# NTSB CEN12CA044: Aviat A-1, N93HU, Wolverton, MN, October 20, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: October 20, 2011, 15:45 local (20:45 UTC) - Place: Wolverton, MN - Coordinates: 46.563056, -96.733612 - Nearby events: https://openairdocs.org/map.md?lat=46.5631&lon=-96.7336&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 27, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Minneapolis FSDO - NTSB case key (mKey): 82188 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12CA044 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82188/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82188 - Page: https://openairdocs.org/ntsb/CEN12CA044 ## Probable cause The pilot's inadvertent excessive braking during the landing roll due to momentary pain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Impairment/incapacitation](https://openairdocs.org/ntsb-findings/02012000): Personnel issues › Physical · Pilot (probable cause); cases with it: [Aviat A-1, 1 case](https://openairdocs.org/ntsb-findings/02012000/cases.md?model=2210302), [All aircraft, 40 cases](https://openairdocs.org/ntsb-findings/02012000/cases.md) - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Aviat A-1, 1 case](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=2210302), [All aircraft, 297 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [Aviat A-1, 2 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2210302), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that on the landing roll on a grass field, he experienced a sharp pain in his left leg as he was applying the brakes. He inadvertently applied excessive braking and the airplane nosed over. The airplane came to rest on its back and sustained substantial damage to the fuselage, rudder, and vertical stabilizer. The pilot reported no mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Factual narrative The pilot reported that while landing off-airport in a grass field, he experienced a sharp pain in his left leg as he was applying the brakes. This caused him to inadvertently apply excessive braking and the airplane nosed over. The airplane came to rest on its back and sustained substantial damage to the fuselage, rudder, and vertical stabilizer. The pilot reported no mechanical failures or malfunctions of the airplane. ## Aircraft - Registration: [N93HU](https://openairdocs.org/aircraft/N93HU), registered now, S/N 1249, built 1993 (OpenAirDocs) - Reported make and model: AVIAT INC A-1 - Registry model: [Aviat A-1](https://openairdocs.org/model/aviat-a-1) (registry code 2210302) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1249 - Airframe hours: 360 - Engines: LYCOMING O-360-A1D 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Last inspection: Annual, July 21, 2011 - Departed: D54, Fargo, ND - Destination: D54, Fargo, ND ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 28, 2010; seat: front; flight hours: 302 total, 151 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 50 °F - Altimeter: 28.81 inHg - Observed at: FAR, 20 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 20111020024839A](https://openairdocs.org/incident/20111020024839A), Oct 20, 2011: Sky International A-1, Wolverton, MN, Substantial damage. At approximately 0615 ddt on 10/21/2011, I received a telephone call from [privacy data omitted]. He was very apologetic and said he needed to report an… ## Other investigations on N93HU (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 ANC96LA064](https://openairdocs.org/ntsb/ANC96LA064), May 2, 1996: Aviat A-1 (N93HU), Togiak, AK, substantial damage. Probable cause: The pilot's failure to remove frost from the surface of the wings and his delay in aborting the takeoff. Factors in the accident were the presence of frost on the wings and a deteriorated climb… ## Docket (2 files) The files NTSB released with the investigation on November 18, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82188. 754 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 708 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358261&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation with pilot (item 2, .PDF, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40358267&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20pilot-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.