DEN87DTG02 · Bell 47G-4A
Bell 47G-4A · Accident: vortex turbulence encountered while maneuvering
Event
- NTSB case
- DEN87DTG02
- 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
Bell 47G-4A
- Aircraft type
- Bell 47
- 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
- N2238W
- Operator
- James H Morten · private individual
- Onboard fatalities
- Unknown
- Route
- From not recordedTo 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
- Maneuvering · aerial application
- 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
- Vortex turbulence encountered
- 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 › In-flight planning/decision, improper
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
THE PLT RPRTD THAT WHEN HE TOOK OFF FM A NRBY NURSE TRUCK, THE WIND WAS FM THE NE AT 5 TO 7 MPH. HE MADE AN OBSERVATION PASS ACROSS THE AREA TO BE TREATED, THEN BGN A DSCNDG RGT TURN TO MAKE A SWATH RUN IN THE OPPOSITE DRCTN. HE STATED HE WAS UNAWARE OF A WIND-SHIFT TO THE NW. SUBSEQUENTLY, THE HELICOPTER ENCOUNTERED WHAT THE PLT THOUGHT WAS WAKE TURBC FM THE OBSERVATION PASS. THE ACFT BGN TO SETTLE & THE PLT INCREASED THE COLLECTIVE IN AN EFFORT TO STOP THE DSCNT. THE PLT SAID THE 'RECOVERY ENDED IN A DEEP CANYON APPROX 150 TO 200 FT DEEP. EMERGENCY TRIP DOOR SOLENOID TO RELEASE LOAD FAILEDTO WORK. WAS ONLY ABLE TO SUSTAIN HOVER FOR APPROX 2 MIN BEFORE A/C SETTLED ON A 30 TO 40 (DEGREE) EMBANKMENT & SLID DOWN 40 FT TO TREES, TAIL FIRST.' RPRTDLY THE DUMP VLV FAILED TO OPERATE DUE TO CORROSION FM CHEMICALS CARRIED ON THE PREVIOUS FLT.
Verbatim NTSB analysis from the NTSB dataset
Sources
NTSB record DEN87DTG02
- Event ID
- 20001213X32052
- Case number
- DEN87DTG02
- 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: dcfcfee83c9e5922a5d3692b07ad687ec21cf4f8430702001910963f88273298; retrieved 2026-09-23T12:08:16.242Z.