# NTSB CEN19LA092: Bell 407, N450AM, Union Center, SD, March 3, 2019

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: March 3, 2019, 00:13 local (07:13 UTC)
- Place: Union Center, SD
- Coordinates: 44.564723, -102.661392 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.5647&lon=-102.6614&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Defining event: [Standing-engine(s) shutdown: Ground collision](https://openairdocs.org/ntsb-events/200)
- Highest injury: Minor injuries
- Injuries: 1 minor, 2 uninjured
- Status: Completed, report August 10, 2020
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: Federal Aviation Administration
- NTSB case key (mKey): 99047
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19LA092
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99047/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99047
- Page: https://openairdocs.org/ntsb/CEN19LA092

## Probable cause

The ambulance driver’s failure to see the helicopter’s rotating main rotor blades in dark night conditions, which resulted in the ambulance’s inadvertent collision with the helicopter. Contributing to the accident was the ambulance driver's failure to follow procedures when approaching the helicopter.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Sensory ability/limitation: visual function](https://openairdocs.org/ntsb-findings/02011510): Personnel issues › Physical · Ground crew (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 1 case](https://openairdocs.org/ntsb-findings/02011510/cases.md?model=1182154), [All aircraft, 32 cases](https://openairdocs.org/ntsb-findings/02011510/cases.md)
- [Light condition: dark](https://openairdocs.org/ntsb-findings/03036020): Environmental issues › Conditions/weather/phenomena · Effect on personnel (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 2 cases](https://openairdocs.org/ntsb-findings/03036020/cases.md?model=1182154), [All aircraft, 448 cases](https://openairdocs.org/ntsb-findings/03036020/cases.md)
- [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Ground crew (probable cause); cases with it: [Bell Helicopter Textron Canada 407, 2 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md?model=1182154), [All aircraft, 397 cases](https://openairdocs.org/ntsb-findings/02041010/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Standing-engine(s) shutdown: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event); cases with it: [Bell Helicopter Textron Canada 407, 1 case](https://openairdocs.org/ntsb-events/200/sequence.md?model=1182154), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md)

## Analysis

The helicopter pilot, flight nurse, and flight paramedic had arrived at a landing zone to pick up a patient at night. After landing, the pilot rolled the engine throttle to idle and briefed the flight crew that they were clear to depart the helicopter. About 20 seconds later, the ground ambulance drove toward the helicopter, and the main rotor blades impacted the top of the ambulance. The flight paramedic was thrown to the ground and sustained minor injuries. The main rotor blades, tailboom, and fuselage sustained substantial damage. The ground ambulance driver stated that he saw the crew open the doors and get out of the helicopter, so he moved the ambulance ahead to get closer to the helicopter. The driver stated that he did not realize "that the helicopter blades were still rotating." The operator confirmed that the ambulance driver had received training, which indicated that ground personnel are not to approach the helicopter until the blades had stopped rotation. In addition, the general operations manual stated that ground personnel will not come beneath the rotor disk until directed to do so by the pilot.

## Factual narrative

On March 3, 2019, about 0013 mountain standard time, a Bell 407 helicopter, N450AM, was substantially damaged after landing near Union Center, South Dakota. The pilot and flight nurse were not injured. The flight paramedic sustained minor injuries. The helicopter sustained substantial damage. The helicopter was owned by Air Methods and operated under the provisions of Title 14 Code of Federal Regulations Part 135. Dark night visual meteorological conditions prevailed, and a company visual flight rules flight plan was filed and activated for the flight. The on-demand air medical flight departed Spearfish, South Dakota, about 2337, and was en route to Union Center to pick up a patient.The helicopter had arrived at the landing zone at Union Center to pick up a patient. After landing, the pilot rolled the engine throttle to idle and briefed the flight crew that they were clear to depart the helicopter. About 20 seconds into the "cool down" process the ground ambulance drove towards the helicopter and subsequently the main rotor blades impacted the top of the ambulance. The flight paramedic was thrown to the ground during the collision. The main rotor blades, tail boom, and fuselage sustained substantial damage. The ground ambulance driver saw the crew open the doors and get out of the helicopter, so he moved the ambulance forward to get closer to the helicopter. The ground ambulance driver stated that he did not realize "that the helicopter blades were still rotating." Air Methods confirmed that the ambulance driver had received their training. A review of that training indicated that ground personnel are not to approach the aircraft until the blades had stopped rotation. The training also indicated that ground vehicle lights should be turned off while the helicopter is landing. An excerpt from the Air Methods General Operations Manual stated that ground personnel will not come beneath the rotor disk until directed to do so by the pilot in command; the pilot will use appropriate hand signals to do so.

## Aircraft

- Registration: [N450AM](https://openairdocs.org/aircraft/N450AM), registered now, S/N 54435, built 2013 (OpenAirDocs)
- Reported make and model: Bell 407
- Registry model: [Bell Helicopter Textron Canada 407](https://openairdocs.org/model/bell-helicopter-textron-canada-407) (registry code 1182154) (OpenAirDocs)
- Registry engine: [Rolls-Royce 250-C47B](https://openairdocs.org/engine/rolls-royce-250-c47b) (registry code 54585, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 54435
- Year built: 2013
- Airframe hours: 2105
- Engines: Rolls Royce 250-C47B 650 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 135
- Operator: Air Methods Corp, doing business as Black Hills Life Flight
- Registered owner: Air Methods Corp
- Airworthiness certificate: Standard, Normal
- Last inspection: Continuous airworthiness, March 1, 2019
- Departed: KSPF, Spearfish, SD
- Destination: Union Center, SD
- Flight plan: Company VFR
- Equipment: ADS-B, Satellite tracking device, Auto-pilot, Electronic multifunction display, Electronic primary flight display

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; injuries: none; commercial, private; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review November 27, 2018; seat: right; restraint: 4-point; flight hours: 2,138 total, 130 in this make and model, 2,138 as pilot in command, 18 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 330° at 13 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: -11 °F, dew point -20 °F
- Altimeter: 30.42 inHg
- Observed at: KRAP

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20190303000829A](https://openairdocs.org/incident/20190303000829A), Mar 3, 2019: Bell Helicopter Textron Canada 407, Union Center, SD, Substantial damage. On March 03, 2019, at 00:13HRS. Local time, a Bell 407 helicopter, registered to and operated by air methods corp. was involved in an accident after landing…

## Docket (4 files)

The files NTSB released with the investigation on January 15, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99047. 4.9 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479911&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF
- Pilot, Flight Crew, Driver Statements (item 2, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479912&FileExtension=.PDF&FileName=Pilot,%20Flight%20Crew,%20Driver%20Statements-Master.PDF
- Accident Report Photographs (item 3, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479913&FileExtension=.PDF&FileName=Accident%20Report%20Photographs-Master.PDF
- General Operations Manual, Training Excerpts (item 4, .PDF, 329 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40479914&FileExtension=.PDF&FileName=General%20Operations%20Manual,%20Training%20Excerpts-Master.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.