Aircraft Accident/Incident Report

Baring, Washington 98224
Wednesday, June 14, 1989 11:50 PDT

NTSB Narrative Summary Released at Completion of Accident

WHILE LIFTING A LOG THE CREW HEARD UNUSUAL NOISES & FELT VIBRATIONS. THEY RELEASED THE LOG & FLEW TO A LANDING SITE TO CHECK THE AIRCRAFT. WHILE AT A HIGH HOVER THE AIRCRAFT BEGAN SPINNING AND THE PILOT EXECUTED A HOVERING AUTOROTATION. THE AIRCRAFT LANDED HARD AND ROLLED DOWN A HILL. INVESTIGATION REVEALED A FAILED TAIL ROTOR 42 DEG GEARBOX. THE BOARD'S METALLURGICAL EXAMINATION SHOWED THAT THE GEARBOX'S INPUT SPIRAL BEVEL GEAR HAD FAILED IN FATIGUE. THE ENG N2 TORQUE WAS RED-LINED AT 55 LBS. PILOT STATED THAT A DASH-5 TRANSMISSION WAS INSTALLED RATED FOR 60 LBS, BUT OBSERVED MARKED 55 LB LIMIT. NAVY OPERATORS MANUAL AND FAA TYPE CERTIFICATE BOTH LIST N2 TORQUE LIMIT AS 50 LBS.

NTSB Probable Cause Narrative

FATIGUE FAILURE OF THE TAIL ROTOR 42 DEGREE GEAR BOX DUE TO PILOT INDUCED OVERSTRESS. NAVY DATA AND FAA TYPE CERTIFICATE LIMITATIONS WERE NOT ADHERED TO.

Event Information

Type of Event Accident
Event Date 6/14/1989
Event Day of the Week Wednesday
Time of Event 1150
Event Time Zone Pacific Daylight Time
Event City BARING
Event State WASHINGTON
Event Country --
Zipcode of the event site 98224
Event Date Year 1989
Event Date Month 6
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 0
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1145 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 270
Weather Observation Facility ID PAE
Elevation of weather observation facility 603
Distance of event from weather observation facility (units?) 33
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 5500
Lowest Non-Ceiling Height 1200
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 20
Air Temperature at event time (in degrees celsius) 16
Dew Point at event time (in degress fahrenheit) 12
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Unknown
Wind Speed (knots) 10
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 3010
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 1
Injury Total None --
Injury Total Serious 1
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 1891
NTSB Notification Source --
NTSB Notification Date Jun 14 1989 12:00AM
NTSB Notification Time 1400
Fiche Number and/or location -used to find docket information 40979
Date of most recent change to record Dec 13 2000 12:47PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N157LC
NTSB Number SEA89FA111
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 133: Rotorcraft Ext. Load
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name OREGON HELICOPTERS
Aircraft Model UH-1L
Aircraft Series Identifier UH-1L
Aircraft Serial Number 157856
Certified Max Gross Weight 9500
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 9
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jun 11 1989 12:00AM
Airframe hours since last inspection 16
Airframe Hours 8299
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name TIMBERLINE AIR SERVICE, INC.
Aircraft Owner Street Address 24155 HEWETT ROAD
Aircraft Owner City ALPINE
Aircraft Owner State OR
Aircraft Owner Country
Aircraft Owner Zipcode 97456
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
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 No
Departure Airport Code
Departure City BARING
Departure State WA
Departure Country
Departure Time 900
Departure Time Zone PDT
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 Hover
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 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --