# NTSB CEN12CA641: Piper PA-11, N4589M, Ft. Morgan, CO, September 10, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: September 10, 2012, 13:00 local (19:00 UTC) - Place: Ft. Morgan, CO - Coordinates: 40.333889, -103.804168 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.3339&lon=-103.8042&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: 2 uninjured - Status: Completed, report January 22, 2013 - Report: Approved by Office Director - NTSB office: Central Region - NTSB case key (mKey): 85066 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12CA641 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/85066/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=85066 - Page: https://openairdocs.org/ntsb/CEN12CA641 ## Probable cause The pilot's loss of control during landing after encountering an unexpected wind gust. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-11, 6 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7101102), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Awareness of condition; cases with it: [Piper PA-11, 2 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=7101102), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Piper PA-11, 2 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=7101102), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-11, 5 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7101102), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis While practicing landings, the sport pilot performed a three-point, full-flap landing on the runway. During the landing roll, an unexpected wind gust knocked the tail wheel out of its detent and the pilot was unable to maintain directional control of the airplane. The airplane ground looped and sustained substantial damage to the right wing, right aileron, and fuselage. The pilot reported that there were no mechanical malfunctions with the airplane before the accident. The pilot and the flight instructor reported the wind was about 3 to 4 knots down the runway, with dust devils crossing the runway. ## Factual narrative While practicing landings, the sport pilot performed a three-point, full flap landing on the runway. During the landing roll, the airplane experienced an unexpected wind gust to the left side of the airplane. The wind gust knocked the tail wheel out of its detent and the pilot was unable to maintain directional control of the airplane. The airplane ground looped resulting in substantial damage to the right wing, right aileron, and fuselage. The pilot reported no mechanical malfunctions with the airplane prior to the accident. After the accident, the pilot and certificated flight instructor reported the wind was about 3 to 4 knots down the runway, with dust devils crossing the runway. ## Aircraft - Registration: [N4589M](https://openairdocs.org/aircraft/N4589M), registered now, S/N 11-92, built 1947 (OpenAirDocs) - Reported make and model: PIPER PA-11 - Registry model: [Piper PA-11](https://openairdocs.org/model/piper-pa-11) (registry code 7101102) (OpenAirDocs) - Registry engine: [Continental C85 series](https://openairdocs.org/engine/continental-c85-series) (registry code 17008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 11-92 - Airframe hours: 6521 - Engines: Lycoming O-235-C 105 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Morris Jerry W - Registered owner: Morris Jerry W - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 27, 2012, 20 hours before - Departed: KFMM, Ft. Morgan, CO - Destination: KFMM, Ft. Morgan, CO - Airport: KFMM, Ft Morgan Municipal, runway 32, 5,219 × 60 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: sport pilot; last flight review December 5, 2009; seat: front; flight hours: 1,613 total, 7 in this make and model, 7 in the last 90 days, 7 in the last 30 days, 7 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dawn - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 28 °F - Altimeter: 29.98 inHg - Observed at: KFMM ## Other investigations on N4589M (1) 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 ANC96LA022](https://openairdocs.org/ntsb/ANC96LA022), Dec 12, 1995: Piper PA-11 (N4589M), Delta Junction, AK, substantial damage. Probable cause: The pilot's inadequate preflight preparation/planning, and his improper in flight decision making. Factors associated with the accident are the gusty crosswinds and associated turbulence. ## Docket (1 files) The files NTSB released with the investigation on November 26, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=85066. 802 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 802 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378508&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.