SEA93FA010 · Piper PA-12
Piper PA-12 · Accident: in flight collision with object while maneuvering
From Graham US Forest Service Airport (U45) to Boise Air Terminal/Gowen Field (BOI)
Event
- NTSB case
- SEA93FA010
- 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
- 2 · 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
Piper PA-12
- Aircraft type
- Piper PA-12
- 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
- N3743M
- Operator
- Harpham, Samuel E. · private individual
- Onboard fatalities
- Unknown
- Route
- From Graham US Forest Service Airport (U45), GRAHAM AIRSTRIP, IDTo Boise Air Terminal/Gowen Field (BOI), 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 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
- In flight collision with object
- Also codedOther events the NTSB coded in the sequence, such as a wire strike after a loss of power. Flight Findings uses them for its kinds of event. Glossary
- Tree(s)
- 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 OF THE PIPER PA-12 SPENT ABOUT 45 MINUTES MANEUVERING AT LOW LEVEL IN AND AROUND STEEP CANYONS IN THE ROUGH MOUNTAINOUS TERRAIN. HE THEN LANDED AT THE REMOTE FOREST SERVICE AIRSTRIP, AND SPENT ABOUT AN HOUR ON THE GROUND. AFTER DEPARTURE FROM THE AIRSTRIP, THE AIRCRAFT WAS OBSERVED FLYING LESS THAN 50 FEET ABOVE TREETOP LEVEL ALONG AN UNEVEN FORESTED RIDGE. WITNESSES INDICATED THAT, ALTHOUGH THEY LOST SIGHT OF THE AIRCRAFT BEHIND SOME TREES ABOUT FIVE SECONDS PRIOR TO THE ACCIDENT, THE ENGINE SOUNDED AS IF IT WAS RUNNING SMOOTHLY, AND AT OR NEAR FULL POWER, UNTIL THEY HEARD THE NOISE FROM THE IMPACT.
Probable cause
THE PILOT'S FAILURE TO MAINTAIN ADEQUATE TERRAIN CLEARANCE. FACTORS INCLUDE MOUNTAINOUS/HILLY TERRAIN, TREES, AND THE PILOT'S DIVERTED ATTENTION.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record SEA93FA010
- Event ID
- 20001211X15958
- Case number
- SEA93FA010
- 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: f7d3d731ee50c2aa2f86f5ceac42ccce35b6d8b340083c5a4aac6e4af764df5b; retrieved 2026-09-21T00:50:36.681Z.