Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Acworth, Georgia 30101
Wednesday, August 12, 2009 10:00 EDT
NTSB Narrative Summary Released at Completion of Accident
The pilot stated that he and an observer were conducting an aerial observation when during the descent he heard a loud noise. Subsequently, he received an "ENG OUT" audio and caution lights, and made an emergency autorotation into a field. An examination of the engine’s turbine section revealed rub marks throughout the turbine section consistent with an out-of-balance condition caused by a third-stage turbine airfoil release. The third-stage wheel airfoil fractured in fatigue near the root of the airfoil and no anomalies were found at the fatigue origin. The fracture surface of the failed third-stage blade revealed high-cycle fatigue failure over an extended period of time. The crack propagation is estimated to be greater than 2000 cycles. No additional cracks were found on the other third-stage wheel airfoils.
Review of the logbook revealed that the airframe engine total time was 3,820 hours and the engine had gone through a 100- and 300-hour inspection at 3,809.6 engine hours. All airworthiness directives and applicable service bulletins as well as all instructions for continued airworthiness were complied with. The hot section and turbine inspection was completed on February 21, 2008, at 2,958 hours. The third-stage turbine wheel was overhauled on February 3, 2004, at 1210.6 hours and 1633.0 cycles and was due to be replaced at 4,710.6 hours. At the time of the accident the wheel had 2609.7 hours and 2412.0 cycles.
NTSB Probable Cause Narrative
The loss of engine power due to the fatigue failure of the third-stage turbine wheel airfoil.
Event Information
| Type of Event | Accident |
| Event Date | 8/12/2009 |
| Event Day of the Week | Wednesday |
| Time of Event | 1000 |
| Event Time Zone | Eastern Daylight Time |
| Event City | Acworth |
| Event State | GEORGIA |
| Event Country | -- |
| Zipcode of the event site | 30101 |
| Event Date Year | 2009 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 340358N |
| Event Location Longitude | 0844036W |
| 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 | 847 Eastern Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | RYY |
| Elevation of weather observation facility | 1040 |
| Distance of event from weather observation facility (units?) | 5 |
| Time Zone of the weather observation | EDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 11000 |
| Lowest Non-Ceiling Height | 4000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| 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) | 27 |
| Dew Point at event time (in degress fahrenheit) | 21 |
| Wind Direction (degrees magnetic) | 330 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 5 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.03 |
| 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 | 1 |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 2 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 27827 |
| NTSB Notification Source | FAA Southern ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Nov 23 2010 2:01PM |
| User who most recently changed record | kenj |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N527BB |
| NTSB Number | ERA09LA460 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 91: General Aviation |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | MCDONNELL DOUGLAS HELICOPTER |
| Aircraft Model | 369E |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 0329E |
| Certified Max Gross Weight | 3100 |
| 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 | 4 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Aug 1 2009 12:00AM |
| Airframe hours since last inspection | 10 |
| Airframe Hours | 4257 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | C91 |
| Aircraft Owner Name | ROTORWORKS LLC |
| Aircraft Owner Street Address | 165 COMMODORE PATH |
| Aircraft Owner City | HIRAM |
| Aircraft Owner State | GA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 30141 |
| Operator is an individual? | No |
| Operator Name | ROTORWORKS LLC |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | 165 COMMODORE PATH |
| Operator City | HIRAM |
| Operator State | GA |
| Operator Country | USA |
| Operator Zip code | 30141 |
| Operator Code | -- |
| Owner has at least one certificate | Yes - certificate holder |
| 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) | Aerial Observation |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | RYY |
| Departure City | Acworth |
| Departure State | GA |
| Departure Country | USA |
| Departure Time | 900 |
| Departure Time Zone | EDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | RYY |
| Destination City | Acworth |
| Destination State | GA |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Nov 23 2010 2:01PM |
| User who most recently changed record | kenj |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |