Individually Owned: 150,657
Corporate Owned: 137,281
Private Airport
Aircraft Accident/Incident Report
Nelson, Nebraska 68961
Wednesday, August 10, 2011 19:00 CDT
NTSB Narrative Summary Released at Completion of Accident
When the pilot was unable to reduce power normally for landing, he used the fuel cut-off lever to shut down the agricultural airplane's turbine engine. However, the pilot stated that he misjudged the airplane’s altitude and distance to the runway when he shut off fuel to the engine, and the airplane landed short of the runway. During postaccident examination, the fuel control unit failed the manufacturer's functional check. The unit was then disassembled, and the spool cap bearing and its associated hardware, including the cap containing the bearing outer race and the post with the bearing inner race, were found damaged. Metallurgical examination of the bearing races found embedded alumina particles. A historical review of the manufacturer's fuel control unit revealed a history of premature spool cap bearing failures in fuel control units installed on other turboprop engines, but not on the accident airplane’s make and model engine. These failures were attributed to high diamond content and other hard particle contamination and could result in fuel flow and power/torque fluctuations. However, no direct link could be established between the accident-related failure and previous failures in other turboprop engines. Although hard alumina particles were found, there was insufficient historical data to support that these particles had attributed to previous bearing failures in this engine. The cause of the spool cap bearing failure could not be determined.
NTSB Probable Cause Narrative
Failure of the fuel control unit's spool cap bearing for reasons that could not be determined during extensive postaccident examination, and the pilot’s decision to shut the engine down without sufficient altitude and distance to reach the runway.
Event Information
| Type of Event | Accident |
| Event Date | 8/10/2011 |
| Event Day of the Week | Wednesday |
| Time of Event | 1900 |
| Event Time Zone | Central Daylight Time |
| Event City | Nelson |
| Event State | NEBRASKA |
| Event Country | -- |
| Zipcode of the event site | 68961 |
| Event Date Year | 2011 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 401204N |
| Event Location Longitude | 0980400W |
| Event Location Airport | Private |
| Event Location Nearest Airport ID | None |
| 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 | 935 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | HJH |
| Elevation of weather observation facility | 1468 |
| Distance of event from weather observation facility (units?) | 23 |
| Time Zone of the weather observation | CDT |
| Lighting Conditions | Day |
| 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) | 18 |
| Dew Point at event time (in degress fahrenheit) | 16 |
| Wind Direction (degrees magnetic) | 80 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.97 |
| 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 | 1 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 31066 |
| NTSB Notification Source | LINC FSDO |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Feb 27 2013 2:49PM |
| User who most recently changed record | yeal |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N3659N |
| NTSB Number | CEN11LA566 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 137: Agricultural |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | AIR TRACTOR INC |
| Aircraft Model | AT-400 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 400-0294 |
| Certified Max Gross Weight | 7860 |
| 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 | 1 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Dec 5 2010 12:00AM |
| Airframe hours since last inspection | 197 |
| Airframe Hours | 3900 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | WEHRMAN JIM |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | NELSON |
| Aircraft Owner State | NE |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 68961-8107 |
| Operator is an individual? | No |
| Operator Name | WEHRMAN JIM |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | NELSON |
| Operator State | NE |
| Operator Country | USA |
| Operator Zip code | 68961-8107 |
| Operator Code | -- |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Agriculture |
| 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) | Aerial Application |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | None |
| Departure City | Private |
| Departure State | NE |
| Departure Country | USA |
| Departure Time | 1830 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | None |
| Destination City | Private |
| Destination State | NE |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 27 2013 2:51PM |
| User who most recently changed record | yeal |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | -- |
| Air Medical Flight | -- |
| Medical Flight | -- |