# NTSB CEN12LA459: Air Tractor AT-502B, N205SK, Wisner, LA, July 18, 2012

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Limited investigation · Final report
- Date: July 18, 2012, 11:00 local (16:00 UTC)
- Place: Wisner, LA
- Coordinates: 31.946111, -91.562774 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.9461&lon=-91.5628&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Defining event: [Initial climb: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report October 9, 2012
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA -- Baton Rouge Flight Standards
- NTSB case key (mKey): 84387
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA459
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84387/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84387
- Page: https://openairdocs.org/ntsb/CEN12LA459

## Probable cause

The pilot’s inadequate takeoff planning that did not consider the reduced acceleration due to a rough, turf runway and his use of an improper flap setting, which resulted in a collision with terrain during takeoff.

## Findings

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

- [Airport facilities/design: runway/landing area condition](https://openairdocs.org/ntsb-findings/03017035): Environmental issues › Operating environment · Effect on operation; cases with it: [Air Tractor AT-502B, 2 cases](https://openairdocs.org/ntsb-findings/03017035/cases.md?model=0390307), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/03017035/cases.md)
- [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Air Tractor AT-502B, 4 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=0390307), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md)
- [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Air Tractor AT-502B, 4 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=0390307), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md)
- [Wing structure: trailing edge flaps](https://openairdocs.org/ntsb-findings/01035753): Aircraft › Aircraft structures · Incorrect use/operation (probable cause); cases with it: [Air Tractor AT-502B, 2 cases](https://openairdocs.org/ntsb-findings/01035753/cases.md?model=0390307), [All aircraft, 33 cases](https://openairdocs.org/ntsb-findings/01035753/cases.md)
- [Planning/preparation: performance calculations](https://openairdocs.org/ntsb-findings/02061010): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Air Tractor AT-502B, 3 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md?model=0390307), [All aircraft, 114 cases](https://openairdocs.org/ntsb-findings/02061010/cases.md)

## Sequence of events

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

- [Initial climb: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Air Tractor AT-502B, 8 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=0390307), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md)

## Analysis

The pilot reported that the airplane lifted off of the 2,500-foot long, rough, turf airstrip about 100 feet before the end of the runway. However, the airplane did not climb out of ground effect, and it settled into a bean field. He stated that there were no mechanical issues with the airplane during the accident takeoff. The pilot had reduced the chemical load for the agricultural application flight due to the runway length and ambient temperature, and he had elected to conduct the accident takeoff with the wing flaps extended to about 25 degrees. He reported a gross weight for the accident takeoff of 10,100 lbs. Performance data indicated that a takeoff distance of about 2,600 feet was required to clear a 50-foot obstacle. However, that data was applicable to a hard surface runway at a maximum certificated gross takeoff weight of 8,000 lbs with 10 degrees of flaps. The airplane flight manual did not contain takeoff data for weights or flap settings in excess of 8,000 lbs and 10 degrees, respectively. The airplane manufacturer recommended that takeoffs not be attempted with more than 10 degrees of flap. Regulations and guidance related to agricultural application flights in restricted category airplanes allowed for operations up to 31 percent above the certificated gross takeoff weight. The pilot reported that the maximum gross weight for the airplane was 10,480 lbs, which corresponded to the 31 percent limit. FAA guidance suggested that an increase in takeoff gross weight of 31 percent will increase the required takeoff distance by about 90 percent. The reduced acceleration due to the rough, turf runway and the excess flap deflection selected by the pilot, combined with operating near the maximum permitted takeoff gross weight, resulted in the airplane's inability to attain a positive rate of climb after liftoff.

## Factual narrative

On July 18, 2012, about 1100 central daylight time, an Air Tractor AT-502B, N205SK, impacted a bean field after takeoff from a private airstrip near Wisner, Louisiana. The pilot sustained a serious injury. The airplane was substantially damaged. The airplane was registered to and operated by Delta Dusters LLC under the provisions of 14 Code of Federal Regulations Part 137 as an agricultural application flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight was originating at the time of the accident. The pilot reported that the airplane lifted off of the 2,500-foot long turf airstrip about 100 feet before the end of the runway. However, the airplane did not climb out of ground effect and it settled into a bean field located off the end of the runway, substantially damaging both wings. He noted that the engine seemed to be "making good power" and there did not seem to be any mechanical issues during the accident takeoff. The pilot commented that the runway was rough and "needed the grass cut." He reduced the chemical load to 375 gallons due to the runway length and ambient temperature. In addition, the pilot stated that he extended the wing flaps to about three-quarters of full deflection for takeoff. The wind was from the south at about 3 knots. The accident takeoff was to the east. A postaccident examination conducted by a Federal Aviation Administration (FAA) inspector did not reveal any anomalies consistent with a preimpact failure or malfunction. At the time of the examination, the wing flap actuator extension corresponded to a full down (25 degrees) deflection. The airplane flight manual stated that takeoffs with a full chemical hopper load from a short field should be made with a 10-degree flap deflection. The manual also noted that the takeoff roll and acceleration will be adversely affected by grassy or soft runway surfaces. The flight manual did not authorize takeoffs with flaps extended in excess of 10 degrees. The pilot reported an operating weight at the time of the accident of 10,100 lbs., with a maximum gross weight of 10,480 lbs. The airplane manufacturer's documentation specified a maximum certificated takeoff weight of 8,000 lbs. Regulations and FAA guidance allow agricultural operators of restricted category airplanes to operate at weights in excess of the maximum certificated weights. In accordance with Civil Aeronautics Manual (CAM) 8 and Advisory Circular 20-33B, the airplane manufacturer demonstrated operations at 9,400 lbs. However, the guidance allowed operations of the AT-502B at weights up to 31-percent above the certificated takeoff weight (10,480 lbs.) provided that the operator performed a flight check confirming safe flight characteristics at that weight. The airplane flight manual noted a takeoff distance required to clear a 50-foot obstacle of about 2,600 feet. This distance was applicable to departure from a hard surface runway, at a gross weight of8,000 lbs. with 10 degrees flaps, at a pressure altitude of 0 feet (sea level), and an ambient temperature of 30 degrees Celsius. The flight manual did not contain takeoff data for weights or flap settings in excess of 8,000 lbs. and 10 degrees, respectively. The airplane manufacturer did not recommend that takeoffs be attempted with more than 10 degrees of flap. Federal Aviation Administration guidance contained in the Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25A) stated that a 10-percent increase in gross weight will result in at least a 21-percent increase in the takeoff distance required. In addition, the handbook noted that operations on any surface that is not hard and smooth will increase the ground roll during takeoff. The handbook also noted that it is possible to fly an airplane just clear of the ground at a slightly slower airspeed than that required to sustain level flight at higher altitudes due to a phenomenon known as ground effect. An airplane leaving ground effect after takeoff will experience an increase in drag and thrust required to maintain flight.

## Aircraft

- Registration: [N205SK](https://openairdocs.org/deregistered/N205SK-2024-06-20), registration cancelled 2024-06-20, S/N 502B-0628, built 2001 (OpenAirDocs)
- Reported make and model: AIR TRACTOR INC AT-502B
- Registry model: [Air Tractor AT-502B](https://openairdocs.org/model/air-tractor-at-502b) (registry code 0390307) (OpenAirDocs)
- Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 502B-0628
- Airframe hours: 6658
- Engines: P&W PT6A SERIES 500 horsepower turbo prop
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Delta Dusters LLC
- Registered owner: Delta Dusters LLC
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, July 2, 2012
- Departed: PVT, Wisner, LA
- Destination: PVT, Wisner, LA
- Airport: PVT, Private, runway 09, 2,300 × 75 ft, grass/turf

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 67; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review December 17, 2011; seat: front; flight hours: 23,000 total, 3,000 in this make and model, 300 in the last 90 days, 150 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 86 °F, dew point 72 °F
- Altimeter: 30.06 inHg
- Observed at: HEZ, 22 nm away

## 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 20120718016659A](https://openairdocs.org/incident/20120718016659A), Jul 18, 2012: Air Tractor Inc AT-502B, Sicily Island, LA, Substantial damage. Aircraft loaded with 375 gallons of ag chemical. Take off attempted on a grass airstrip. Aircraft got into ground effect appx 5 to 7 feet off the ground.…

## Other investigations on N205SK (2)

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.

- [NTSB CEN22LA310](https://openairdocs.org/ntsb/CEN22LA310), Jul 10, 2022: Air Tractor AT-502B (N205SK), Wyoming, IL, substantial damage. Probable cause: The pilot’s improper landing flare, which resulted in a hard, bounced landing.
- [NTSB GAA18CA476](https://openairdocs.org/ntsb/GAA18CA476), Jul 30, 2018: Air Tractor AT502 (N205SK), Louise, MS, substantial damage. Probable cause: The pilot's improper landing flare, which resulted in a hard, bounced landing and a subsequent loss of directional control.

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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