under the provisions of 14 CFR Part 129. Flight NH007 was taxing for departure on a nonstop international flight to Narita International Airport, Tokyo, Japan, while UA809 was being pushed back for departure on a nonstop international flight to Kansai International Airport, Osaka, Japan. No injuries were sustained by either airplanes' crews or passengers. Visual meteorological conditions prevailed, and instrument flight rules (IFR) flight plans had been filed.
Flight NH007, while taxing outbound on taxiway A behind gate G-102, contacted the right outboard wing section of UA809 with its right wing tip. Flight UA809, at gate G-102, was undergoing a push back operation and was under the control of the tractor operator. Both airplanes were halted and towed to their respective passenger gates where the passengers deplaned.
A statement provided by the first officer of NH007 said that he saw a possible conflict and was maneuvering the airplane slightly to the left on the taxiway, away from UA809 to provide more clearance, when the wing tip contact occurred. None of the pilots on NH007 could visually see their airplane's wing tips from the cockpit.
The United Airlines ground crew consisted of a tug driver and a wing walker on the left side of UA809. Statements provided by the flight crew of UA809 reported that the United Airlines flight crew and push back tractor driver saw NH007 approach their position and they expressed some concern about possible clearance issues. The tractor driver halted the push back operation just before the collision.
The All Nippon Airways crew consisted of three pilots. The captain, who possessed an airline transport pilot certificate, a Boeing 777 type rating, and had accumulated 6,600 total hours of flight time, was in the left seat. The captain was not at the controls. The first officer, who possessed an airline transport pilot certificate, a Boeing 777 type rating, and had accumulated 6,127 total flight hours, was in the right seat. The first officer was the pilot at the controls. The third pilot was a relief pilot, designated as a captain, and possessed an airline transport pilot certificate, a Boeing 777 type rating, and had accumulated 8,759 hours of total flight time, was in the observers seat.
The United Airlines flight crew consisted of three pilots. The captain possessed an airline transport pilot certificate, a Boeing 777 type rating, and had accumulated 12,724 total hours of flight time, and was in the left seat. The first officer possessed an airline transport pilot certificate, a Boeing 777 type rating, and had accumulated 6,641 total flight time, and was in the right seat. A relief pilot was also present and seated on the flight deck.
The United Airlines push back crew consisted of the tug driver and a wing walker. A review of the push back crews' training records revealed that the tug driver was last signed off as qualified to dispatch and receive aircraft on June 8, 2003. The wing walker was signed off as qualified for wing walking duties on June 25, 2003.
The ramp tower controller had been working the "G" ramp for all of 2003 and had spent about half his time working that area during 2002. No records were located that documented ramp tower controller training or certification.
The ramp tower controls aircraft movement in the G-Terminal nonmovement area and is operated by United Airlines. Spot 10 is the location on taxiway A, adjacent to the G-ramp area, where the switch from the ramp tower control to SFO ground control is made.
Review of the ramp tower communication tape revealed that at 11:46:18, NH007 requested and was approved for the push back from gate G-95. At 11:53:56, ramp tower cleared NH007 to spot 10. At 11:54:06, UA809 requested its push back from G-102; ramp tower said that they would call UA809 back in 1 minute. At 11:54:36, ramp tower cleared UA809 for the push back. Notably, there was no comment or caution to either airplane concerning oncoming taxi traffic or a push back operation at G-102 by the ramp tower controller. At 11:56:28, UA809 called the ramp tower requesting fire trucks.
Review of the San Francisco Air Traffic Control Tower (SFOATCT) communications tape revealed that 1 minute 20 seconds prior to the wing tip collision (about 11:55:08), NH007 requested taxi clearance from SFO ground control.
1.11 FLIGHT RECORDERS
The flight data recorders were operating at the time of the accident. The airplane's Digital Flight Data Recorder (DFDR) and Digital Cockpit Voice Recorder (DCVR) were removed from the airplane and sent directly to the National Transportation Safety Board Vehicle Recorder laboratory for analysis. A Safety Board specialist plotted the last 19.3 minutes of the airplane's operation for engine performance, thrust, ground speed, heading, brake pressure, and weight on wheels switches. The plot showed that left wheel brake pressure was applied, and a corresponding heading change of about 5 degrees to the north occurred just prior to the collision. The flight data recorder and cockpit voice recorder factual reports are included in the official docket of this accident.
The airplane's Digital Flight Data Recorder (DFDR) and Digital Cockpit Voice Recorder (DCVR) were removed from the airplane and sent directly to the Safety Board Vehicle Recorder laboratory for analysis. No pertinent data was recovered by the DFDR or the DCVR because these units were not energized at the time of the collision. The flight data recorder and cockpit voice recorder factual reports are included in the official docket of this accident.
1.18 ADDITIONAL INFORMATION
1.18.1 San Francisco Airport Information
The nonmovement area surrounding the G terminal is under the control of a local control tower operated by United Airlines. The transfer of ground control from SFOATCT to the ramp tower for an aircraft arriving or departing the G terminal is Spot 10. Spot 10 is where the G-ramp intersects taxiway A and is a designated point where ground control authority is exchanged. Gate G-102 is the closest terminal gate to Spot 10 and is along the southern boundary of taxiway A.
1.18.2 UA809 Wing Walker/Guide Person
United Airlines push back procedures requires a "2 Person Pushback." This is accomplished using a wing walker or guide person in addition to the push back tractor driver. Additional wing walkers or guide persons may be added depending on the circumstances, such as, gate logistics, aircraft type, and weather. According to United Airlines procedural documents, the tractor driver is the person in charge of the dispatch and holds the ultimate responsibility for a safe dispatch.
One wing walker was assigned to UA809 and he was on station on the left side of the airplane. In his written statement, he said that while UA809 was being pushed back he was blocking traffic when he noticed UA809 stop. He then noticed NH007 approach on the other side, then heard a noise, and witnessed debris fall to the ground.
1.18.3 Boeing 777 Ground Maneuvering Characteristics
Depicted in Boeing's 777 Airplane Characteristics for Airport Planning document (D6-58329), 4.0 - Ground Maneuvering; when the airplane is in a ground turn the outboard wing tip of the Boeing 777 will continue to translate radially some distance beyond the original wing tip position depending on the angle imparted on the nose wheel.
1.18.4 Ramp Tower Responsibilities
A Memorandum of Understanding (MOU) between the Federal Aviation Administration "San Francisco Air Traffic Control Tower" (SFOATCT) and the San Francisco Terminal Equipment Co (SFOTEC), dated August 15, 2000, states that SFOTEC shall be the controlling agency for all boarding area "A" and "G" aircraft gates and direct departing aircraft to spots 1 or 10. San Francisco International Airport, Airport Operations Bulletins 00-04-AOB (July 31, 2000), 01-04-AOB (August 7, 2001), and 03-03-AOB (January 17, 2003) were issued in support of nonmovement ramp tower operations.
1.18.5 Surveillance Video
Examination of airport surveillance video recordings revealed the preimpact movement of the airplanes; however, the collision of the wing tips occurred outside the camera's field of view. A copy of the video is included in the official docket of this accident.