Aircraft Accident/Incident Report

Central, Alaska 99730
Sunday, September 6, 2009 17:35 AKD

NTSB Narrative Summary Released at Completion of Accident

The airline transport helicopter pilot reported that he was on a Title 14, CFR Part 135 passenger flight and was approaching a mountain ridge to drop off two technicians at a radio repeater site. Before beginning his approach, the pilot circled the site to determine the wind conditions, and then began his approach into a 10 knot wind. During the approach to the 5,657 foot level site, the pilot said he encountered a downdraft as the helicopter approached the site, and the helicopter descended below his anticipated approach path. He initiated a go-around, but the helicopter continued to descend, and landed hard, about 150 feet short and down slope of his intended touchdown point. During touchdown, the toes of the helicopter’s skids broke, and the helicopter rocked forward and aft, sustaining substantial damage to the right side of the tail boom. The pilot reported wind conditions on the ground as variable, gusting between 10 and 20 knots. In the pilot’s written statement to the NTSB, he reported that there were no preaccident mechanical problems with the helicopter.

NTSB Probable Cause Narrative

The pilot’s failure to maintain control of the helicopter after an in-flight encounter with a downdraft while landing. Contributing to the accident was the pilot’s inadequate evaluation of wind conditions.

Event Information

Type of Event Accident
Event Date 9/6/2009
Event Day of the Week Sunday
Time of Event 1735
Event Time Zone --
Event City Central
Event State ALASKA
Event Country --
Zipcode of the event site 99730
Event Date Year 2009
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 653426N
Event Location Longitude 1444651W
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 --
Investigator's weather source Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height 2000
Lowest Non-Ceiling Height 2000
Sky/Lowest/Cloud Conditions Thin Broken
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 20
Air Temperature at event time (in degrees celsius) 5
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) 10
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 20
Altimeter Setting at event time (in. Hg) 29.6
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 3
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 26823
NTSB Notification Source FAA ROC
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Apr 15 2010 5:27PM
User who most recently changed record stam
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N4186Y
NTSB Number ANC09LA098
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Company VFR
Flight plan Was Activated? Yes
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name ROBINSON HELICOPTER COMPANY
Aircraft Model R44 II
Aircraft Series Identifier --
Aircraft Serial Number 12533
Certified Max Gross Weight 2500
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats 3
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 Aug 9 2009 12:00AM
Airframe hours since last inspection 41
Airframe Hours 487
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type C126
Aircraft Owner Name ALPINE AIR ALASKA INC
Aircraft Owner Street Address P.O. BOX 519
Aircraft Owner City GIRDWOOD
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99587-0519
Operator is an individual? No
Operator Name ALPINE AIR ALASKA INC
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address P.O. BOX 519
Operator City GIRDWOOD
Operator State AK
Operator Country USA
Operator Zip code 99587-0519
Operator Code --
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation External Load
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Non-scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code FAI
Departure City Fairbanks
Departure State AK
Departure Country USA
Departure Time 1400
Departure Time Zone ADT
Destination Same as Local Flt crash at destination city
Destination Airport Code --
Destination City Central
Destination State AK
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Apr 15 2010 5:27PM
User who most recently changed record stam
Since inspection or accident Time of Accident
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --