Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Bakersfield, California 93206
Saturday, April 3, 2004 7:45 PST
NTSB Narrative Summary Released at Completion of Accident
The helicopter experienced a loss of tail rotor control and collided with terrain. During an aerial application flight, the pilot heard a rattling noise from the aft end of the helicopter. He then lost tail rotor authority and entered a flat spin. The pilot attempted to make a run-on landing, but the helicopter continued to spin until it impacted terrain. A Federal Aviation Administration inspector examined the helicopter after the accident. He noted that the cross-over support tube near the aft end of the tail boom was missing. A crack was found on the tail boom left side frame tubes. Deposits of rust in the area suggests that the crack was a pre-existing crack. The inspector thought that this would have added excessive stress to the structure during turning maneuvers and caused the last spline coupling shaft to disconnect from the tail rotor gear box as the tail boom flexed. A 50-hour maintenance inspection was completed the day before the accident.
NTSB Probable Cause Narrative
a loss of tail rotor drive due to a disconnection of the drive shaft's splined coupling at the tail rotor gear box. The splined coupling to tail rotor gear box disconnection occurred as a result of tail boom flexing due to the combined effects of an uninstalled structural support tube and a crack in left side frame tubes. Inadequate maintenance inspection was a factor.
Event Information
| Type of Event | Accident |
| Event Date | 4/3/2004 |
| Event Day of the Week | Saturday |
| Time of Event | 745 |
| Event Time Zone | Pacific Standard Time |
| Event City | Bakersfield |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93206 |
| Event Date Year | 2004 |
| Event Date Month | 4 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 352100N |
| Event Location Longitude | 1190000W |
| 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 | Not pertinent |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 754 Pacific Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | BFL |
| Elevation of weather observation facility | 497 |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | PST |
| 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) | 10 |
| Air Temperature at event time (in degrees celsius) | 17 |
| Dew Point at event time (in degress fahrenheit) | 6 |
| Wind Direction (degrees magnetic) | 0 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 0 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.93 |
| Density Altitude (feet) | 843 |
| 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 | -- |
| Injury Total None | -- |
| Injury Total Serious | 1 |
| Injury Total All | 1 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 17008 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Apr 3 2004 12:00AM |
| NTSB Notification Time | 850 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Dec 28 2004 12:45PM |
| User who most recently changed record | NTSB\JOHB |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-FAT-FSDO |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N7NB |
| NTSB Number | LAX04LA176 |
| 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 | Bell |
| Aircraft Model | 47G-4A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 7732 |
| Certified Max Gross Weight | 2950 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 1 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | 100 Hour |
| Date of Last Inspection | Apr 2 2004 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 9916.2 |
| ELT Installed | No |
| ELT Activated | No |
| ELT Aided Location of Event Site | No |
| ELT Type | -- |
| Aircraft Owner Name | Inland Crop Dusters Inc. |
| Aircraft Owner Street Address | 5001 Stearman Ave |
| Aircraft Owner City | Shafter |
| Aircraft Owner State | CA |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 93263 |
| 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 | PWWG |
| Owner has at least one certificate | -- |
| Other Operator of large aircraft? | -- |
| 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 | No |
| Departure Airport Code | KMIT |
| Departure City | Shafter |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 700 |
| Departure Time Zone | PST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | -- |
| Destination State | -- |
| Destination Country | -- |
| Specific Phase of Flight | Maneuvering - aerial application |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Nov 6 2004 12:57PM |
| User who most recently changed record | COOS |
| Since inspection or accident | Last Inspection |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |