Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Arvilla, North Dakota 58214
Sunday, September 6, 2009 8:05 CDT
NTSB Narrative Summary Released at Completion of Accident
The helicopter pilot reported that he heard a “crack” and a “bang” when he pulled up at the end of the field during the spray run. He stated the helicopter began spinning to the right as it gained altitude. He rolled off the throttle and was able to clear a row of trees at the end of the field. The helicopter impacted the terrain on one side of the tree line and the tail boom was located approximately 100 feet away, on the other side of the tree line. The examination revealed the tail boom’s upper left attach fitting contained fatigue fractures that originated at the upper and lower rivet holes. Corrosion was also present along the fractured surface. The tail boom’s upper right attachment bolt contained a fatigue fracture which had multiple origins. The tail boom’s lower right attach fitting fractured as a result of overload. The tail boom involved in this accident was installed on the helicopter on February 20, 2006, and had been removed from a UH-1F helicopter. The UH-1F tail boom is 23.8 inches longer than the UH-1B tail boom that was originally on the helicopter. The pilot/owner, who is an airframe and powerplant mechanic with inspection authority, performed this maintenance. There is no load data nor is there a Supplemental Type Certificate available for this installation.
NTSB Probable Cause Narrative
The aircraft owner/mechanic/pilot's installation of an improper tail boom assembly and the resulting fatigue failure of the tail boom's attach fittings.
Event Information
| Type of Event | Accident |
| Event Date | 9/6/2009 |
| Event Day of the Week | Sunday |
| Time of Event | 805 |
| Event Time Zone | Central Daylight Time |
| Event City | Arvilla |
| Event State | NORTH DAKOTA |
| Event Country | -- |
| Zipcode of the event site | 58214 |
| Event Date Year | 2009 |
| Event Date Month | 9 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 475504N |
| Event Location Longitude | 0972940W |
| 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 | Unknown |
| Time of the weather observation | 755 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | 45 |
| Weather Observation Facility ID | GFK |
| Elevation of weather observation facility | 845 |
| Distance of event from weather observation facility (units?) | 6 |
| 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) | 7 |
| Air Temperature at event time (in degrees celsius) | 16 |
| Dew Point at event time (in degress fahrenheit) | 15 |
| Wind Direction (degrees magnetic) | 180 |
| 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) | 30.06 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 26419 |
| NTSB Notification Source | FAA-FAR-FSDO |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 14 2009 10:49AM |
| User who most recently changed record | bowl |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N204JB |
| NTSB Number | CEN09LA565 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 137: Agricultural |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | BELL |
| Aircraft Model | UH-1B |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 63-13088 |
| Certified Max Gross Weight | -- |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Feb 6 2009 12:00AM |
| Airframe hours since last inspection | 17 |
| Airframe Hours | 9587 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | MORTEN JESSE L |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | LARIMORE |
| Aircraft Owner State | ND |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 58251-9616 |
| Operator is an individual? | No |
| Operator Name | MORTEN JESSE L |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | LARIMORE |
| Operator State | ND |
| Operator Country | USA |
| Operator Zip code | 58251-9616 |
| 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 | 62ND |
| Departure City | Larimore |
| Departure State | ND |
| Departure Country | USA |
| Departure Time | -- |
| Departure Time Zone | -- |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 20 2009 4:15PM |
| User who most recently changed record | sulp |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |