Ayres S2R600 accident near Pine Bluff, Arkansas, July 6, 2011
On July 6, 2011 at about 3:30 pm local time, a Ayres S2R600, registered N3101S, was substantially damaged in an accident during initial climb near Pine Bluff, Arkansas (Ladd Airstrip 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 use of an incorrect mounting bolt by maintenance persons to attach the engine torque sensor, which resulted in an internal failure of the torque sensor and subsequent loss of engine power due to fuel starvation.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 6, 2011 · about 3:30 pm local time
- Place
- Pine Bluff, Arkansas · Ladd Airstrip · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Ayres S2R600 G6
- Registration
- N3101S · registry record · serial G6-106
- Damage
- Substantial damage
- Flight
- Aerial application (crop spraying) flight · agricultural flying rules (Part 137)
The NTSB's narrative final · quoted from the NTSB record
After the airplane sustained a complete loss of engine power during initial climb, the pilot performed an off-airport landing. Postaccident examination revealed that three teeth in the torque sensor spur gear separated after four of the five torque sensor mounting bolts became loose. The loose bolts caused the torque sensor housing to move radially away from the gear case, causing the teeth to overload and separate. Subsequently, the engine’s fuel pump and fuel control were no longer driven by the gears in the gear train, which were normally driven by the torque sensor spur gear, thus the engine was starved of fuel. Metallurgical examination showed that the bolts became loose because a bolt that was undersized and of the incorrect configuration had been installed. A maintenance record showed that the engine had previously been disassembled due to a torque sensor failure and an overhauled torque sensor had been reinstalled.
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
- Powerplant sys/comp malf/fail during initial climb defining event
- Loss of engine power (total) during initial climb
- Off-field or emergency landing
- Collision with terrain or object (not controlled flight into terrain)
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Accessory drives › Malfunction
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Accessory drives › Incorrect service/maintenance
Pilot
- Certificate: airline transport pilot, flight instructor, flight engineer
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instrument: airplane
- Flight time: 35,000 hours in all; 250 in this make and model; 250 in the last 90 days; 150 in the last 30 days; 350 on instruments
- Last flight review: February 17, 2011
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: sngl
- Injury: minor injuries
The aircraft
- Airframe total time: 7,467 hours
- Last inspection: 100-hour inspection, June 21, 2011; 20 hours since
- Maximum gross weight: 6,000 lb
- Seats: 1
- Landing gear: fixed
- Engine: Garrett TPE331 (turboprop); 0 hours total
- Operator: Swan Lake Flying Service, Inc.
The flight
- Departed from: Pine Bluff AR at 3:30 pm
- Destination: Pine Bluff AR
- Flight plan: none
- Runway 09, 3,900 ft by 40 ft
Weather at the time
- Light: daylight
- Wind: at 4 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 88°F (31°C), dew point 70°F (21°C)
- Altimeter: 30.01 inHg
- Observation at 3:53 pm from KPBF, 3 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.