Individually Owned: 150,657
Corporate Owned: 137,281
None Airport
Aircraft Accident/Incident Report
Danville, West Virginia 25053
Saturday, July 15, 2006 9:15 EDT
NTSB Narrative Summary Released at Completion of Accident
Approximately 7 minutes after takeoff, the pilot of the helicopter heard a "loud snap," and experienced a 5 to 10 degree right yaw. This occurred a second time, 5 to 8 seconds later. The pilot declared an emergency and elected to make a precautionary landing. During the approach, he experienced a third snap sound and yaw movement. The helicopter was at an airspeed below 20 knots, and about 8 to 10 feet above the ground, when the pilot heard a bang, and felt ground contact. The helicopter rolled to the left, and the main rotor blades contacted the ground. Examination of the helicopter confirmed drive train continuity to the main and tail rotor drive shafts. A ground scar, consistent with tail rotor ground contact, was observed about 60 feet from the main wreckage. The tail rotor gear box, drive shaft and blade assembly were located about 250 feet from the main wreckage. Examination of the tail rotor gearbox and adjacent components did not reveal any preexisting damage; however, it also did not reveal any indications of rotational damage. Examination of the override clutch assembly, which drove both the main transmission and the tail rotor system, revealed preexisting damage that occurred at an undeterminable time prior to the accident. The accident helicopter was involved in a previous hard landing accident about 13 months, and 87 hours of operation prior, during which, it had a tail rotor strike, and a fractured tail rotor drive shaft. The override clutch assembly was not removed for inspection after that accident; nor was it specifically required to be removed and inspected per the manufacturer's maintenance guidelines for "Special Inspection for Sudden Stoppage, Main and/or Tail Rotor Blade Strikes."
NTSB Probable Cause Narrative
A partial failure of the override clutch assembly. A contributing factor to the accident was the manufacturer's inadequate inspection procedures of the override clutch assembly following a tail rotor strike.
Event Information
| Type of Event | Accident |
| Event Date | 7/15/2006 |
| Event Day of the Week | Saturday |
| Time of Event | 915 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Danville |
| Event State | WEST VIRGINIA |
| Event Country | -- |
| Zipcode of the event site | 25053 |
| Event Date Year | 2006 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 380500N |
| Event Location Longitude | 0805020W |
| Event Location Airport | NONE |
| 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 | 954 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 30 |
| Weather Observation Facility ID | CRW |
| Elevation of weather observation facility | 981 |
| Distance of event from weather observation facility (units?) | 24 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 1500 |
| Lowest Non-Ceiling Height | 800 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 7 |
| Air Temperature at event time (in degrees celsius) | 24 |
| Dew Point at event time (in degress fahrenheit) | 21 |
| Wind Direction (degrees magnetic) | 250 |
| 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 | Minor |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | 1 |
| Injury Total None | -- |
| Injury Total Serious | -- |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 23382 |
| NTSB Notification Source | FAA EROC |
| NTSB Notification Date | Jul 18 2006 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Apr 30 2008 1:28PM |
| User who most recently changed record | NTSB\johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Charleston |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N5691B |
| NTSB Number | NYC06LA175 |
| 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 | 280C |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 1180 |
| Certified Max Gross Weight | 2350 |
| 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 | 100 Hour |
| Date of Last Inspection | Jun 1 2006 12:00AM |
| Airframe hours since last inspection | 11 |
| Airframe Hours | 1804 |
| ELT Installed | No |
| ELT Activated | -- |
| ELT Aided Location of Event Site | -- |
| ELT Type | -- |
| Aircraft Owner Name | Marpat Aviation LLC |
| Aircraft Owner Street Address | P.O. Box 161 |
| Aircraft Owner City | Switzer |
| Aircraft Owner State | WV |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 25647 |
| 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) | Instructional |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | 6L4 |
| Departure City | Logan |
| Departure State | WV |
| Departure Country | USA |
| Departure Time | 905 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | PMH |
| Destination City | Portsmouth |
| Destination State | OH |
| Destination Country | USA |
| Specific Phase of Flight | Landing |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Mar 28 2008 11:13PM |
| User who most recently changed record | MUZD |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |