Gnoss Airport
Aircraft Accident/Incident Report

Novato, California 94947
Wednesday, September 12, 1990 16:03 PDT

NTSB Narrative Summary Released at Completion of Accident

WHILE ON AN ADDED RATING FLIGHT TEST THE FAA DESIGNATED EXAMINER CALLED FOR A SIMULATED ENG FAILURE. THE PRIVATE PILOT APPLICANT IMMEDIATELY LOWERED THE COLLECTIVE AND BEGAN A 180 DEGREE TURN INTO THE WIND. WHEN THE HELICOPTER WAS ABOUT 160 DEGREES INTO THE TURN AND WAS ABOUT 50 FEET ABOVE THE GROUND THE PILOT BEGAN THE POWER RECOVERY BUT DUE TO THE HIGH SINK RATE THE SKIDS STRUCK THE SOFT DIRT OF A FRESHLY PLOWED FIELD CAUSING THE HELICOPTER TO ROLL TO THE RIGHT AND THE MAIN ROTOR BLADES TO STRIKE THE GROUND.

NTSB Probable Cause Narrative

THE PILOT'S IMPROPER EXECUTION OF THE AUTOROTATION. CONTRIBUTING TO THIS ACCIDENT WAS THE EXCESSIVE SINK RATE AND MISJUDGING OF THE ALTITUDE.

Event Information

Type of Event Accident
Event Date 9/12/1990
Event Day of the Week Wednesday
Time of Event 1603
Event Time Zone Pacific Daylight Time
Event City NOVATO
Event State CALIFORNIA
Event Country --
Zipcode of the event site 94947
Event Date Year 1990
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport GNOSS
Event Location Nearest Airport ID 056
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 0
Airport Elevation 1
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) 0
Air Temperature at event time (in degrees celsius) -18
Dew Point at event time (in degress fahrenheit) -18
Wind Direction (degrees magnetic) 270
Variable Wind Indicator Unknown
Wind Speed (knots) 15
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
Density Altitude (feet) 0
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) 2247
NTSB Notification Source --
NTSB Notification Date Sep 12 1990 12:00AM
NTSB Notification Time 1950
Fiche Number and/or location -used to find docket information 44596
Date of most recent change to record Dec 18 2002 11:28AM
User who most recently changed record NTSB\GIUV
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N2159W
NTSB Number LAX90LA321
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 Brantly Helicopter
Aircraft Model B-2B
Aircraft Series Identifier B-2B
Aircraft Serial Number 320
Certified Max Gross Weight 1670
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 2
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Unknown
Date of Last Inspection --
Airframe hours since last inspection 0
Airframe Hours --
ELT Installed Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name ROSENBERG, KENNETH P
Aircraft Owner Street Address 95 MANZANITA AVE
Aircraft Owner City NOVATO
Aircraft Owner State CA
Aircraft Owner Country
Aircraft Owner Zipcode 94945
Operator is an individual? --
Operator Name ROSENBERG, KENNETH P.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 95 MANZANITA AVE.
Operator City NOVATO
Operator State CA
Operator Country
Operator Zip code 94947
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) Instructional
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code
Departure City
Departure State
Departure Country
Departure Time 1603
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 Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
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 --