# NTSB CEN11LA571: Air Tractor AT-402, N10119, Uvalde, TX, August 13, 2011

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 13, 2011, 10:30 local (15:30 UTC)
- Place: Uvalde, TX
- Coordinates: 29.206666, -99.614997 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.2067&lon=-99.6150&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report January 17, 2012
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA Flight Standards District Office
- NTSB case key (mKey): 81488
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA571
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81488/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81488
- Page: https://openairdocs.org/ntsb/CEN11LA571

## Probable cause

The pilot’s failure to maintain airspeed while maneuvering to avoid power lines during a precautionary landing, which resulted an aerodynamic stall. Contributing to the accident was the fluctuating engine power for undetermined reasons and the pilot's preoccupation with the malfunctioning global positioning system.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Air Tractor AT-402, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=0390205), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md)
- [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Air Tractor AT-402, 3 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=0390205), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md)
- [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Air Tractor AT-402, 3 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=0390205), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md)
- [Attention/monitoring: task monitoring/vigilance](https://openairdocs.org/ntsb-findings/02021520): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md?model=0390205), [All aircraft, 330 cases](https://openairdocs.org/ntsb-findings/02021520/cases.md)
- [Aircraft](https://openairdocs.org/ntsb-findings/01050000): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-findings/01050000/cases.md?model=0390205), [All aircraft, 151 cases](https://openairdocs.org/ntsb-findings/01050000/cases.md)
- [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined; cases with it: [Air Tractor AT-402, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=0390205), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md)
- [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=0390205), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Air Tractor AT-402, 2 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=0390205), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md)
- [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Air Tractor AT-402, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390205), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)
- [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Air Tractor AT-402, 6 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390205), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot said he had just completed spraying a field during the aerial application flight when he noted that the airplane's global positioning system (GPS) unit had malfunctioned. As he attempted to troubleshoot the problem, the airplane’s engine power began to fluctuate. The pilot decided to make a precautionary landing. He looked inside the cockpit at the GPS, and, when he looked back outside, he noticed a set of power lines crossing the road. He was able to avoid them, then saw a second set of power lines. As he maneuvered the airplane to avoid them, he inadvertently stalled the airplane. The airplane’s right wing dropped and struck the power lines. The airplane then spun around and impacted terrain in an inverted attitude. A postaccident examination could not determine the reason for the drop in engine power. No other anomalies with the airplane were found.

## Factual narrative

On August 13, 2011, approximately 1030 central daylight time, an Air Tractor AT-402, N10119, collided with a power lines and impacted an open field during a precautionary landing near Uvalde, Texas. The commercial pilot was not injured. The airplane sustained substantial damage to the right wing, vertical stabilizer, and rudder. The airplane was registered to and operated by L&W Flying Service under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from Garner Field (UVA), Uvalde, approximately 0940. The pilot said that after spraying a field, the airplane's Global Positioning System (GPS) unit malfunctioned. As he attempted to troubleshoot the problem, he noticed that engine torque dropped momentarily, then returned to 1200 pounds. Shortly thereafter, engine torque dropped again and the pilot decided to make a precautionary landing on a road. While on final approach to the road, the pilot looked inside the cockpit momentarily and when he looked outside, he noticed a set of power lines crossing the road. He was able to avoid them. The pilot then saw a second set of power lines, and while maneuvering to avoid them, inadvertently stalled the airplane. The right wing dropped, striking the power lines. The airplane spun around and impacted terrain in an inverted attitude. A postaccident examination of the engine and other airplane systems showed no anomalies. The reason for the drop in engine torque was not determined.

## Aircraft

- Registration: [N10119](https://openairdocs.org/deregistered/N10119-2018-01-09), registration cancelled 2018-01-09, S/N 402-0711, built 1989 (OpenAirDocs)
- Reported make and model: AIR TRACTOR INC AT-402
- Registry model: [Air Tractor AT-402](https://openairdocs.org/model/air-tractor-at-402) (registry code 0390205) (OpenAirDocs)
- Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 402-0711
- Airframe hours: 11000
- Engines: P&W PT6A-15AG 680 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: L & W Flying Service, Inc.
- Registered owner: L & W Flying Service, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 3, 2011
- Departed: KUVA, Uvalde, TX
- Destination: KUVA, Uvalde, TX
- Flight plan: Unknown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 18, 2011; seat: center; flight hours: 3,700 total, 1,800 in this make and model, 3,500 as pilot in command, 290 in the last 90 days, 102 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 95 °F, dew point 64 °F
- Altimeter: 29.95 inHg
- Observed at: KUVA

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20110813022059A](https://openairdocs.org/incident/20110813022059A), Aug 13, 2011: Air Tractor Inc AT-402, Uvalde, TX, Destroyed. On August 13, 2011, an Air-tractor model at 402, single engine airplane crashed landed north on hwy 117 near Uvalde, TX. PIC reported of conducing part 137…

## Docket (2 files)

The files NTSB released with the investigation on December 8, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81488. 460 KB in all.

- NTSB Form 6120, Pilot-Operator Aircraft Accident Report (item 1, .PDF, 449 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355248&FileExtension=.PDF&FileName=NTSB%20Form%206120,%20Pilot-Operator%20Aircraft%20Accident%20Report-Redacted.PDF
- FAA Inspector's Statement (item 2, .PDF, 11 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40355713&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Statement-Redacted.PDF

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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