Schweizer Aircraft CORP G-164B accident near Yuba City, California, July 9, 2011
On July 9, 2011 at about 9:30 pm local time, a Schweizer Aircraft CORP G-164B, registered N7503L, was substantially damaged in an accident during initial climb near Yuba City, California. 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).
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The NTSB's probable cause their words, unchanged
High-cycle fatigue on the 1st-stage compressor blade retaining ring, which resulted in the ring’s fracture and a subsequent loss of engine power.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 9, 2011 · about 9:30 pm local time
- Place
- Yuba City, California · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Schweizer Aircraft CORP G-164B · all G-164Bs on the register
- Registration
- N7503L · registry record · serial 826B
- 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, during the initial climb, he heard a "loud pop" and observed fire coming from both exhaust stacks before the engine lost power. He subsequently made an off-airport landing to an adjacent road. During the landing, the airplane slid into a ditch, the landing gear sheared off, and the airplane nosed over. A postaccident engine examination revealed that the blade retaining ring of the 1st-stage compressor blades had fractured into several pieces; about 30 percent of the ring was not recovered. A metallurgical examination of the recovered sections of the retaining ring revealed that all but two of the fractures were due to ductile overload. An examination of the nonoverload fractures revealed fatigue originating from the rivet hole areas, which was indicative of high-cycle fatigue. The power section had been overhauled 747 hours before the accident. According to the overhaul manual current at the time of the overhaul, the blade retaining ring was an on-condition inspection item and not required to be replaced at overhaul. The fatigue fracture of the 1st-stage compressor blade retaining ring likely affected the engine's ability to produce power.
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
- Loss of engine power (total) during initial climb defining event
- Off-field or emergency landing during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Compressor section › Fatigue/wear/corrosion
- Environmental issues › Physical environment › Terrain › Rough terrain › Effect on equipment
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; rotorcraft: helicopter
- Flight time: 11,433 hours in all; 5,533 in this make and model; 250 in the last 90 days; 200 in the last 30 days; 11,433 as pilot in command
- Last flight review: March 18, 2011
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: sngl
- Injury: no injuries
The aircraft
- Airframe total time: 10,282 hours
- Last inspection: annual inspection, April 19, 2011; 373 hours since
- Maximum gross weight: 5,200 lb
- Seats: 1
- Landing gear: fixed
- Engine: P&W PT6A-34 (turboprop); 8,503 hours total
- Operator: Onstott Dusters INC
The flight
- Departed from: Yuba City CA at 9:30 pm
- Destination: Yuba City CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 190° at 16 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 91°F (33°C), dew point 61°F (16°C)
- Altimeter: 29.75 inHg
- Observation at 9:53 pm from KMYV
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 |
Other NTSB records under N7503L the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR11LA320.