Aircraft Accident/Incident Report

Marblemount, Washington 98267
Monday, February 13, 1995 10:20 PST

NTSB Narrative Summary Released at Completion of Accident

THE MAIN ROTOR DRIVESHAFT FAILED DUE TO FATIGUE FAILURE WHILE THE PILOT WAS CONDUCTING HELICOPTER LOGGING OPERATIONS. THE MAIN ROTOR DRIVESHAFT HAD 952 HOURS SINCE NEW, AND HAD BEEN INSTALLED NEW AT THE MOST RECENT GEARBOX OVERHAUL. OVERHAUL PERIOD AND MAIN ROTOR DRIVESHAFT RETIREMENT TIME ARE 2500 HOURS. THE PILOT WAS NOT AT AN ALTITUDE OR AIRSPEED WHERE A SUCCESSFUL AUTOROTATION COULD BE ACCOMPLISHED.

NTSB Probable Cause Narrative

FATIGUE FAILURE OF THE MAIN ROTOR DRIVESHAFT.

Event Information

Type of Event Accident
Event Date 2/13/1995
Event Day of the Week Monday
Time of Event 1020
Event Time Zone Pacific Standard Time
Event City MARBLEMOUNT
Event State WASHINGTON
Event Country --
Zipcode of the event site 98267
Event Date Year 1995
Event Date Month 2
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 Witness
Time of the weather observation 0
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID
Elevation of weather observation facility 0
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 75
Air Temperature at event time (in degrees celsius) -2
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 45
Variable Wind Indicator Unknown
Wind Speed (knots) 5
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 8
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
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) 112
NTSB Notification Source --
NTSB Notification Date Feb 13 1995 12:00AM
NTSB Notification Time 1110
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 7 2000 4:03PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1099T
NTSB Number SEA95LA051
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 133: Rotorcraft Ext. Load
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name SIKORSKY
Aircraft Model S-58JT
Aircraft Series Identifier S-58JT
Aircraft Serial Number 58-1646
Certified Max Gross Weight 12500
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 2
Number of Engines 2
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Feb 9 1995 12:00AM
Airframe hours since last inspection 14
Airframe Hours 9776
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name GLACIER HELICOPTERS
Aircraft Owner Street Address 3937 WILLIAMSON WAY
Aircraft Owner City BELLINGHAM
Aircraft Owner State WA
Aircraft Owner Country
Aircraft Owner Zipcode 98225
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code GKIL
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) Other Work Use
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1010
Departure Time Zone PST
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 Maneuvering
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
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 --