# NTSB CEN13LA426: Air Tractor AT-502, N502MH, Shannon, IL, July 20, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 20, 2013, 09:45 local (14:45 UTC) - Place: Shannon, IL - Coordinates: 42.181388, -89.67694 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.1814&lon=-89.6769&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 2, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - DuPage FSDO - NTSB case key (mKey): 87531 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN13LA426 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87531/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87531 - Page: https://openairdocs.org/ntsb/CEN13LA426 ## Probable cause The pilot’s inability to maintain an adequate climb rate after encountering a sudden wind shift during takeoff. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Wind: sudden wind shift](https://openairdocs.org/ntsb-findings/03034010): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-findings/03034010/cases.md?model=0390303), [All aircraft, 114 cases](https://openairdocs.org/ntsb-findings/03034010/cases.md) - [Aircraft capability: climb capability](https://openairdocs.org/ntsb-findings/01061010): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Air Tractor AT-502, 2 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md?model=0390303), [All aircraft, 183 cases](https://openairdocs.org/ntsb-findings/01061010/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Air Tractor AT-502, 8 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=0390303), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Air Tractor AT-502, 4 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=0390303), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Takeoff: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [Air Tractor AT-502, 5 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=0390303), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported that he had completed three uneventful aerial application flights on the day of the accident; however, shortly after lifting off for the fourth flight, the airplane encountered a sudden wind shear and was unable to climb out of ground effect. The airplane descended from an altitude of 10-12 feet above the ground into the corn crop located off the end of runway. The pilot reported no preaccident mechanical malfunctions or failures that would have precluded normal operation. A review of available wind data indicated that calm wind conditions prevailed throughout the morning; however, a shift to a northwest wind occurred about the time of the accident, which would have resulted in a tailwind and a reduced climb gradient. ## Factual narrative On July 20, 2013, at 0945 central daylight time, an Air Tractor model AT-502 airplane, N502MH, was substantially damaged when it impacted terrain shortly after takeoff at Sneek Airport (2IL0), Shannon, Illinois. The airline transport pilot was not injured. The airplane was registered to TW Air LLC and operated by Woodley Aerial Spray Inc., under the provisions of 14 Code of Federal Regulations Part 137, without a flight plan. Day visual meteorological conditions prevailed for the local aerial application flight that was departing at the time of the accident. The pilot reported that he had flown three uneventful aerial application flights earlier that morning in the accident airplane. After lifting off on the accident flight, the airplane encountered a sudden gust and was unable to maintain a climb outside of ground effect. The airplane descended from an altitude of 10-12 feet above the ground into the corn crop located off the end of runway 18 (2,640 feet by 125 feet, turf). The right main landing gear collapsed during the landing. The airplane came to rest upright and the pilot extracted himself from the airplane uninjured. The aft fuselage and wings were substantially damaged during accident impact sequence. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The nearest aviation weather reporting station was located at Albertus Airport (KFEP), Freeport, Illinois, about 6.5 miles northeast of the accident site. At 0935, the KFEP automated surface observing system reported the following weather conditions: wind 320 degrees true at 3 knots, visibility 10 miles, sky clear, temperature 26 degrees Celsius, dew point 19 degrees Celsius, altimeter setting 29.95 inches of mercury. A postaccident meteorological review of available wind data indicated that calm wind conditions prevailed throughout the morning; however, at 0935, the wind was from the northwest at 3 knots. ## Aircraft - Registration: [N502MH](https://openairdocs.org/aircraft/N502MH), registered now, S/N 502-0164, built 1992 (OpenAirDocs) - Reported make and model: Air Tractor Inc. AT-502 - Registry model: [Air Tractor AT-502](https://openairdocs.org/model/air-tractor-at-502) (registry code 0390303) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PT6A-60A](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-60a) (registry code 52043, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 502-0164 - Airframe hours: 8075 - Engines: Pratt & Whitney Canada PT6A-34AG 750 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Woodley Aerial Spray Inc. - Registered owner: TW Air LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 10, 2013 - Departed: 2IL0, Shannon, IL - Destination: 2IL0, Shannon, IL - Airport: 2IL0, Sneek Airport, runway 18, 2,640 × 125 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review May 8, 2013; seat: single; flight hours: 14,979 total, 320 in this make and model, 14,959 as pilot in command, 160 in the last 90 days, 40 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 66 °F - Altimeter: 29.95 inHg - Observed at: KFEP, 6 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 20130720013519A](https://openairdocs.org/incident/20130720013519A), Jul 20, 2013: Air Tractor Inc AT-502, Shannon, IL, Substantial damage. Pilot stated that this was his fourth flight of the day. He loaded 330 gallons of product and 80 gallons of fuel (544 pounds). Max gross for the plane is 8000… ## Docket (2 files) The files NTSB released with the investigation on August 5, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87531. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 954 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397702&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Information (item 2, .PDF, 99 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397703&FileExtension=.PDF&FileName=Weather%20Information-Master.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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.