# NTSB CHI08CA257: Air Tractor AT-400A, N7307W, Luverne, MN, August 16, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 16, 2008, 10:00 local (15:00 UTC) - Place: Luverne, MN - Coordinates: 43.621665, -96.216667 - Nearby events: https://openairdocs.org/map.md?lat=43.6217&lon=-96.2167&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 26, 2008 - Report: Approved by Office Director - Parties: MSP FSDO - NTSB case key (mKey): 68875 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA257 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/68875/pdf - Page: https://openairdocs.org/ntsb/CHI08CA257 ## Probable cause The failure of the compressor turbine blades which resulted in the loss of power. Factors associated with the accident were the low altitude and the trees. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (turbine/turboprop): compressor section](https://openairdocs.org/ntsb-findings/01057230): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Air Tractor AT-400A, 1 case](https://openairdocs.org/ntsb-findings/01057230/cases.md?model=0390203), [All aircraft, 53 cases](https://openairdocs.org/ntsb-findings/01057230/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Air Tractor AT-400A, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=0390203), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/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: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Air Tractor AT-400A, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=0390203), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Air Tractor AT-400A, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=0390203), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-flare/touchdown: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Air Tractor AT-400A, 2 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=0390203), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The accident occurred during an aerial application flight. The pilot reported she had sprayed approximately 40 acres when the engine began making a "popping" sound with a higher pitched whistle. She reported she pulled back on the elevator control to gain as much altitude as possible and began looking for a place to land. She stated that while looking out the right side of the airplane, she noticed flames coming from the right side exhaust stack. The pilot determined she was not able to land on the country road, so she decided to try and fly between a couple of trees to land in an open field. She stated the airplane touched down prior to the trees and it spun to the right, impacting one of the trees with the left wing. Inspection of the engine revealed that all of the compressor turbine blades were damaged with most of them having broken off. Damage was also present to the outlet side of the compressor turbine guide vanes. ## Factual narrative On August 16, 2008, at 1000 central daylight time, an Air Tractor AT-400A, N7307W, operated by Wilbur-Ellis Air LLC, collided with a tree during an off airport forced landing in Luverne, Minnesota. The commercial pilot was not injured. The airplane sustained substantial damage to the left wing. The aerial application flight was operating under Title 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed and no flight plan was filed. The local flight originated from the Luverne Municipal Airport (LYV), Luverne, Minnesota, at 0950. The pilot reported she had sprayed approximately 40 acres when the engine began making a "popping" sound with a higher pitched whistle. She reported she pulled back on the elevator control to gain as much altitude as possible and began looking for a place to land. She stated that while looking out the right side of the airplane, she noticed flames coming from the right side exhaust stack. The pilot determined she was not able to land on the country road, so she decided to try and fly between a couple of trees to land in an open field. She stated the airplane touched down prior to the trees and it spun to the right, impacting one of the trees with the left wing. Inspection of the engine revealed that all of the compressor turbine blades were damaged with most of them having broken off. Damage was also present to the outlet side of the compressor turbine guide vanes. ## Aircraft - Registration: [N7307W](https://openairdocs.org/deregistered/N7307W-2012-10-10), registration cancelled 2012-10-10, S/N 400A-0613, built 1985 (OpenAirDocs) - Reported make and model: Air Tractor AT-400A - Registry model: [Air Tractor AT-400A](https://openairdocs.org/model/air-tractor-at-400a) (registry code 0390203) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 400A-613 - Engines: Pratt & Whitney Canada PT6A-20 turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Wilbur-Ellis Air LLC - Airworthiness certificate: Special, Restricted (Special) - Departed: LYV, Luverne, MN - Destination: LYV ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; flight hours: 3,656 total, 219 in this make and model, 3,167 as pilot in command, 344 in the last 90 days, 181 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 63 °F - Altimeter: 30.27 inHg - Observed at: FSD ## 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 20080816846649A](https://openairdocs.org/incident/20080816846649A), Aug 16, 2008: Airtrc AT400A, Luverne, MN, Destroyed. (-23) The engine CT blades failed causing the aircraft to lose power and crash into a very wet pasture and then hit a large tree. The pilot attempted to land… 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.