40 Mile Air Helio H-700 accident
Helio H-700 · Accident: on ground/water collision with terrain/water during landing
From Tok Junction Airport (TKJ) to an unrecorded destination
Event
- NTSB case
- ANC94LA107
- 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
- Charter & commuter
- 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
Helio H-700
- Aircraft type
- Helio H-700
- 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
- N4059H
- Operator
- 40 Mile Air
- Onboard fatalities
- Unknown
- Route
- From Tok Junction Airport (TKJ), AKTo 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 135: Air Taxi & Commuter
- 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
- Landing · landing roll
- 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
- On ground/water 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
- Substantial
Cause areas
- Landing gear, normal brake system › Failure, partial
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
AFTER LANDING ON THE GRAVEL BAR ON THE ROBERTSON RIVER, THE LEFT WHEEL'S BRAKE 'WENT SOFT.' THE PILOT ALLOWED THE AIRPLANE TO CONTINUE THE LANDING ROLL AND PRIOR TO STRIKING THE DITCH, HE INTENTIONALLY GROUND LOOPED THE AIRPLANE. DURING THE GROUND LOOP THE TAIL WHEEL STRUCK THE DITCH AND THE FUSELAGE BUCKLED. EXAMINATION OF THE AIRPLANE SHOWED THAT THE LEFT BRAKE'S TORQUE PLATE HAD SHEARED AND BROKEN THE BRAKE LINE.
Probable cause
THE PARTIAL FAILURE OF THE AIRPLANE'S NORMAL BRAKE SYSTEM.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC94LA107
- Event ID
- 20001206X01909
- Case number
- ANC94LA107
- 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 1994-08-13.
- API snapshot SHA-256: 93dbc3b9ee4d913b5f89925d917fa8cde3b92f52006b682de71526d3489e13ea; retrieved 2026-09-18T18:10:02.598Z.