Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Twin Falls, Idaho 83301
Sunday, May 20, 2012 9:00 MDT
NTSB Narrative Summary Released at Completion of Accident
The pilot reported that on a previous flight, he encountered an uncommanded roll, so he checked the three main rotor Lamiflex bearings prior to departure. He said one bearing showed no indication of a pending failure, the second showed some indication of approaching failure, and the third showed a minor indication that it was beginning to fail. From past experience, the pilot said that he believed that he still had several hours before the bearings would fail and that he could safely proceed with the flight. A few miles from the intended destination, a vibration started and became progressively worse to the point where the pilot was losing control of the helicopter. The pilot subsequently made what he described as a “controlled crash landing,” which resulted in substantial damage to the helicopter. A postaccident examination revealed that the No. 2 main rotor Lamiflex bearing failed, which resulted in the loss of control. A review of maintenance logbooks found that the helicopter was not in compliance with either its annual inspection requirement or with FAA Airworthiness Directive 94-17-15, which required repetitive inspections of the helicopter’s main rotor Lamiflex bearings.
NTSB Probable Cause Narrative
The pilot's inability to maintain helicopter control during cruise flight due to the failure of the No. 2 main rotor Lamiflex bearing. Contributing to the accident was the pilot's decision to operate the helicopter with a known deficiency and the helicopter’s noncompliance with the mandatory scheduled inspection of the main rotor bearings.
Event Information
| Type of Event | Accident |
| Event Date | 5/20/2012 |
| Event Day of the Week | Sunday |
| Time of Event | 900 |
| Event Time Zone | Mountain Daylight Time |
| Event City | Twin Falls |
| Event State | IDAHO |
| Event Country | -- |
| Zipcode of the event site | 83301 |
| Event Date Year | 2012 |
| Event Date Month | 5 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 422900N |
| Event Location Longitude | 1142900W |
| 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 | 853 Mountain Daylight Time |
| Direction of event from weather observation facility (degrees) | 360 |
| Weather Observation Facility ID | TWF |
| Elevation of weather observation facility | 4154 |
| Distance of event from weather observation facility (units?) | 10 |
| Time Zone of the weather observation | MDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 11000 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Unknown |
| 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) | 16 |
| Dew Point at event time (in degress fahrenheit) | -1 |
| Wind Direction (degrees magnetic) | 350 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 3 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.13 |
| 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) | 31106 |
| NTSB Notification Source | FAA Regional Operations Center |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | May 2 2013 9:03AM |
| User who most recently changed record | johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N63VP |
| NTSB Number | WPR12LA219 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | ENSTROM |
| Aircraft Model | F28 |
| Aircraft Series Identifier | F |
| Aircraft Serial Number | 812 |
| Certified Max Gross Weight | 2600 |
| 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 | 3 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Aug 4 2010 12:00AM |
| Airframe hours since last inspection | 130 |
| Airframe Hours | 1593 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | Michael W. Lattin |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Elko |
| Aircraft Owner State | NV |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 89801 |
| Operator is an individual? | No |
| Operator Name | Michael W. Lattin |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Elko |
| Operator State | NV |
| Operator Country | USA |
| Operator Zip code | 89801 |
| Operator Code | -- |
| Owner has at least one certificate | None |
| Other Operator of large aircraft? | No |
| 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 | EKO |
| Departure City | Elko |
| Departure State | NV |
| Departure Country | USA |
| Departure Time | 615 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | TWF |
| Destination City | Twin Falls |
| Destination State | ID |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Mar 22 2013 12:36PM |
| User who most recently changed record | stam |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | -- |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |