Cottage Grove State Airport
Aircraft Accident/Incident Report

Cottage Grove, Oregon 97424
Saturday, July 20, 1996 16:30 PDT

NTSB Narrative Summary Released at Completion of Accident

During the takeoff roll on runway 33, the left main landing gear collapsed as the aircraft was accelerating through about 55 to 60 knots. The pilot/co-owner of the aircraft reported that he was unable to identify any mechanical malfunction which have would allowed the left main gear to collapse. He also reported that the gear down lights were illuminated during the takeoff checklist. The reason for the release of the left main gear from the down and locked position could not be determined. However, a 5 to 10 knot quartering right crosswind existed at the time of the takeoff. Once the aircraft settled onto the left wing, the pilot was unable to maintain directional control, and the aircraft slid into another aircraft that was parked off the runway.

NTSB Probable Cause Narrative

release of the main landing gear locking mechanism for undetermined reason(s).

Event Information

Type of Event Accident
Event Date 7/20/1996
Event Day of the Week Saturday
Time of Event 1630
Event Time Zone Pacific Daylight Time
Event City COTTAGE GROVE
Event State OREGON
Event Country --
Zipcode of the event site 97424
Event Date Year 1996
Event Date Month 7
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport COTTAGE GROVE STATE
Event Location Nearest Airport ID 61S
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles 0
Degrees magnetic from airport --
Airport Elevation 640
Weather Briefing Completeness Unknown
Investigator's weather source Pilot
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 Clear
Sky Condition for Lowest Ceiling None
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) 24
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 10
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) --
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1370
NTSB Notification Source --
NTSB Notification Date Jul 22 1996 12:00AM
NTSB Notification Time 1513
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 10:13AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N235WC
NTSB Number SEA96LA162
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Conkey/Wapelhorst
Aircraft Model LANCAIR 235
Aircraft Series Identifier LANCAIR 23
Aircraft Serial Number 001
Certified Max Gross Weight 1700
Aircraft Category Airplane
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 2
Number of Engines 1
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jul 18 1996 12:00AM
Airframe hours since last inspection 6
Airframe Hours 328
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name CONKEY & WAPELHORST
Aircraft Owner Street Address 4001 MONTEREY COURT
Aircraft Owner City NEWBURY PARK
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 91320
Operator is an individual? --
Operator Name CONKEY, DENIS, R.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 4001 MONTEREY COURT
Operator City NEWBURY PARK
Operator State CA
Operator Country
Operator Zip code 91320
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) Personal
Second Pilot on Board No
Departure Point Same as Event Yes
Departure Airport Code 61S
Departure City
Departure State
Departure Country
Departure Time 1630
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 Takeoff
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:34AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 33
Runway Length 3200
Runway Width 60
Sight Seeing flight No
Air Medical Flight No
Medical Flight --