Aircraft Accident/Incident Report

Emida, Idaho 83861
Thursday, November 4, 1999 10:00 PST

NTSB Narrative Summary Released at Completion of Accident

Shortly after departure, during the initial climb, the helicopter experienced a sudden loss of power and the pilot initiated a forced landing to a nearby road. Post-accident inspection of the transmission assembly revealed that the splined engine adaptor was fractured due to a torsional overstress imposed on the transmission by the engine. It was determined that the adaptor fracture was secondary to another failure further along in the drive train or transmission. Further examination revealed that the helicopter's freewheeling sprag clutch assembly (located at the drive shaft input to the main transmission) exhibited signs of significant wear to include smearing, non-uniform surface wear and cam deformation. Damage or dragging in this assembly could account for the overstress fracture of the adaptor.

NTSB Probable Cause Narrative

Failure of the splined engine adaptor as a result of torsional overstress. Factors include a worn freewheeling clutch assembly.

Event Information

Type of Event Accident
Event Date 11/4/1999
Event Day of the Week Thursday
Time of Event 1000
Event Time Zone Pacific Standard Time
Event City EMIDA
Event State IDAHO
Event Country --
Zipcode of the event site 83861
Event Date Year 1999
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
Event Location Airport
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1053 Pacific Standard Time
Direction of event from weather observation facility (degrees) 25
Weather Observation Facility ID PUW
Elevation of weather observation facility 2555
Distance of event from weather observation facility (units?) 31
Time Zone of the weather observation PST
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 3000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 6
Dew Point at event time (in degress fahrenheit) -1
Wind Direction (degrees magnetic) 220
Variable Wind Indicator Unknown
Wind Speed (knots) 12
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 1
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1909
NTSB Notification Source --
NTSB Notification Date Nov 4 1999 12:00AM
NTSB Notification Time 1340
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Apr 26 2001 10:01AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N164KA
NTSB Number SEA00FA015
Missing Aircraft Indicator N
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 Kaman
Aircraft Model K-1200
Aircraft Series Identifier K-1200
Aircraft Serial Number 0014
Certified Max Gross Weight 12000
Aircraft Category Helicopter
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 1
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Oct 31 1999 12:00AM
Airframe hours since last inspection 13
Airframe Hours 5084
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name LONG-LINE LEASING, LLC.
Aircraft Owner Street Address 73 WEST 620 SOUTH
Aircraft Owner City OREM
Aircraft Owner State UT
Aircraft Owner Country
Aircraft Owner Zipcode 84058
Operator is an individual? --
Operator Name MOUNTAIN WEST HELICOPTERS, LLC
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 73 WEST 620 SOUTH
Operator City OREM
Operator State UT
Operator Country
Operator Zip code 84058
Operator Code
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation External Load
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Unknown
Indicates Domestic or International Flight Unknown
Operator carrying Pax/Cargo/Mail Unknown
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State ID
Departure Country
Departure Time 0
Departure Time Zone
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Takeoff
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Apr 26 2001 10:01AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --