Scappoose Industrial Airpark Airport
Aircraft Accident/Incident Report

Scappoose, Oregon 97056
Monday, September 17, 2007 17:45 PDT

NTSB Narrative Summary Released at Completion of Accident

The pilot was a potential buyer of the airplane and was flying it on short final approach. He said that he attempted to correct for a sink rate, which included pulling back full aft on the control stick to arrest the descent. The airplane's nose then abruptly pitched down about 45 degrees and the airplane struck the runway. A visual examination of the airplane's flight control system by Federal Aviation Administration (FAA) inspectors revealed that the flight control stick gimbal mechanism had fractured and the control stick was separated from the mechanism. The flight control stick gimbal mechanism and a portion of the fuselage structure were shipped to the Safety Board's Materials Laboratory for a metallurgical examination. According to the metallurgical examination, the fatigue cracking of the fuselage tube structure in the area of the control stick gimbal mechanism emanated from the root of a weld in an area between tube joints. The Safety Board's senior metallurgist reported that the fatigue had propagated through approximately 30 percent of the wall thickness. The fatigue crack was located near an area of the fuselage tube that contained a 0.7-inch-long region of incomplete weld penetration at the root of the weld.

NTSB Probable Cause Narrative

A loss of aircraft pitch control due to the fatigue failure of the fuselage tube structure at the flight control stick gimbal mechanism due to an incomplete weld penetration at the root of the weld.

Event Information

Type of Event Accident
Event Date 9/17/2007
Event Day of the Week Monday
Time of Event 1745
Event Time Zone Pacific Daylight Time
Event City Scappoose
Event State OREGON
Event Country --
Zipcode of the event site 97056
Event Date Year 2007
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 454626N
Event Location Longitude 1225100W
Event Location Airport Scappoose Industrial Airpark
Event Location Nearest Airport ID SPB
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 58
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1753 Pacific Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID SPB
Elevation of weather observation facility 58
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation PDT
Lighting Conditions Day
Lowest Ceiling Height 6000
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 18
Dew Point at event time (in degress fahrenheit) 4
Wind Direction (degrees magnetic) 290
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 7
Wind Velocity Indicator --
Wind Gust Indicator --
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.12
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
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) 24749
NTSB Notification Source FAA
NTSB Notification Date Sep 17 2007 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Dec 9 2008 4:38PM
User who most recently changed record coos
Basic weather conditions Visual Meteorological Cond
FAA District Office WP-PDX-FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1415B
NTSB Number LAX07LA280
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Root
Aircraft Model Sherpa
Aircraft Series Identifier --
Aircraft Serial Number 0012
Certified Max Gross Weight --
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? Yes
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 --
Date of Last Inspection --
Airframe hours since last inspection --
Airframe Hours --
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name Byron L. Root
Aircraft Owner Street Address --
Aircraft Owner City Clackamas
Aircraft Owner State OR
Aircraft Owner Country USA
Aircraft Owner Zipcode 97015
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City Clackamas
Operator State OR
Operator Country USA
Operator Zip code 97015
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation --
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) Personal
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code SPB
Departure City Scappoose
Departure State OR
Departure Country USA
Departure Time --
Departure Time Zone PDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code SPB
Destination City Scappoose
Destination State OR
Destination Country USA
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Dec 9 2008 4:39PM
User who most recently changed record coos
Since inspection or accident --
Event Location Runway Number and Location 33
Runway Length 5100
Runway Width 100
Sight Seeing flight No
Air Medical Flight No
Medical Flight --