Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Porterville, California 93267
Sunday, July 20, 2003 1:30 PDT
NTSB Narrative Summary Released at Completion of Accident
During an agricultural spray flight, when the helicopter's drive system disconnected from the engine, the helicopter yawed and descended about 10 feet into the underlying cotton field. The helicopter rolled upon impacting the uneven terrain. Prior to the event, the pilot heard the transmission make a loud noise and the engine oversped. The helicopter's drive system was examined, and 12 bolts on the planetary gear flange were found broken due to fatigue.
NTSB Probable Cause Narrative
Fatigue-induced failure of bolts in the helicopter's rotor drive flange, which resulted in a total loss of torque to the rotor drive shaft.
Event Information
| Type of Event | Accident |
| Event Date | 7/20/2003 |
| Event Day of the Week | Sunday |
| Time of Event | 130 |
| Event Time Zone | Pacific Daylight Time |
| Event City | Porterville |
| Event State | CALIFORNIA |
| Event Country | -- |
| Zipcode of the event site | 93267 |
| Event Date Year | 2003 |
| Event Date Month | 7 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 360754N |
| Event Location Longitude | 1191254W |
| 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 | 315 Pacific Daylight Time |
| Direction of event from weather observation facility (degrees) | 90 |
| Weather Observation Facility ID | PVT |
| Elevation of weather observation facility | 442 |
| Distance of event from weather observation facility (units?) | 10 |
| Time Zone of the weather observation | PDT |
| Lighting Conditions | Night/Dark |
| 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) | 24 |
| Dew Point at event time (in degress fahrenheit) | 15 |
| Wind Direction (degrees magnetic) | 140 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 6 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 29.91 |
| 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) | 16558 |
| NTSB Notification Source | FAA |
| NTSB Notification Date | Jul 20 2003 12:00AM |
| NTSB Notification Time | 242 |
| Fiche Number and/or location -used to find docket information | DMS |
| Date of most recent change to record | Oct 28 2004 10:11AM |
| User who most recently changed record | NTSB\MONR |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | WP-FSDO Fresno, CA |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N4774S |
| NTSB Number | LAX03LA236 |
| 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-2A |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | WAV182 |
| Certified Max Gross Weight | 2850 |
| 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 | -- |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Annual |
| Date of Last Inspection | Jul 17 2002 12:00AM |
| Airframe hours since last inspection | 78 |
| Airframe Hours | 2800 |
| ELT Installed | No |
| ELT Activated | Unknown |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | Sky Tech Corp. of Minnesota, Inc. |
| Aircraft Owner Street Address | 42370 CO 14 Blvd. |
| Aircraft Owner City | Kenyon |
| Aircraft Owner State | MN |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 55946 |
| Operator is an individual? | No |
| Operator Name | JOHNS AERIAL SPRAYING |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | -- |
| Operator City | Bakersfield |
| Operator State | CA |
| Operator Country | USA |
| Operator Zip code | 93301 |
| Operator Code | YL7G |
| 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 | Yes |
| Departure Airport Code | -- |
| Departure City | Porterville |
| Departure State | CA |
| Departure Country | USA |
| Departure Time | 0 |
| Departure Time Zone | PDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | -- |
| Destination City | Porterville |
| Destination State | CA |
| Destination Country | USA |
| Specific Phase of Flight | Maneuvering - aerial application |
| Report sent to ICAO? | No |
| Evacuation occurred | No |
| Date of most recent change to record | Sep 22 2004 1:43PM |
| User who most recently changed record | JOHB |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | NA |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |