Aircraft Accident/Incident Report

Ketchikan, Alaska 99901
Monday, July 21, 2003 9:00 AKD

NTSB Narrative Summary Released at Completion of Accident

The commercial certificated pilot was conducting an on-demand air taxi flight in a turbine-powered helicopter. While performing an aerial survey, about 100 feet agl, the engine-out annunciator sounded, and the pilot entered an autorotation. As the helicopter touched down in a small clearing, the pilot had the collective pitch control full up to cushion the landing. When the helicopter touched down, the engine power suddenly surged, and the helicopter then began to climb. During the pilot's efforts to control the helicopter, the main rotor blades collided with several trees, and the blades then severed the tail boom. Following the collision with the trees, the pilot rolled the throttle to the off position, but the engine would not shut-down. He then pulled the emergency fuel shut off. Examintion of the helicopter revealed that a bolt, used to connect the N2 governor input arm to an airframe mounted bellcrank, was missing. The bellcrank is connected to the helicopter's collective control linkage. As the pilot moves the collective control, through the bellcrank and governor input arm, engine power increases or decreases. The bolt is normally retained by a castellated nut, and then secured in-place by a cotter pin. Company personnel returned to the accident scene and located the missing bolt and nut lying on the ground, under the location where the engine access doors were opened during an inspection of the engine, before the helicopter was removed from the accident scene. Also found was a cotter pin with one broken side, but it could not be determined if the broken cotter pin was the missing pin from the bolt. The most recent inspection of the helicopter was a 100 hour inspection, conducted by company personnel, 51.8 service hours before the accident. Numerous company pilots had flown the helicopter before the accident. In addition, each pilot conducted an inspection of the helicopter before beginning flight operations. On the day of the accident, the helicopter had flown about 2.5 hours before the accident.

NTSB Probable Cause Narrative

The improper installation of a bolt in the gas generator governor linkage by company maintenance personnel, which resulted in a loss of the bolt, a loss of engine power while maneuvering, and subsequent forced landing and collision with trees. Factors contributing to the accident were an inadequate preflight inspection by the pilot, and an uncommanded surge in engine power.

Event Information

Type of Event Accident
Event Date 7/21/2003
Event Day of the Week Monday
Time of Event 900
Event Time Zone --
Event City KETCHIKAN
Event State ALASKA
Event Country --
Zipcode of the event site 99901
Event Date Year 2003
Event Date Month 7
MidAir Collision Indicator --
On Ground Collision occurred ? --
Event Location Latitude 555210N
Event Location Longitude 1312756W
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 Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 853 Atlantic Daylight Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID PAKT
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation ADT
Lighting Conditions Day
Lowest Ceiling Height 2800
Lowest Non-Ceiling Height 1200
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 14
Dew Point at event time (in degress fahrenheit) 13
Wind Direction (degrees magnetic) 115
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 10
Wind Velocity Indicator --
Wind Gust Indicator Gusting
Wind Gust (knots) 16
Altimeter Setting at event time (in. Hg) 30.1
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor 1
Injury Total None 2
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 14694
NTSB Notification Source TEMSCO HELICOPTERS
NTSB Notification Date Jul 21 2003 12:00AM
NTSB Notification Time 1110
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Feb 5 2004 4:26PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office FAA-AL-JNU FSDO 05

Aircraft Involved

Aircraft #1

Aircraft Registration Number N1091S
NTSB Number ANC03LA082
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 135: Air Taxi & Commuter
Type of Flight Plan filed Company VFR
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Hughes
Aircraft Model 369D
Aircraft Series Identifier --
Aircraft Serial Number 300691D
Certified Max Gross Weight 3000
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 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Jul 8 2003 12:00AM
Airframe hours since last inspection 52
Airframe Hours 9553
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name TEMSCO HELICOPTERS INC.
Aircraft Owner Street Address P.O. BOX 5057
Aircraft Owner City KETCHIKAN
Aircraft Owner State AK
Aircraft Owner Country USA
Aircraft Owner Zipcode 99901
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 HXS0
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation Agriculture
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 Yes
Departure Airport Code 17AK
Departure City KETCHIKAN
Departure State AK
Departure Country USA
Departure Time 830
Departure Time Zone ADT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City KETCHIKAN
Destination State AK
Destination Country USA
Specific Phase of Flight Emergency descent/landing
Report sent to ICAO? No
Evacuation occurred Yes
Date of most recent change to record Nov 20 2003 2:38PM
User who most recently changed record PETL
Since inspection or accident Last Inspection
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --