Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Leverett, Massachusetts 01054
Sunday, December 5, 2010 15:30 EST
NTSB Narrative Summary Released at Completion of Accident
The airplane was in cruise flight at 3,000 feet above ground level when the engine developed vibrations and, shortly after, lost total power. The pilot conducted a forced landing in an open field. The pilot cleared the trees adjacent to the field but did not see the electrical wires on the other side. The airplane’s main landing gear contacted the wires, and the airplane flipped and impacted the ground inverted. Examination of the engine revealed that several incorrect nuts for the cylinder hold-down studs were installed, and the breakaway torque values measured for the cylinder hold-down nuts were consistent with improper torque having been applied. Metallurgical examination revealed that the engine’s crankshaft fractured due to fatigue cracks that developed as a result of the No. 2 main bearing shifting in the crankcase saddle. The through-bolts that clamp the No. 2 crankcase saddle faces are secured with the hold-down nuts for the Nos. 2 and 3 cylinders. The engine had a reported total time in service of 6,629 hours with 1,475 hours since major overhaul. All six cylinders had been replaced since the overhaul, with the Nos. 2 and 3 cylinders having been replaced 692 and 549 hours before the accident, respectively.
NTSB Probable Cause Narrative
A total loss of engine power due to the fatigue failure of the crankshaft, which resulted from improper tightening of the cylinder hold-down nuts.
Event Information
| Type of Event | Accident |
| Event Date | 12/5/2010 |
| Event Day of the Week | Sunday |
| Time of Event | 1530 |
| Event Time Zone | Eastern Standard Time |
| Event City | Leverett |
| Event State | MASSACHUSETTS |
| Event Country | -- |
| Zipcode of the event site | 01054 |
| Event Date Year | 2010 |
| Event Date Month | 12 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 422639N |
| Event Location Longitude | 0722931W |
| 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 | 1552 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 45 |
| Weather Observation Facility ID | ORE |
| Elevation of weather observation facility | 555 |
| Distance of event from weather observation facility (units?) | 13 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 4200 |
| Lowest Non-Ceiling Height | -- |
| Sky/Lowest/Cloud Conditions | Unknown |
| 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) | -2 |
| Dew Point at event time (in degress fahrenheit) | -10 |
| Wind Direction (degrees magnetic) | 310 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 9 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Gusting |
| Wind Gust (knots) | 15 |
| Altimeter Setting at event time (in. Hg) | 29.52 |
| 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 | 2 |
| Injury Total All | 4 |
| Investigating Agency | -- |
| NTSB Docket Number (internal use) | 29494 |
| NTSB Notification Source | FAA New England ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Dec 15 2011 12:28PM |
| User who most recently changed record | kenj |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N9742Z |
| NTSB Number | ERA11FA078 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | VFR |
| Flight plan Was Activated? | Yes |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | CESSNA |
| Aircraft Model | U206G |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | U20606636 |
| Certified Max Gross Weight | 3600 |
| Aircraft Category | Airplane |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | 1 |
| Cabin Crew Seats | -- |
| Passenger Seats | 5 |
| Total number of seats on the aircraft | 6 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Oct 25 2010 12:00AM |
| Airframe hours since last inspection | 15 |
| Airframe Hours | 6572 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91-A |
| Aircraft Owner Name | AIRBORNE MAINTENANCE INC |
| Aircraft Owner Street Address | 90 ARRIVAL AVE STE 20 |
| Aircraft Owner City | RONKONKOMA |
| Aircraft Owner State | NY |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 11779-7361 |
| Operator is an individual? | Yes |
| Operator Name | Individual |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | New York |
| Operator State | NY |
| Operator Country | USA |
| Operator Zip code | 11779-7361 |
| 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 | Yes |
| Departure Point Same as Event | No |
| Departure Airport Code | EEN |
| Departure City | Keene |
| Departure State | NH |
| Departure Country | USA |
| Departure Time | 1515 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | -- |
| Destination Airport Code | ISP |
| Destination City | Islip |
| Destination State | NY |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Dec 15 2011 12:28PM |
| User who most recently changed record | kenj |
| 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 | -- |