SEA00FA021 · Bell 206L-3
Bell 206L-3 and Kiro Bell 206B · Accident: midair collision en route
Event
- NTSB case
- SEA00FA021
- 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
- 0
- 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
- General aviation
- 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 · Bell 206L-3
- Aircraft type
- Bell 206
- Category
- Helicopter
- 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
- N206AC
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From King County International Airport - Boeing Field (BFI), Seattle, WATo Vancouver International Airport (YVR), Vancouver
- 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 91: General Aviation
- 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
- En route · cruise
- First occurrenceThe 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
- Midair 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 · Bell 206B
- Aircraft type
- Bell 206
- Category
- Helicopter
- 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
- N5735A
- Operator
- Kiro
- Onboard fatalities
- Unknown
- Route
- From King County International Airport - Boeing Field (BFI), Seattle, WATo 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 91: General Aviation
- 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
- En route · cruise
- First occurrenceThe 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
- Midair 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
- Pilot in command › Visual lookout, inaccurate
- Pilot in command › Visual lookout, inadequate
- Pilot of other aircraft › Visual lookout, inadequate
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot of N5735A reported that he was transitioning the area of Lake Union (on a local electronic news gathering flight) in a south-southwesterly direction when the two aircraft collided. He stated that he simultaneously saw the other aircraft and felt the impact. After the collision, the pilot initiated a descent and landed on a nearby helipad. The pilot reported that prior to the collision he was monitoring the common traffic advisory frequency (CTAF) for Lake Union (122.90). He stated that just before transitioning the area he reported his position, altitude and heading on 122.90. The pilot of N206AC reported that he departed Boeing Field and was proceeding northbound. He stated that he had just cleared Boeing's Delta airspace and switched to Seattle Radio (122.50) when he '...experienced a loud bang and vibration in the main rotor system'. The pilot initiated a descent to a nearby helipad, and was able to land without further incident. The pilot stated he did not see the other aircraft before, or after the collision. There were no reported mechanical failures or malfunctions that may of contributed to the accident. A calculated convergence angle between the two aircraft indicated that there were no visual restrictions that would have prevented the pilot from seeing the other aircraft.
Probable cause
Adequate separation and lookout not maintained by the pilots of both aircraft.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA00FA021
- Event ID
- 20001212X20173
- Case number
- SEA00FA021
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- 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: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 646133bb329fe4a4c9b18a35732d349d78a884625a1cf640ce2e83d42581de10; retrieved 2026-09-21T20:20:56.725Z.