Nevada County Airport
Aircraft Accident/Incident Report

Grass Valley, California 95945
Friday, October 11, 1991 16:00 PDT

NTSB Narrative Summary Released at Completion of Accident

IN AN ORAL STATEMENT, THE PILOT SAID THAT AS HE APPROACHED THE AIRPORT HE OBSERVED SQUALL LINE ACTIVITY AND DECIDED TO ORBIT UNTIL THE WEATHER CLEARED. AFTER THE WEATHER CONDITIONS VISUALLY IMPROVED, THE PILOT ENTERED THE PATTERN FOR LANDING. HE STATED THAT ON SHORT FINAL APPROACH THE AIRCRAFT ENCOUNTERED SEVERE TURBULENCE AND A DOWN DRAFT. THE PILOT INITIATED A GO AROUND, HOWEVER, THE AIRCRAFT ROLLED VIOLENTLY AND THE WING TIP STRUCK THE GROUND. AN AIRPORT ATTENDANT STATED THAT HE WAS IN THE OFFICE WHERE THE WEATHER OBSERVATION INSTRUMENTS ARE LOCATED AT THE TIME OF THE ACCIDENT. HE SAID THAT THE WINDS WERE 30 TO 40 KNOTS WITH SUDDEN 180 DEGREE CHANGES IN DIRECTION AT THE TIME THE PILOT ATTEMPTED HIS APPROACH. THUNDERSTORM CLOUDS WERE VISIBLE IN THE DISTANCE AND THE AIRPORT WAS EXPERIENCING INTERMITTENT HEAVY RAIN SHOWERS.

NTSB Probable Cause Narrative

THE INADVERTENT ENCOUNTER WITH A MICROBURST/DOWNBURST PHENOMENA ASSOCIATED WITH THUNDERSTORM ACTIVITY. A FACTOR IN THE ACCIDENT WAS THE FAILURE OF THE PILOT TO ADEQUATELY ASSESS THE WEATHER CONDITIONS DURING THE LANDING ATTEMPT.

Event Information

Type of Event Accident
Event Date 10/11/1991
Event Day of the Week Friday
Time of Event 1600
Event Time Zone Pacific Daylight Time
Event City GRASS VALLEY
Event State CALIFORNIA
Event Country --
Zipcode of the event site 95945
Event Date Year 1991
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport NEVADA COUNTY
Event Location Nearest Airport ID 017
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 3150
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 4000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 50
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Variable
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 40
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 3
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 1668
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 45545
Date of most recent change to record Dec 12 2000 10:48AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N9559R
NTSB Number LAX92LA012
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 BEECH
Aircraft Model K35
Aircraft Series Identifier K35
Aircraft Serial Number D6125
Certified Max Gross Weight 2949
Aircraft Category Airplane
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 4
Number of Engines 1
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Nov 3 1990 12:00AM
Airframe hours since last inspection 57
Airframe Hours 2380
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name MIKE COLLISHAW
Aircraft Owner Street Address 1515 WALSH AVENUE
Aircraft Owner City SANTA CLARA
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 95050
Operator is an individual? --
Operator Name MIKE COLLISHAW
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address 1515 WALSH AVENUE
Operator City SANTA CLARA
Operator State CA
Operator Country
Operator Zip code 95050
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 No
Departure Airport Code RHV
Departure City SAN JOSE
Departure State CA
Departure Country
Departure Time 1500
Departure Time Zone PDT
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Approach
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 7
Runway Length 3920
Runway Width 50
Sight Seeing flight No
Air Medical Flight No
Medical Flight --