Crest Airpark Airport
Aircraft Accident/Incident Report

Kent, Washington 98042
Monday, August 30, 1999 19:02 PDT

NTSB Narrative Summary Released at Completion of Accident

The co-owner/builder had been engaged in resetting the angle of attack (pitch angle) of the main rotor blades previous to the accident. Witnesses reported observing the gyrocopter depart to the south, proceed west, and then execute several oscillatory, rocking or pitching like maneuvers after which the aircraft entered a steep descent to the ground. Post-crash examination revealed that all eight of the main rotor blade pitch adjustment bolts were loose. Examination of the upper outboard shim plate of each blade attach bar revealed markings which clearly established a pitch bolt torque of 190 inch-pounds. Release of the main rotor blade pitch adjustment bolts would allow a rotor blade pitch change and subsequent loss of control.

NTSB Probable Cause Narrative

The owner/builder's failure to properly torque the rotor blade retaining bolts.

Event Information

Type of Event Accident
Event Date 8/30/1999
Event Day of the Week Monday
Time of Event 1902
Event Time Zone Pacific Daylight Time
Event City KENT
Event State WASHINGTON
Event Country --
Zipcode of the event site 98042
Event Date Year 1999
Event Date Month 8
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport CREST AIRPARK
Event Location Nearest Airport ID S36
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 --
Airport Elevation --
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1853 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 313
Weather Observation Facility ID RNT
Elevation of weather observation facility 29
Distance of event from weather observation facility (units?) 8
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 6500
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) 20
Dew Point at event time (in degress fahrenheit) 6
Wind Direction (degrees magnetic) 180
Variable Wind Indicator Unknown
Wind Speed (knots) 7
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
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 Fatal
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 1026
NTSB Notification Source --
NTSB Notification Date Aug 30 1999 12:00AM
NTSB Notification Time 1919
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Jan 23 2001 9:44AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N85Z
NTSB Number SEA99LA151
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Destroyed
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name ROTORDYNE
Aircraft Model 200
Aircraft Series Identifier 200
Aircraft Serial Number 1
Certified Max Gross Weight --
Aircraft Category Gyrocraft
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? Yes
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft --
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection May 15 1999 12:00AM
Airframe hours since last inspection --
Airframe Hours 56
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name HUBER, J. & MELLEMA, R.
Aircraft Owner Street Address 29648 179THE PLACE SE
Aircraft Owner City KENT
Aircraft Owner State WA
Aircraft Owner Country
Aircraft Owner Zipcode 98042
Operator is an individual? --
Operator Name MELLEMA, ROGER, D.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 17605 SE 288TH PLACE
Operator City KENT
Operator State WA
Operator Country
Operator Zip code 98042
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code S36
Departure City
Departure State
Departure Country
Departure Time 1900
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 Jan 23 2001 11:29AM
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 --