SEA05MA202 · Agusta A109A II
CJ Systems Aviation Group Agusta A109A II · Accident: loss of control in flight while maneuvering
From Harborview Medical Center Heliport (WA53) to Arlington Municipal Airport (AWO)
Event
- NTSB case
- SEA05MA202
- 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
- 3 · 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
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Instrument Meteorological Cond
Agusta A109A II
- Aircraft type
- Agusta A109
- 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
- N655GS
- Operator
- CJ Systems Aviation Group
- Onboard fatalities
- Unknown
- Route
- From Harborview Medical Center Heliport (WA53), Seattle, WATo Arlington Municipal Airport (AWO), Arlington, WA
- 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
- Maneuvering
- 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
- Loss of control in flight
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Destroyed
Cause areas
- Reason for occurrence undetermined
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
After dropping off a patient, the pilot and two flight nurses boarded the air ambulance helicopter for a dark night cross country flight from a hospital back to their base. A company VFR flight plan was filed. Radar data shows the helicopter departed the hospital, proceeded northbound over ocean water, following the coastline at an altitude of approximately 800 feet msl. Just prior to the loss of radar contact, the helicopter entered a left turn towards the west, away from the shoreline. No eye witnesses to the accident were located. A number of ear witnesses heard a low flying helicopter and then the sound of impact. The witnesses reported low clouds and restricted visibility in rain, mist and fog in the vicinity of the accident site. The closest aviation weather reporting station, located 5 miles northwest of the accident site, reported winds from the southwest at 6 knots, with visibilities restricted in light rain and mist, with a ceiling ranging from 200 to 800 feet. Conditions rapidly deteriorated within 30 minutes of the accident, with visibilities lowering to 1/4 miles in dense fog with ceilings at 200 feet. Plotting the helicopter's flight track on weather radar images indicates the helicopter encountered an area of light precipitation as it approached the accident site. The pilot was instrument rated and met the currency requirements for IFR flight, and the helicopter was equipped and certified for IFR flight. The pilot had been employed as an air ambulance helicopter pilot in the accident area for the past 16 years. He had 7,990 hours helicopter flight time with 4,192 hours in the accident make and model, 2,396 hours night flight time and 672 hours instrument flight time. Examination of the helicopter's maintenance records revealed no evidence of any uncorrected maintenance discrepancies. Damage observed on the recovered wreckage was consistent with the helicopter impacting the water in an uncontrolled descent. Examination of the recovered wreckage revealed no evidence suggesting mechanical malfunction or failure. However, the majority of the helicopter, including most of the flight control system and all flight instruments and avionics, was not recovered, precluding determination of the reasons for the loss of control.
Probable cause
Loss of control for an undetermined reason during maneuvering flight, which resulted in an in-flight collision with water.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA05MA202
- Event ID
- 20051007X01599
- Case number
- SEA05MA202
- 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: 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 2005-09-30.
- API snapshot SHA-256: d5afcaf96e4d484191b49011a303d1d1ea8a1726c09fbdf8a22be0e2aa8d4464; retrieved 2026-09-20T17:51:57.452Z.