# NTSB CEN11CA565: Weatherly 201C, N9054W, Bronson, IA, August 10, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 10, 2011, 09:45 local (14:45 UTC) - Place: Bronson, IA - Coordinates: 42.39722, -96.223052 - Nearby events: https://openairdocs.org/map.md?lat=42.3972&lon=-96.2231&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 October 17, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Des Moines Flight Standards - NTSB case key (mKey): 81463 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11CA565 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81463/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81463 - Page: https://openairdocs.org/ntsb/CEN11CA565 ## Probable cause The pilot's failure to maintain clearance from terrain while maneuvering during an aerial application flight. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=9630410), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/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: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=9630410), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=9630410), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-findings/02021545/cases.md?model=9630410), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/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: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=9630410), [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: [Weatherly 201C, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=9630410), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the airplane’s airspeed decayed when he maneuvered to avoid some high tension power lines, while conducting an agricultural application pass. He leveled the wings and applied full engine power. The pilot turned further in an effort to avoid a populated area and toward a low point in the rising terrain. The airplane then entered a valley located between rolling hills, at which time the airplane started to sink. The airplane's right wing struck a tree and the airplane subsequently impacted the ground. The airplane sustained substantial damage to the right wing and fuselage. The pilot reported that there were no mechanical malfunctions or anomalies with the airplane. ## Factual narrative The pilot reported that the airplane’s airspeed decayed when he maneuvered to avoid some high tension power lines while conducting an agricultural application pass. He leveled the wings and applied full engine power. The pilot turned further in an effort to avoid a populated area and toward a low point in the rising terrain. The pilot added that after exiting the agricultural field, the airplane entered a valley located between rolling hills, at which time the airplane started to sink. There was a tree that was going to be a conflict so the pilot attempted to dump the chemical load. The airplane's right wing struck the tree and the airplane subsequently impacted the ground. The airplane sustained substantial damage to the right wing and fuselage. The pilot reported that there were no failures or malfunctions associated with the airplane prior to the accident. ## Aircraft - Registration: [N9054W](https://openairdocs.org/aircraft/N9054W), registered now, S/N 1022, built 1977 (OpenAirDocs) - Reported make and model: WEATHERLY 201C - Registry model: [Weatherly 201C](https://openairdocs.org/model/weatherly-201c) (registry code 9630410) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1022 - Airframe hours: 4837 - Engines: P&W R-985 SERIES 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Sioux Air Inc - Registered owner: Sioux Air Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 17, 2011 - Departed: 7K8, S Sioux City, NE - Destination: 7K8, S Sioux City, NE - Airport: 7K8, Martin Field ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 73; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review August 1, 2011; seat: single; flight hours: 30,300 total, 70 in this make and model, 29,250 as pilot in command, 102 in the last 90 days, 39 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 54 °F - Altimeter: 29.98 inHg - Observed at: SUX, 8 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 20110810017729A](https://openairdocs.org/incident/20110810017729A), Aug 10, 2011: Weatherly 201C, Bronson, IA, Substantial damage. The pilot was conducting aerial application operations with a full hopper of chemical. As the aircraft climbed to avoid power lines, the pilot reported the… ## Other investigations on N9054W (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 CHI97LA219](https://openairdocs.org/ntsb/CHI97LA219), Jul 18, 1997: Weatherly 201C (N9054W), Stephen, MN, substantial damage. Probable cause: the pilot's exceeding the design stress limits of the aircraft. A factor was the crosswind. - [NTSB CHI94LA320](https://openairdocs.org/ntsb/CHI94LA320), Sep 11, 1994: Weatherly 201C (N9054W), Stephen, MN, substantial damage. Probable cause: improper rigging of the parking brake control cable resulting in inadvertent application of the left wheel brake. ## Docket (2 files) The files NTSB released with the investigation on September 7, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81463. 832 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 815 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353437&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot Statement to FAA (item 2, .PDF, 17 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40353436&FileExtension=.PDF&FileName=Pilot%20Statement%20to%20FAA-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. --- 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.