# NTSB CEN20LA125: Mitsubishi MU 2B-40, N425GZ, Chilton, WI, January 29, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: January 29, 2020, 09:00 local (15:00 UTC) - Place: Chilton, WI - Coordinates: 44.061111, -88.194999 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.0611&lon=-88.1950&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Honeywell Aerospace, Hartzell Propeller Inc, Flight Standards District Office, Mitsubishi Heavy Industries America, Inc. - NTSB case key (mKey): 101087 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA125 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101087/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101087 - Page: https://openairdocs.org/ntsb/CEN20LA125 ## Probable cause The pilot's decision to land on the turf runway with insufficient landing performance and his subsequent loss of control during the landing roll. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Mitsubishi MU-2B-40, 2 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=5780440), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Runway/land/takeoff/taxi surface](https://openairdocs.org/ntsb-findings/03023000): Environmental issues › Physical environment · Decision related to condition (probable cause); cases with it: [Mitsubishi MU-2B-40, 1 case](https://openairdocs.org/ntsb-findings/03023000/cases.md?model=5780440), [All aircraft, 253 cases](https://openairdocs.org/ntsb-findings/03023000/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mitsubishi MU-2B-40, 2 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=5780440), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Aircraft capability: landing distance](https://openairdocs.org/ntsb-findings/01061030): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Mitsubishi MU-2B-40, 1 case](https://openairdocs.org/ntsb-findings/01061030/cases.md?model=5780440), [All aircraft, 68 cases](https://openairdocs.org/ntsb-findings/01061030/cases.md) - [Performance/control parameters](https://openairdocs.org/ntsb-findings/01062000): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Mitsubishi MU-2B-40, 1 case](https://openairdocs.org/ntsb-findings/01062000/cases.md?model=5780440), [All aircraft, 1,269 cases](https://openairdocs.org/ntsb-findings/01062000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Mitsubishi MU-2B-40, 1 case](https://openairdocs.org/ntsb-events/230/sequence.md?model=5780440), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing: Dragged wing/rotor/float/other](https://openairdocs.org/ntsb-events/093); cases with it: [Mitsubishi MU-2B-40, 1 case](https://openairdocs.org/ntsb-events/093/sequence.md?model=5780440), [All aircraft, 319 cases](https://openairdocs.org/ntsb-events/093/sequence.md) ## Analysis The pilot was landing the turbine-powered airplane on a 2,500-ft-long frozen, turf runway. The pilot reported to the manufacturer that, during the landing roll, the airplane yawed left and the right wing contacted the ground, resulting in substantial damage. Examination of the airplane did not reveal any anomalies that would have resulted in a directional control issue. According to the pilot operating handbook, the airplane’s landing distance over a 50-ft for a dry, hard surface runway was about 2,500 ft. The manufacturer estimated that this distance for a wet or turf runway were about 4,250 ft. The pilot did not respond to requests for information regarding his flight planning or estimated landing distance. The pilot's decision to land on a runway that provided an inadequate distance likely resulted in an inability to maintain control of the airplane during the landing roll. ## Factual narrative The flight manual contained landing distance information for a dry, hard surface runway. Landing distance information for a turf runway was not available to the pilot. Investigators calculated airplane landing performance based on ambient temperature, calm wind, zero runway slope, an airplane weight of 500 lbs above empty weight, flaps at 20°, and no use of reverse thrust. Estimated landing distance over a 50 ft obstacle and ground roll were 2,500 and 1,500 ft, respectively. The airplane manufacturer estimated the landing distance over a 50 ft obstacle and ground roll for a turf (or wet) runway to be about 4,250 and 3,250 ft, respectively. The pilot did not respond to requests for additional information, such as expected landing distance, runway braking condition, touchdown location, actions taken after touchdown, and where the airplane departed the runway surface. According to the pilot, the turf runway was 2,500 ft x 85 ft; publicly available information indicated the turf runway was 1,000 x 60 ft. On January 29, 2020, about 0900 central standard time, a Mitsubishi MU-2B-40 airplane, N425GZ, was substantially damaged when it was involved in an accident at Flying Feathers Airport (11Y), Chilton, Wisconsin. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The National Transportation Safety Board (NTSB) was informed of the accident on March 12, 2020, by the airframe manufacturer; it was not reported to the NTSB by the pilot. The pilot stated that while landing at his private turf airstrip, the airplane yawed left and the right wing was substantially damaged when it contacted the ground. On December 14, 2019, the pilot completed an initial MU-2 training course, which included 14.9 flight hours and 20 hours of ground training as required 14 CFR Part 91 Subpart N. An examination of the airplane, which included engine rigging, propellers, and flight control continuity, did not reveal an anomaly that would have resulted in a directional control issue. ## Aircraft - Registration: [N425GZ](https://openairdocs.org/deregistered/N425GZ-2020-06-02), registration cancelled 2020-06-02, S/N 425 S.A., built 1980 (OpenAirDocs) - Reported make and model: Mitsubishi MU 2B-40 - Registry model: [Mitsubishi MU-2B-40](https://openairdocs.org/model/mitsubishi-mu-2b-40) (registry code 5780440) (OpenAirDocs) - Registry engine: [AiResearch TPE331 series](https://openairdocs.org/engine/airesearch-tpe331-series) (registry code 01514, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 425 S.A. - Year built: 1980 - Airframe hours: 4723 - Engines: Honeywell TPE-33110511M 940 horsepower turbo prop; Honeywell TPE-33110511M 940 horsepower turbo prop - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 9, 2019, 49 hours before - Departed: 8D1, New Holstein, WI - Destination: 11Y, Chilton, WI - Airport: 11Y, Flying Feathers, runway 18, 2,500 × 85 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review December 14, 2019; seat: left; restraint: 4-point; flight hours: 21,000 total, 93 in this make and model, 53 in the last 90 days, 27 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 2,800 ft overcast - Temperature: 25 °F, dew point 18 °F - Altimeter: 30.20 inHg - Observed at: KOSH, 16 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 20200129000939A](https://openairdocs.org/incident/20200129000939A), Jan 29, 2020: Mitsubishi MU-2B-40, Chilton, WI, Substantial damage. Aircraft landed and pilot claims had uncommanded yaw to the left. This caused the right wing tip to drop and make contact with the ground causing damage to the… ## Docket (7 files) The files NTSB released with the investigation on November 19, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101087. 6.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10124001&FileExtension=pdf&FileName=6120%20--_Redacted-Rel.pdf - Airport information (item 2, PDF, 3 pages, 343 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10124460&FileExtension=pdf&FileName=Airport%20Information-Rel.pdf - Landing performance information (item 3, PDF, 1 page, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10124469&FileExtension=pdf&FileName=Landing%20Distance%20Information-Rel.pdf - Weather information (item 4, PDF, 1 page, 38 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10124019&FileExtension=pdf&FileName=Weather%20Information-Rel.pdf - Initial FAA examination of airplane (item 5, PDF, 1 page, 39 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11355285&FileExtension=pdf&FileName=Record%20of%20Initial%20Examination%20by%20FAA-Rel.pdf - Examination of propellers (item 6, PDF, 11 pages, 992 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10124384&FileExtension=pdf&FileName=Examination%20-%20Propellers-Rel.pdf - Statement of party representatives to NTSB investigation (item 7, PDF, 3 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11347292&FileExtension=pdf&FileName=Party%20form%20final%20-%20redacted-Rel.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.