Aircraft Accident/Incident Report

Chico, California 95926
Saturday, September 22, 2001 20:05 PDT

NTSB Narrative Summary Released at Completion of Accident

During a steep approach to a confined landing zone, the helicopter encountered a brown out condition due to dust and dirt clouds formed by the rotor downwash, and the helicopter collided with trees during an attempted go-around. After circling the landing area twice the pilot approached the landing zone from the west to the east. Ground witnesses and the onboard flight nurses said the approach was completely normal until the helicopter neared the ground. About 30 feet above the ground there was a dirt/dust condition created from the helicopter's rotor blades and the witnesses lost sight of the helicopter. One flight nurse, who was using night vision goggles to assist the pilot with ensuring that the landing zone was clear, told investigators that as the dust cloud formed their outside vision was completely obscured. The flight nurse asked the pilot if he could see anything, but the pilot did not respond. The medical crew estimated that the pilot started to go around about 15 feet above the ground, and during the go-around the helicopter drifted about 90 feet to the south and impacted trees. Witnesses recalled hearing the engine power up and then heard the helicopter impact trees. During the engine power up and go-around, no problems were heard with the engine. The on board medical crew said that they did not perceive any mechanical difficulties with the helicopter.

NTSB Probable Cause Narrative

the pilot's inadequate in-flight decision and delay in initiating a go-around during an encounter with brown out conditions, which led to his failure to maintain alignment of the helicopter with the intended go-around flight path and a resulting collision with trees.

Event Information

Type of Event Accident
Event Date 9/22/2001
Event Day of the Week Saturday
Time of Event 2005
Event Time Zone Pacific Daylight Time
Event City Chico
Event State CALIFORNIA
Event Country --
Zipcode of the event site 95926
Event Date Year 2001
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 394405N
Event Location Longitude 1215101W
Event Location Airport --
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 1953 Pacific Daylight Time
Direction of event from weather observation facility (degrees) 350
Weather Observation Facility ID OVE
Elevation of weather observation facility 192
Distance of event from weather observation facility (units?) 4
Time Zone of the weather observation PDT
Lighting Conditions Night
Lowest Ceiling Height --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 27
Dew Point at event time (in degress fahrenheit) 12
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator Calm
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.83
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 1
Injury Total Minor --
Injury Total None 1
Injury Total Serious 1
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 17735
NTSB Notification Source FAA
NTSB Notification Date Sep 22 2001 12:00AM
NTSB Notification Time 2130
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jun 8 2005 12:51PM
User who most recently changed record NTSB\JOHB
Basic weather conditions Visual Meteorological Cond
FAA District Office FAA-WP-SAC

Aircraft Involved

Aircraft #1

Aircraft Registration Number N911NT
NTSB Number LAX01LA304
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed Company VFR
Flight plan Was Activated? Yes
Damage Destroyed
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Aerospatiale
Aircraft Model AS350BA
Aircraft Series Identifier --
Aircraft Serial Number 1556
Certified Max Gross Weight 4630
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 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Sep 5 2001 12:00AM
Airframe hours since last inspection 44.6
Airframe Hours 7786.9
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name N T ENLOE MEMORIAL HOSPITAL
Aircraft Owner Street Address 1531 Esplanade
Aircraft Owner City Chico
Aircraft Owner State CA
Aircraft Owner Country USA
Aircraft Owner Zipcode 95926
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 --
Operator State --
Operator Country --
Operator Zip code --
Operator Code NTQA
Owner has at least one certificate --
Other Operator of large aircraft? --
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) Positioning
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code --
Departure City Chico
Departure State CA
Departure Country USA
Departure Time 1947
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 Landing
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Apr 6 2005 3:09PM
User who most recently changed record COOS
Since inspection or accident Last Inspection
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight Yes
Medical Flight Medical Emergency