Rockwell International S-2R accident near Brawley, California, June 23, 2011
On June 23, 2011 at about 2:00 pm local time, a Rockwell International S-2R, registered N8520V, was substantially damaged in an accident during enroute (cruise) near Brawley, California (Brawley airport). It was an aerial application (crop spraying) flight under agricultural flying rules (Part 137). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The partial loss of engine power shortly after takeoff, which likely resulted from the failure of the piston connecting rod in cylinder number 3 due to hydraulic lock in that cylinder.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 23, 2011 · about 2:00 pm local time
- Place
- Brawley, California · Brawley · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Rockwell International S-2R · all S-2Rs on the register
- Registration
- N8520V · no longer on the register · serial 2280R
- 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 was en route to perform an aerial application pass when the airplane’s engine lost partial power. He made a forced landing in a nearby pasture; however, the airplane struck a railroad track during the landing roll, and a postcrash fire ensued. Examination of the radial engine revealed that the connecting rods for the pistons in cylinders 3 and 8 had failed, resulting in significant internal engine damage and the partial loss of power. Examination of the remains of the connecting rods for both cylinders revealed wear signatures that were mostly consistent with engine operation after failure. Because the engine continued operating after the failure, most features on the connecting rods fracture surfaces were obliterated, which made it difficult to identify the initial failure. However, further examination of the inside diameter surfaces of the wrist pin bearing of the number 3 cylinder connecting rod revealed wear signatures consistent with normal engine operation. Based on this finding, it is most likely that the event was initiated by the failure of the number 3 piston rod because it was not affected by the continued operation of the engine. The design of the engine's fuel priming system was such that cylinder number 3 was prone to piston hydraulic lock due to its low position within the priming system. Hydraulic lock is caused by excessive fuel being injected into a cylinder prior to engine start, and can be caused by either excessive priming, or a failure in the plunger or check valve assemblies, either of which could result in fuel trickling from the lowest nozzle within the system during non-operation. Postaccident fire damage precluded a thorough examination of the plunger and check valve assemblies. Hydraulic lock can result in a bent connecting rod and subsequent rod failure. The airplane was a low wing type, with integral wing fuel tanks located below the engine, and as such, it is unlikely that fuel had leaked into cylinder number 3 during non-operation.
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 enroute (cruise) defining event
- Off-field or emergency landing during landing (landing roll)
- Collision with terrain or object (not controlled flight into terrain) during landing (landing roll)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (reciprocating) › Recip eng cyl section › Failure
- cause Aircraft › Aircraft power plant › Engine fuel and control › (general) › Design
Pilot
- Certificate: commercial pilot
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: glider
- Flight time: 20,500 hours in all; 2,000 in this make and model; 150 in the last 90 days; 40 in the last 30 days; 20,000 as pilot in command
- Last flight review: November 1, 2009
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: serious injuries
The aircraft
- Airframe total time: 6,428 hours
- Last inspection: annual inspection, June 11, 2011; 21 hours since
- Maximum gross weight: 6,900 lb
- Seats: 1
- Landing gear: fixed
- Engine: Pratt And Whitney R1340 SERIES (piston); 0 hours total
- Fire on the ground
- Operator: Farm Aviation INC
The flight
- Departed from: BWC Brawley CA at 1:30 pm
- Destination: BWC Brawley CA
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 140° at 5 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 79°F (26°C), dew point 63°F (17°C)
- Altimeter: 29.71 inHg
- Observation at 1:53 pm from KIPL, 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 N8520V 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.