Individually Owned: 150,657
Corporate Owned: 137,281
N/A Airport
Aircraft Accident/Incident Report
Beluga, Alaska 99695
Saturday, December 15, 2012 10:05 AKS
NTSB Narrative Summary Released at Completion of Accident
The commercial helicopter pilot was transporting a 1,000-pound external sling load attached to a lightweight, synthetic 100-foot long-line when the load began to spin and swing underneath the helicopter. As the helicopter neared its destination, it suddenly yawed, and then started to spin uncontrollably, and the pilot immediately jettisoned the external load. As the helicopter continued to spin uncontrollably, it descended into an area of tall trees and then came to rest on its left side.
A postaccident inspection of the helicopter revealed that portions of the severed lightweight synthetic long-line had become entangled in the tail rotor gearbox output shaft and that the tail rotor gearbox assembly was torn free of the tail boom. Examination of the long-line revealed that its entire length was tightly wrapped, knotted, and kinked. The pilot reported that he had not received training in procedures to adequately stabilize external sling loads. Given the postaccident condition of the lightweight synthetic long-line, the pilot's statements, and the lack of a rotating swivel, it is likely that, once the external load began to spin, the long-line continued to tangle and tightly knot and ultimately reached its breaking point. Once the synthetic long-line separated, the portion still attached to the belly of the helicopter recoiled upward and eventually became entangled with the tail rotor gearbox output shaft. In addition, it is likely the pilot did not adequately monitor the condition of the external sling load while en route, and he failed to recognize the need to stabilize the load.
NTSB Probable Cause Narrative
The pilot's failure to stabilize the external load, which led to the synthetic long-line separating about midspan and the remaining line becoming entangled in the tail rotor gearbox output shaft and resulted in the separation of the tail rotor gearbox and subsequent loss of control. Contributing to the accident was the pilot's inadequate training.
Event Information
| Type of Event | Accident |
| Event Date | 12/15/2012 |
| Event Day of the Week | Saturday |
| Time of Event | 1005 |
| Event Time Zone | -- |
| Event City | Beluga |
| Event State | ALASKA |
| Event Country | -- |
| Zipcode of the event site | 99695 |
| Event Date Year | 2012 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 610827N |
| Event Location Longitude | 1510624W |
| Event Location Airport | N/A |
| Event Location Nearest Airport ID | -- |
| Indicates whether the acc/inc occurred off or on an airport | Off Airport/Airstrip |
| Distance from airport in statute miles | -- |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 953 AKS |
| Direction of event from weather observation facility (degrees) | 83 |
| Weather Observation Facility ID | PANC |
| Elevation of weather observation facility | 100 |
| Distance of event from weather observation facility (units?) | 40 |
| Time Zone of the weather observation | AKS |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 7000 |
| Sky/Lowest/Cloud Conditions | Few |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 10 |
| Air Temperature at event time (in degrees celsius) | -14 |
| Dew Point at event time (in degress fahrenheit) | -16 |
| Wind Direction (degrees magnetic) | 340 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.15 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 32563 |
| NTSB Notification Source | FAA Anchorage, ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Apr 25 2014 4:32PM |
| User who most recently changed record | stam |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | C-GYPH |
| NTSB Number | ANC13FA017 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 133: Rotorcraft Ext. Load |
| Type of Flight Plan filed | Company VFR |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | EUROCOPTER |
| Aircraft Model | AS350 B3 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 3688 |
| Certified Max Gross Weight | 6173 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Aug 13 2012 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 5559 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | C126 |
| Aircraft Owner Name | Prism Helicopters LTD |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Pitt Meadows |
| Aircraft Owner State | BC |
| Aircraft Owner Country | CA |
| Aircraft Owner Zipcode | V3Y 2B3 |
| Operator is an individual? | No |
| Operator Name | PRISM HELICOPTERS INC |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Wasilla |
| Operator State | AK |
| Operator Country | USA |
| Operator Zip code | 99654 |
| Operator Code | EOOA |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | -- |
| Certified for Part 133 or 137 Operation | -- |
| Operator Certificate Number | EOOA634D |
| Indicates whether an air carrier operation was scheduled or not | -- |
| Indicates Domestic or International Flight | -- |
| Operator carrying Pax/Cargo/Mail | -- |
| Type of Flying (Per_Bus / Primary) | External Load |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | PABG |
| Departure City | Beluga |
| Departure State | AK |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | PABG |
| Destination City | Beluga |
| Destination State | AK |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Apr 25 2014 4:32PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |