Aircraft Accident/Incident Report

Ekalaka, Montana 59324
Sunday, October 7, 2007 11:48 MDT

NTSB Narrative Summary Released at Completion of Accident

The instrument-rated private pilot was on a cross-country flight in instrument meteorological conditions. About 40 minutes after departure the pilot reported to air traffic control (ATC) that he was encountering icing conditions at his cruise altitude of 13,000 feet and requested a lower altitude. The pilot was cleared to descend to 11,000 feet. The pilot continued to encounter icing conditions and was cleared to descend to lower altitudes. About 15 minutes after the pilot's initial report of icing conditions, he transmitted "headed towards the runway" followed by "...going down...troubles with engine." No additional communication from the accident pilot was received. The wreckage was located later that day in an open field about 2 miles west of a private airstrip. Post accident examination of the airframe and engine revealed no evidence of mechanical malfunction or anomaly. Ground scars and wreckage signatures were consistent with a stall/mush into the terrain. Weather forecasts and pilot reports for the pilot's intended route of flight indicated icing and widespread instrument meteorological conditions. The pilot received a weather briefing prior to the flight; however, it was limited by his request to wind, temperature aloft forecasts and METAR observations for his route of flight. FAA Advisory Circular 91-51A states, in part, "The most hazardous aspect of structural icing is its aerodynamic effects. Ice can alter the shape of an airfoil. This can cause control problems, change the angle of attack at which the aircraft stalls, and cause the aircraft to stall at a significantly higher airspeed..." The AC additionally states "Flight into known or potential icing situations without thorough knowledge of icing and its effects and appropriate training and experience in use of deice and anti-ice systems should be avoided." According to the manufacturer, the airplane was not certified or equipped for flight into known icing conditions. It is probable that the airplane was unable to maintain an adequate airspeed during the descent for landing and stalled short of the runway.

NTSB Probable Cause Narrative

The pilot's improper in-flight planning/decision, his continued flight into adverse weather (icing conditions), and failure to maintain an adequate airspeed during the emergency descent for landing. Contributing to the accident were the forecast icing conditions.

Event Information

Type of Event Accident
Event Date 10/7/2007
Event Day of the Week Sunday
Time of Event 1148
Event Time Zone Mountain Daylight Time
Event City Ekalaka
Event State MONTANA
Event Country --
Zipcode of the event site 59324
Event Date Year 2007
Event Date Month 10
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 454109N
Event Location Longitude 1044501W
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 Weather Observation Facility
Time of the weather observation 1153 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 35
Weather Observation Facility ID KBHK
Elevation of weather observation facility 2975
Distance of event from weather observation facility (units?) 43
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height 9500
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 7
Dew Point at event time (in degress fahrenheit) 2
Wind Direction (degrees magnetic) 240
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 7
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.07
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 2
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 2
Investigating Agency NTSB
NTSB Docket Number (internal use) 24370
NTSB Notification Source FAA-ROC
NTSB Notification Date Oct 7 2007 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Sep 26 2008 6:40PM
User who most recently changed record NTSB\lema
Basic weather conditions Visual Meteorological Cond
FAA District Office Helena, Montana

Aircraft Involved

Aircraft #1

Aircraft Registration Number N85WT
NTSB Number SEA08FA006
Missing Aircraft Indicator --
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 Ground
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 310N
Aircraft Series Identifier --
Aircraft Serial Number 310N-0106
Certified Max Gross Weight 5200
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 4
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jul 1 2007 12:00AM
Airframe hours since last inspection --
Airframe Hours 4472
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name John R. Doshier
Aircraft Owner Street Address --
Aircraft Owner City Baltimore
Aircraft Owner State MT
Aircraft Owner Country USA
Aircraft Owner Zipcode 21202
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) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code BZN
Departure City BOZEMAN
Departure State MT
Departure Country USA
Departure Time 1002
Departure Time Zone MDT
Destination Same as Local Flt --
Destination Airport Code C85
Destination City BARABOO
Destination State WI
Destination Country USA
Specific Phase of Flight Landing
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Sep 19 2008 8:09PM
User who most recently changed record STAM
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 --