United Express Bombardier, Inc. CL-600-2C10 accident
Bombardier, Inc. CL-600-2C10 and Boeing 757-222 · Accident: ground collision during pushback
Event
- NTSB case
- SEA08LA061
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Aircraft 1 · Bombardier, Inc. CL-600-2C10
- Aircraft type
- Bombardier CL-600
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N705SK
- Operator
- United Express
- Onboard fatalities
- Unknown
- Route
- From San Francisco International Airport (KSFO), San Francisco, CATo Boise Air Terminal/Gowen Field (KBOI), Boise, ID
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Pushback/towing
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Ground collision
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Aircraft 2 · Boeing 757-222
- Aircraft type
- Boeing 757
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N508UA
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From San Francisco International Airport (KSFO), San Francisco, CATo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Pushback/towing
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Ground collision
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Personnel issues › Action/decision
- Personnel issues › Task performance
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
A Boeing 757-222 airplane and a Bombardier Inc. CL-600-2C10 were substantially damaged when the tails of both airplanes collided during the pushback process from two adjacent terminal gates during night visual meteorological conditions. The flight crew of the CL-600-2C10 reported that during the final stages of pushback from gate 79, they were in a stopped position with both engines running while their ground crew was in the process of disconnecting the tug when the collision occurred. Company maintenance personnel stated they were pushing the 757-222 back from gate 80 without the use of wing-walkers or tail walkers to relocate the airplane to another location on the airport and did not see the CL-600-2C10. Review of Air Traffic Control (ATC) communication recordings between ground control and both airplanes revealed that the 757-222 was initially cleared for pushback onto taxiway alpha from gate 80. About 41 seconds later, the ground controller cleared the CL-600-2C10 to push back onto taxiway alpha from gate 79. The recordings revealed that the ground controller did not advise either aircraft of near simultaneous adjacent pushback operations. The controller stated that he believed there was room for both aircraft to push back and did not foresee a traffic conflict.
Probable cause
The company tug operator of the other airplane's failure to maintain clearance with this aircraft during the pushback process. Also causal was the ground controller's failure to alert the pilot of this aircraft and tug operator of the other airplane of the simultaneous pushback occurring from adjacent gates. Contributing to the accident was the company's pushback operation without the use of wing/tail walkers.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA08LA061
- Event ID
- 20080118X00073
- Case number
- SEA08LA061
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: local date, investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 2008-01-14.
- API snapshot SHA-256: 6de388e3e0ed9ef421bd57a9e6f69e9e364151abe5bc2ad3ef6c08fea23c6b1c; retrieved 2026-09-13T18:13:07.131Z.
- The NTSB's operator name is blank for N705SK; the operator shown is the name the NTSB records it doing business as.