Bell 47G5 accident near King City, California, September 11, 2013
On September 11, 2013 at about 2:15 pm local time, a 1967 Bell 47G5 (helicopter), registered N7836S, was substantially damaged in an accident during landing near King City, California (Mesa Del Rey Airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the helicopter’s center frame tube due to a fatigue crack and corrosion originating from a welded surface. Contributing to the accident was maintenance personnel’s inadequate inspection of the helicopter during its most recent 100-hour inspection.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- September 11, 2013 · about 2:15 pm local time
- Place
- King City, California · Mesa Del Rey Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 47G5, built 1967 · all 47G5s on the register
- Registration
- N7836S · registry record · serial 7860
- 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 flying low over a field when he heard a "loud bang." He initiated a precautionary landing, during which, the helicopter started to spin. The pilot lowered the collective, and the helicopter subsequently landed hard on a road. Postaccident examination of the helicopter structure revealed that one of the center frame tubes, located just aft of the cabin, had separated due to a fracture. Examination of the fracture surface revealed that a fatigue fracture initiated in the tube at the root of a fillet weld associated with a reinforcing fillet welded axially along the tube. The fatigue crack propagated through the thickness of the tube and circumferentially around the tube from both sides of the weld root. Darker corrosion product found on the fracture face indicated that the preexisting fatigue crack had been exposed to atmospheric elements. The tube fracture occurred in single-sided bending consistent with in-flight airframe loads. The helicopter's most recent 100-hour inspection occurred about 1 month before the accident. According to manufacturer's guidance, the 100-hour inspection required, in part, an inspection of all structural tubing and fittings for cracks, cuts, bends, corrosion, distortion, and damage. If maintenance personnel had adequately inspected this area, they might have identified the degradation of the tube.
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 structural failure during maneuvering (low-alt flying)
- Off-field or emergency landing during maneuvering (low-alt flying)
- Hard landing during landing defining event
The NTSB's findings
- cause Aircraft › Aircraft structures › Fuselage › Frames (main fuselage) › Fatigue/wear/corrosion
- cause Aircraft › Aircraft handling/service › Maintenance/inspections › Scheduled maint checks › Inadequate inspection
- cause Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instrument: airplane; rotorcraft: helicopter
- Flight time: 30,000 hours in all; 20,000 in this make and model
- Last flight review: April 6, 2012
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 16,798 hours
- Last inspection: continuous airworthiness programme, September 5, 2013; 10 hours since
- Maximum gross weight: 2,850 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming VO-435 SERIES (piston); 7,567 hours total
- Operator: Wilbur-Ellis CO
The flight
- Departed from: KIC King City CA
- Destination: KIC King City CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 320° at 4 knots
- Visibility: 10 statute miles
- Sky: overcast at 1,700 ft; clear
- Temperature: 63°F (17°C), dew point 55°F (13°C)
- Altimeter: 30.00 inHg
- Observation at 2:53 pm from SNS, 40 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.
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.