Aircraft Accident/Incident Report

Naches, Washington 98937
Saturday, May 9, 1998 16:55 PDT

NTSB Narrative Summary Released at Completion of Accident

The pilot reported that shortly after takeoff, he noticed that the rpm was low, as if it were bleeding off. The pilot tried to increase the rpm by using the increase/decrease button on the collective which had no effect. The pilot opted to reverse direction to return to land. The rpm continued to decrease and the pilot initiated an autorotation to a field in a narrow valley. The rpm continued to decay to a point in which the pilot could not perform a normal autorotation due to low airspeed and altitude. The helicopter landed hard and rocked forward onto it nose before settling back on the skids. The engine was removed and sent to a facility for a test run. During the engine run, there were no anomalies found that effected engine operation.

NTSB Probable Cause Narrative

Loss of engine power for undetermined reasons.

Event Information

Type of Event Accident
Event Date 5/9/1998
Event Day of the Week Saturday
Time of Event 1655
Event Time Zone Pacific Daylight Time
Event City NACHES
Event State WASHINGTON
Event Country --
Zipcode of the event site 98937
Event Date Year 1998
Event Date Month 5
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 1656 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 125
Weather Observation Facility ID YKM
Elevation of weather observation facility 1095
Distance of event from weather observation facility (units?) 12
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 10000
Lowest Non-Ceiling Height 7000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Overcast
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) 18
Dew Point at event time (in degress fahrenheit) 8
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Unknown
Wind Speed (knots) 3
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 29
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
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 3
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 603
NTSB Notification Source --
NTSB Notification Date May 9 1998 12:00AM
NTSB Notification Time 1855
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Feb 16 2001 11:58AM
User who most recently changed record dbo
Basic weather conditions Instrument Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N345SC
NTSB Number SEA98TA074
Missing Aircraft Indicator N
Federal Aviation Reg. Part Public Use
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Bell
Aircraft Model UH-1H
Aircraft Series Identifier UH-1H
Aircraft Serial Number 66-16345
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 13
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection AAIP
Date of Last Inspection Jun 14 1997 12:00AM
Airframe hours since last inspection 106
Airframe Hours 6821
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name PIERCE COUNTY SHERIFF'S DEPT
Aircraft Owner Street Address 930 TACOMA AVE.
Aircraft Owner City TACOMA
Aircraft Owner State WA
Aircraft Owner Country
Aircraft Owner Zipcode 98402
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 None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
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) Public Use
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1625
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 --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Oct 22 2001 3:26PM
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 --