Aircraft Accident/Incident Report

Eagle, Alaska 99738
Friday, September 11, 1992 9:10 AKD

NTSB Narrative Summary Released at Completion of Accident

SHORTLY AFTER TAKEOFF THE PILOT RADIOED HE WAS RETURNING DUE TO POOR VISUAL FLIGHT CONDITIONS, AND WAS LAST SEEN CIRCLING THE EAGLE RUNWAY. THE WRECKAGE WAS FOUND APRX 7 HRS LATER 150 YDS NORTH OF THE RUNWAY. THE BLUE M/R BLADE WAS FOUND SEPARATED; THE TRAILING ATTACHMENT LUGS OF BOTH THE UPPER AND LOWER BLADE ROOT FITTINGS WERE FRACTURED THROUGH THE HOLES, AND THE LEAD LAG DAMPENER LUG WAS ALSO FRACTURED. METALLURGICAL EXAMINATION REVEALED FATIGUE PROGRESSION ON ALL FOUR ROOT FRACTURES. OPERATOR MAINTENANCE PERSONNEL STATED THAT THEY WERE NOT AWARE OF AD91-17-04 REQUIREMENT TO REMOVE & INSPECT THE M/R BLADES AT 100-HR INTERVALS.

NTSB Probable Cause Narrative

AN INFLIGHT FATIGUE FAILURE AND SEPARATION OF A MAIN ROTOR BLADE, INADEQUATE OPERATOR MAINTENANCE AND INSPECTION, AND MATERIAL DEFECT.

Event Information

Type of Event Accident
Event Date 9/11/1992
Event Day of the Week Friday
Time of Event 910
Event Time Zone --
Event City EAGLE
Event State ALASKA
Event Country --
Zipcode of the event site 99738
Event Date Year 1992
Event Date Month 9
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 0
Degrees magnetic from airport 0
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 Unknown
Sky Condition for Lowest Ceiling Unknown
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 1
Air Temperature at event time (in degrees celsius) 1
Dew Point at event time (in degress fahrenheit) -18
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) --
Intensity of Precipitation Light
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 3
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 610
NTSB Notification Source --
NTSB Notification Date Sep 11 1992 12:00AM
NTSB Notification Time 1836
Fiche Number and/or location -used to find docket information 46803
Date of most recent change to record Dec 11 2000 3:17PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1096X
NTSB Number ANC92FA164
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Company VFR
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name MCDONNELL DOUGLAS
Aircraft Model 369D
Aircraft Series Identifier 369D
Aircraft Serial Number 110836D
Certified Max Gross Weight 3000
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 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Aug 14 1992 12:00AM
Airframe hours since last inspection 57
Airframe Hours 3023
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name TUNDRA COPTERS INC.
Aircraft Owner Street Address 3868 UNIVERSITY AVE. SOUTH
Aircraft Owner City FAIRBANKS
Aircraft Owner State AK
Aircraft Owner Country
Aircraft Owner Zipcode 99709
Operator is an individual? --
Operator Name TUNDRA COPTERS INC.
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 3868 UNIVERSITY AVENUE, SOUTH
Operator City FAIRBANKS
Operator State AK
Operator Country
Operator Zip code 99709
Operator Code FXKA
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 Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
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
Departure Country
Departure Time 900
Departure Time Zone ADT
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 Approach
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:35AM
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 --