Aircraft Accident/Incident Report

Ft Yukon, Alaska 99740
Friday, September 30, 2005 12:10 AKD

NTSB Narrative Summary Released at Completion of Accident

The flight crew, an airline transport certificated captain, and a commercial certificated co-pilot, were flying a restricted category, icing research equipped airplane in instrument meteorological icing conditions under Title 14, CFR Part 91. The purpose of the flight was to locate icing conditions for a prototype helicopter's in-flight icing tests. While in cruise flight, the airplane encountered icing conditions, and had accumulated about 1" of ice on the leading edges of the wings. The captain reported that he activated the wing deicing pneumatic boots, and the ice was shed from both wings. About 4 minutes after activating the deice boots, both engines simultaneously lost all power. The crew attempted several engine restarts, but were unsuccessful, and made a forced landing on frozen, snow-covered terrain. During the landing, the airplane struck several small, burned trees, and sustained substantial damage. The airplane's ice control system is comprised of two separate systems, one an anti-ice, the other, a deice. The majority of the wings' surfaces are deiced by pneumatic, inflating boots. The inboard section of the wings, directly in front of the engine air inlets, and the engine air inlets themselves, utilize a heated, anti-ice surface to preclude any ice accretion and potential for ice ingestion into the engines. The anti-ice system is not automatic, and must be activated by the flight crew prior to entering icing conditions. A researcher in the aft cabin photographed the airplane's wings before and after the activation of the deice boots. The photographs taken prior to the deice boot activation depicted about 1" of ice on the wings, as well as on the anti-ice (heated) inboard portion of the wings. The photographs taken after the deice boot activation revealed that the ice had been removed from the booted portion of the wings, but ice remained on the inboard, anti-ice segment. An engineer from the airplane's manufacturer said that if the anti-ice system was activated after ice had accumulated on the wings, it would take 2-4 minutes for the anti-ice portion of the wings and engine inlets to heat sufficiently to shed the ice. A postaccident inspection of the anti-ice components found no anomalies, and there was no record of any recent problems with the anti-ice system. The flight crew reported that the anti-ice activation switch is on the captain's side, and they could not recall if or when the anti-ice system was activated. They stated that they did not discuss its use, or use a checklist that addressed the use of the anti-ice system. A section of the airplane's flight manual states: "Failure to switch on the [anti-ice] system before ice accumulation has begun may result in engine damage due to ice ingestion." An inspection by an NTSB power plant engineer disclosed catastrophic engine damage consistent with ice ingestion.

NTSB Probable Cause Narrative

The pilot's improper use of anti-icing equipment during cruise flight, which resulted in ice ingestion into both engines (foreign object damage), the complete loss of engine power in both engines, and an emergency descent and landing on tree covered terrain. Factors associated with the accident were the icing conditions, inadequate crew resource management, and failure to use a checklist.

Event Information

Type of Event Accident
Event Date 9/30/2005
Event Day of the Week Friday
Time of Event 1210
Event Time Zone --
Event City Ft Yukon
Event State ALASKA
Event Country --
Zipcode of the event site 99740
Event Date Year 2005
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 663319N
Event Location Longitude 1472859W
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 --
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling Obscured
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 0.1
Air Temperature at event time (in degrees celsius) --
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) --
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 4
Injury Total None --
Injury Total Serious --
Injury Total All 4
Investigating Agency NTSB
NTSB Docket Number (internal use) 21060
NTSB Notification Source FAA Anchorage, ROC
NTSB Notification Date Sep 30 2005 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Feb 26 2007 11:14AM
User who most recently changed record NTSB\lema
Basic weather conditions Instrument Meteorological Cond
FAA District Office Fairbanks FSDO-01

Aircraft Involved

Aircraft #1

Aircraft Registration Number N77ND
NTSB Number ANC05LA150
Missing Aircraft Indicator Y
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 550
Aircraft Series Identifier --
Aircraft Serial Number 550-0005
Certified Max Gross Weight 14700
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 5
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Jun 1 2005 12:00AM
Airframe hours since last inspection --
Airframe Hours 4262
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site Yes
ELT Type --
Aircraft Owner Name University of North Dakota
Aircraft Owner Street Address Box 8216 University Station
Aircraft Owner City Grand Forks
Aircraft Owner State ND
Aircraft Owner Country USA
Aircraft Owner Zipcode 58202
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 --
Owner has at least one certificate None
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) Other Work Use
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code PAFA
Departure City Fairbanks
Departure State AK
Departure Country USA
Departure Time 1055
Departure Time Zone ADT
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 Emergency landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 8 2007 1:50PM
User who most recently changed record LABJ
Since inspection or accident Last Inspection
Event Location Runway Number and Location NA
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --