# NTSB ANC04LA079: Hughes 500D, Iliamna, AK, July 14, 2004

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 14, 2004, 11:00 local (19:00 UTC)
- Place: Iliamna, AK
- Coordinates: 59.883335, -155.300003
- Nearby events: https://openairdocs.org/map.md?lat=59.8833&lon=-155.3000&mi=10
- Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 28, 2004
- Report: Approved by Office Director
- NTSB office: Alaska Regional Office
- Parties: Anchorage FSDO-03
- NTSB case key (mKey): 59650
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC04LA079
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59650/pdf
- Page: https://openairdocs.org/ntsb/ANC04LA079

## Probable cause

The ground crew's failure to use proper procedures while securing a sling load to the helicopter, which resulted in foreign object damage to the helicopter's main rotor system while idling.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Miscellaneous/other, standing - idling rotors
  - rotorcraft operations - improper, ground personnel (cause)
  - rotor system,main rotor - foreign object damage (cause)

## Analysis

The commercial helicopter pilot reported the helicopter was sitting and running at flight-idle while he and two helpers prepared a sling load.  He said he was climbing into the helicopter, and did not see the activity, but one of the helpers standing near the cargo door threw a rope to the other helper.  He said the rope was inadvertently tossed into the main rotor system, and wrapped around the rotor head.  The pilot indicated that the main rotor blades and rotor head received structural damage during the encounter with the rope.

## Factual narrative

On July 14, 2004, about 1100 Alaska daylight time, a Canadian registered Hughes 500D helicopter, C-GVHG, sustained substantial damage when a ground crew member inadvertently threw a rope into the idling main rotor system at a remote mine site, about 20 miles west of Iliamna, Alaska.  The helicopter was being operated by Prism Helicopter LTD, of Wasilla, Alaska, as a visual flight rules (VFR) external load flight under Title 14, CFR Part 133, when the accident occurred.  The solo commercial pilot was not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 15, the pilot said the helicopter was sitting and running at flight-idle while he and two helpers prepared a sling load.  He said he was climbing into the helicopter, and did not see the activity, but one of the helpers standing near the cargo door threw a rope to the other helper.  He said the rope was inadvertently tossed into the main rotor system, and wrapped around the rotor head.  The pilot said that the main rotor blades and rotor head received structural damage during the encounter with the rope.  He noted that there were no known mechanical anomalies with the helicopter prior to the accident.

During a telephone conversation with the IIC on July 15, the director of operations for the operator said ground crew members receive specific training for handling ropes and equipment around operating helicopters.

## Aircraft

- Registration: C-GVHG (not matched to a registry record)
- Reported make and model: Hughes 500D
- Category: Helicopter
- Serial number: 310916D
- Engines: Allison 250-C20B 375 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 133
- Operator: Prism Helicopters Ltd
- Registered owner: Prism Helicopters
- Airworthiness certificate: Standard, Normal
- Departed: PAIL, Iliamna, AK
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; injuries: none; commercial; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,595 total, 1,137 in this make and model, 1,450 as pilot in command, 408 in the last 90 days, 141 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Lowest ceiling: 4,000 ft overcast
- Temperature: 64 °F

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.

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