Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Fresno, California 93622
Monday, June 23, 2008 7:00 PDT
NTSB Narrative Summary Released at Completion of Accident
The pilot reported that he had filled the spray tanks with water and had lifted off from a platform on the back of a truck when he heard three loud noises followed by a loss of engine power. The pilot initiated a hovering autorotation to the landing platform; however, was only able to maneuver the forward portion of the helicopter over the platform. Subsequently, the helicopter slid off the platform and impacted the ground tail boom first, resulting in structural damage to the tail boom and fuselage. Examination of the engine revealed that 15 third stage compressor vanes were fractured near the root and had separated. The majority of the separated vanes were located in the lower compressor case half. The remaining attached vanes were bent over in the direction of engine rotation. A single second stage compressor vane located in the lower case halve was fractured near the root and had liberated. Multiple third and fourth stage compressor blades had leading edge damage. One second stage vane airfoil was separated and the area of separation was found consistent with high cycle fatigue (HCF). An additional second stage vane airfoil exhibited a crack, consistent with HCF near the root, but it did not separate. A Semi-quantitative x-ray energy dispersive analysis (XEDA) revealed deposits at the suction side vane root were consistent with oxidized braze alloy, indicating the braze alloy was exposed during engine operation. It was also found that the chemistry, microstructure and hardness of the second stage vanes were consistent with component specifications.
NTSB Probable Cause Narrative
The loss of engine power due to fatigue failure of a second stage compressor blade.
Event Information
| Type of Event | Accident |
| Event Date | 6/23/2008 |
| Event Day of the Week | Monday |
| Time of Event | 700 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Fresno |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93622 |
| Event Date Year | 2008 |
| Event Date Month | 6 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 364634N |
| Event Location Longitude | 1194305W |
| 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 | 953 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | KFAT |
| Elevation of weather observation facility | 336 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 20000 |
| Sky/Lowest/Cloud Conditions | Scattered |
| Sky Condition for Lowest Ceiling | None |
| Visibility Runway Visual Range (Feet) | -- |
| Visibility Runway Visual Value (Statute Miles) | -- |
| Visibility (Statute Miles) | 5 |
| Air Temperature at event time (in degrees celsius) | 26 |
| Dew Point at event time (in degress fahrenheit) | 2 |
| Wind Direction (degrees magnetic) | 280 |
| 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) | 29.95 |
| 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) | 24874 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jun 23 2008 12:00AM |
| NTSB Notification Time | -- |
| Fiche Number and/or location -used to find docket information | -- |
| Date of most recent change to record | Jan 26 2009 10:03AM |
| User who most recently changed record | grol |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | Fresno, California |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N912HP |
| NTSB Number | LAX08LA195 |
| Missing Aircraft Indicator | -- |
| Federal Aviation Reg. Part | Part 137: Agricultural |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | No |
| Damage | Substantial |
| Aircraft Fire | None |
| Aircraft Explosion | None |
| Aircraft Manufacturer's Full Name | Arrow Falcon Exporters, Inc. |
| Aircraft Model | OH-58C |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 71-20679 |
| Certified Max Gross Weight | 3200 |
| 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 | 2 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Jan 17 2008 12:00AM |
| Airframe hours since last inspection | 20.5 |
| Airframe Hours | 5047.3 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Del Rio Aviation |
| Aircraft Owner Street Address | 5062 Wing Way |
| Aircraft Owner City | Paso Robles |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 93446 |
| Operator is an individual? | No |
| Operator Name | Double Tree Helicopters |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | 519 East Greenway Avenue |
| Operator City | Turlock |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | 95380 |
| Operator Code | -- |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | Agriculture |
| 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 Application |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | -- |
| Departure City | Fresno |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 1042 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | USA |
| Specific Phase of Flight | Hover |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Dec 31 2008 4:50PM |
| User who most recently changed record | stam |
| 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 | -- |