Bell 47G-4A accident near Shafter, California, January 22, 2010
On January 22, 2010 at about 5:09 pm local time, a Bell 47G-4A (helicopter), registered N28938, was substantially damaged in an accident during landing (flare/touchdown) near Shafter, California. It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The loss of a main rotor blade counterweight due to corrosion. Contributing to the accident was the failure of the operator to perform the initial and recurrent inspections required by a Service Bulletin to detect the corrosion in the counterweight.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- January 22, 2010 · about 5:09 pm local time
- Place
- Shafter, California · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G-4A · all 47G-4As on the register
- Registration
- N28938 · no longer on the register · serial 7728
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that he was maneuvering the helicopter to make an aerial application pass. At approximately 80 feet above ground level, he heard a muffled "crack/bang" and the helicopter immediately yawed and he experienced lateral vibrations in the cyclic. The pilot then initiated a forced landing with the shaking becoming more violent. The helicopter subsequently landed hard with the engine still running. The main rotor blades contacted and severed the tail boom, and the engine separated from its mounts. Postaccident examination of the helicopter revealed that a main rotor counterweight was missing. Examination of the broken counterweight rod end showed evidence of corrosion over approximately 45 percent of the diameter of the rod end. Maintenance records indicate that a Service Bulletin to inspect main rotor counterweight rods for pit corrosion had not been complied with. The Service Bulletin states that after an initial inspection of the main rotor counterweight rods, recurrent inspections should be accomplished every 300 hours of time in service.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft maintenance event during prior to flight
- Part(s) separation from AC during maneuvering
- Hard landing during landing (flare/touchdown) defining event
The NTSB's findings
- cause Aircraft › Aircraft systems › Flight control system › (general) › Failure
- factor Personnel issues › Task performance › Inspection › (general) › Maintenance personnel
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 32,000 hours in all; 4,000 in this make and model; 31,280 as pilot in command
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 7,207 hours
- Last inspection: continuous airworthiness programme
- Seats: 3
- Landing gear: fixed
- Engine: Lycoming VO-540 SERIES (piston); 0 hours total
- Operator: Inland Crop Dusters INC
The flight
- Departed from: MIT Shafter CA at 4:50 pm
- Destination: MIT Shafter CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 090° at 7 knots
- Visibility: 10 statute miles
- Sky: broken clouds at 4,400 ft; a few clouds at 3,500 ft
- Temperature: 46°F (8°C), dew point 39°F (4°C)
- Altimeter: 29.45 inHg
- Observation at 4:54 pm from BFL, 10 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N28938 the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.