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Air Evac EMS Bell 206L-1 accident

20 Apr 2004 · Boonville, IN, United States

Bell 206L-1 · Accident: in flight collision with terrain/water en route

From Huntingburg Airport (HNB) to Deaconess Hospital Heliport (16IN)

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Event

NTSB case
CHI04FA107
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
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
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

Bell 206L-1

Aircraft type
Bell 206
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
N137AE
Operator
Air Evac EMS
Onboard fatalities
Unknown
Route
From Huntingburg Airport (HNB), Huntingburg, INTo Deaconess Hospital Heliport (16IN), Evansville, IN
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
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
Substantial

Cause areas

  • Pilot in command › Altitude/clearance, not maintained
  • Pilot in command › Preflight planning/preparation, inadequate

Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.

NTSB narrative

The helicopter collided with up sloping terrain during a night air medical flight. The accident occurred while transporting a patient from one hospital to another. Examination of the accident site and wreckage revealed the helicopter impacted the terrain in a level flight attitude. The accident site was at an abandoned strip mine located in a rural area. The area contained very few ground structures to provide reference lighting. During post accident interviews the pilot stated that he remembered picking up the patient and the next thing he remembered is the helicopter tumbling. The flight nurse and paramedic on board did not recall there being any indication of a problem prior to impact. The destination hospital is located inside the Class C airspace of the Evansville Regional Airport (EVV). The air traffic control facility at EVV closes at 2300. Between 2328 and 2339, the pilot made 12 attempts to establish contact with approach control as he approached the Class C airspace. There was a time zone change at EVV 16 days prior to the accident. Examination of the cockpit revealed the altimeter was set at 30.08 inches of mercury. The current altimeter setting was 29.77 inches of mercury. This resulted in the altimeter indicating about 310 feet higher then the actual altitude of the helicopter. The pilot who flew the helicopter prior to the accident flight reported the radar altimeter was operating erratically. This pilot and the mechanic who maintained the helicopter, both stated the accident pilot was informed of the problem. Bench testing of the radar altimeter failed to duplicate the reported erratic operation. The decision height (DH) bug on the radar altimeter was found set to 60 feet. Company policy is that the DH bug be set to 500 feet during visual night operations. Examination of the airframe, engine, and flight controls failed to reveal any mechanical failure/malfunction.

Probable cause

The pilot's inadequate planning/decision which resulted in his failure to maintain terrain clearance. Contributing factors were the pilot's inadequate preflight planning, his diverted attention, and the dark night conditions.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record CHI04FA107
Event ID
20040426X00513
Case number
CHI04FA107
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 2004-04-21.
  • API snapshot SHA-256: 141fb0576899a30f5eeb46e96e08d3b58943d9de1d6e204380ecfa1486d341f3; retrieved 2026-09-18T13:00:56.418Z.