SEA97LA099 · Grumman G-164A
Grumman G-164A · Accident: in flight collision with terrain/water en route
From Rosalia Municipal Airport (72S) to an unrecorded destination
Event
- NTSB case
- SEA97LA099
- 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
- 1 · 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
Grumman G-164A
- Aircraft type
- Grumman G-164
- 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
- N7926
- Operator
- Joseph F. Dion · private individual
- Onboard fatalities
- Unknown
- Route
- From Rosalia Municipal Airport (72S), 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 137: Agricultural
- 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
- In flight collision with terrain/water
- 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
- Pilot in command › Clearance, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot-in-command departed the airport in a Grumman G-164A spray plane. En route to the destination field, and while overflying hilly terrain, the aircraft's tail wheel impacted the ground, followed by the main gear. The aircraft continued over an embankment, nosing over while crossing a paved road, before coming to rest and burning. There was no evidence that the pilot jettisoned the 2,040 pound herbicide load. Propeller slash marks early in the ground track indicated high engine RPM at the initial ground impact. Additionally, toxicological evaluation of samples from the pilot-in-command revealed 0.002 ug/ml of Tetrahydrocannabinol detected in blood, 0.08 ug/ml of Tetrahydrocannabinol Carboxylic Acid detected in blood, and 0.035 ug/ml of Tetrahydrocannabinol Carboxylic Acid detected in urine indicating fairly recent (within several hours) use of Marihuana.
Probable cause
The pilot-in-command's failure to maintain clearance with terrain. Factors contributing to the accident were, hilly terrain conditions and impairment due to recent use of marihuana.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA97LA099
- Event ID
- 20001208X08016
- Case number
- SEA97LA099
- 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. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1997-05-06.
- API snapshot SHA-256: b738a9a37cdf40d7652d34474c94ea806dacab282fa34692b76c606ec09ddfc2; retrieved 2026-09-20T22:58:24.847Z.