Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Alva, Oklahoma 73717
Friday, March 30, 2012 9:43 CDT
NTSB Narrative Summary Released at Completion of Accident
The helicopter was flying at 300 feet above the ground with an external load when the pilot heard a loud noise from the engine and the rotor rpm began to decay. He jettisoned the load and entered an autorotation. During the flare, the helicopter's main rotor blades contacted the tail rotor drive shaft. Engine disassembly and examination revealed that the turbine casing was deeply eroded by particles that had accumulated in the casing as a result of operating in dusty environments. The erosion caused a crack to develop, and non-uniform overheating of the engine led to the partial melting of the nozzle guide vanes and the rupture of the blade tips in all three turbine stages. Uncontained debris then punctured the turbine casing and shroud. According to the helicopter's maintenance records, the helicopter had operated 68 hours past a 100-hour inspection. The erosion in the engine was likely preexisting since it had been purchased second hand. Further, the records contained no entries pertaining to compliance with the manufacturer's maintenance procedures, by either the current or previous owner, for operations in sandy environments. The current operator reported that they have since complied with the manufacturer’s procedures.
NTSB Probable Cause Narrative
Failure of the current and previous operators to comply with the manufacturer's maintenance procedures for operation in sandy environments, which resulted in turbine case erosion and the subsequent uncontained engine failure.
Event Information
| Type of Event | Accident |
| Event Date | 3/30/2012 |
| Event Day of the Week | Friday |
| Time of Event | 943 |
| Event Time Zone | Central Daylight Time |
| Event City | Alva |
| Event State | OKLAHOMA |
| Event Country | -- |
| Zipcode of the event site | 73717 |
| Event Date Year | 2012 |
| Event Date Month | 3 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 373011N |
| Event Location Longitude | 0990035W |
| 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 | 850 Central Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | -- |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| 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) | -- |
| Dew Point at event time (in degress fahrenheit) | -- |
| Wind Direction (degrees magnetic) | 210 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 2 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | -- |
| 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) | 30771 |
| NTSB Notification Source | FAA ASW ROC |
| NTSB Notification Date | -- |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 25 2013 8:40AM |
| User who most recently changed record | johb |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N929JV |
| NTSB Number | CEN12LA235 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 133: Rotorcraft Ext. Load |
| Type of Flight Plan filed | Unknown |
| Flight plan Was Activated? | -- |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Eurocopter |
| Aircraft Model | SA315B |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 2361 |
| Certified Max Gross Weight | 5070 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | 1 |
| Cabin Crew Seats | -- |
| Passenger Seats | 4 |
| Total number of seats on the aircraft | 5 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Mar 23 2012 12:00AM |
| Airframe hours since last inspection | 164 |
| Airframe Hours | 12160 |
| ELT Installed | Yes |
| ELT Activated | No |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | Unknown |
| Aircraft Owner Name | Roberts Aircraft Company |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Cheyenne |
| Aircraft Owner State | WY |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 82001-1469 |
| Operator is an individual? | No |
| Operator Name | Trans Aero, Ltd. |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Loveland |
| Operator State | CO |
| Operator Country | USA |
| Operator Zip code | 80538 |
| Operator Code | 868K |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | External Load |
| 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) | External Load |
| Second Pilot on Board | No |
| Departure Point Same as Event | No |
| Departure Airport Code | KAVK |
| Departure City | Alva |
| Departure State | OK |
| Departure Country | USA |
| Departure Time | 830 |
| Departure Time Zone | CDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | KAVK |
| Destination City | Alva |
| Destination State | OK |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Oct 26 2012 4:27PM |
| User who most recently changed record | scoa |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | N/A |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |