# NTSB ANC13LA049: Maule M-6-235, N56464, Big Lake, AK, May 19, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 19, 2013, 11:30 local (19:30 UTC) - Place: Big Lake, AK - Coordinates: 61.389999, -149.838882 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.3900&lon=-149.8389&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 11, 2013 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration - NTSB case key (mKey): 86967 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC13LA049 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86967/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86967 - Page: https://openairdocs.org/ntsb/ANC13LA049 ## Probable cause The pilot’s execution of a hard landing, which resulted in the overstress fracture of the right main axle housing and the subsequent nosedown. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Maule M-6-235, 7 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=5460160), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Landing gear system: main gear strut/axle/truck](https://openairdocs.org/ntsb-findings/01023213): Aircraft › Aircraft systems · Capability exceeded; cases with it: [Maule M-6-235, 1 case](https://openairdocs.org/ntsb-findings/01023213/cases.md?model=5460160), [All aircraft, 86 cases](https://openairdocs.org/ntsb-findings/01023213/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [Maule M-6-235, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=5460160), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Maule M-6-235, 2 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=5460160), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Maule M-6-235, 3 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=5460160), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Maule M-6-235, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=5460160), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot was practicing stop-and-go landings on the gravel-covered runway. Upon touchdown, the right main gear separated at the axle housing, which pivoted the airplane to the right as the main landing gear leg dug into the runway. The airplane subsequently nosed down and came to rest on the propeller spinner and left wing. The airplane sustained substantial damage to the left wing and lift struts. A postaccident examination revealed that the right main landing gear axle separated at the axle housing and main landing gear leg attachment point. Visual and magnified optical examinations of the fractured surfaces revealed features consistent with a bending overstress fracture, indicating that the pilot most likely executed a hard landing, which resulted in the fracture of the right main axle housing and the subsequent nosedown. ## Factual narrative On May 19, 2013, about 1130 Alaska daylight time, a tundra-tire and tailwheel-equipped Maule M-6-235 airplane, N56464, sustained substantial damage while landing at the Goose Bay Airport, about 9 miles south of Big Lake, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) personal flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The airline transport pilot was not injured. Visual meteorological conditions prevailed and a VFR military flight plan had been filed. The flight departed Elmendorf Air Force Base about 0830. During a telephone conversation with the National Transportation Safety Board investigator-in-charge (NTSB) on May 19, the pilot stated that he was practicing stop-and-go landings on the gravel covered runway at the Goose Bay Airport. Upon touchdown, the right main gear separated at the axle housing, which pivoted the airplane to the right as the main landing gear leg dug into the gravel covered runway. The airplane subsequently nosed down, coming to rest on the propeller spinner and left wing. The airplane sustained substantial damage to the left wing and lift struts. The pilot noted that the airplane was equipped with 35-inch tundra tires. A postaccident examination, by the pilot, revealed the right main landing gear axle separated at the axle housing to main landing gear leg attach point. A Senior Safety Board Metallurgist reported that visual and magnified optical examination of the fractured surfaces revealed features consistent with a bending overstress fracture. (A synopsis of the NTSB Metallurgist's case review is included in the public docket for this accident.) ## Aircraft - Registration: [N56464](https://openairdocs.org/deregistered/N56464-2014-12-16), registration cancelled 2014-12-16, S/N 7416C, built 1982 (OpenAirDocs) - Reported make and model: MAULE M-6-235 - Registry model: [Maule M-6-235](https://openairdocs.org/model/maule-m-6-235) (registry code 5460160) (OpenAirDocs) - Registry engine: [Lycoming IO-540-W1A5D](https://openairdocs.org/engine/lycoming-io-540-w1a5d) (registry code 41658, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7416C - Airframe hours: 4000 - Engines: Lycoming IO-540 235 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Vaught Timothy R - Registered owner: Vaught Timothy R - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 1, 2013 - Departed: PAED, Anchorage, AK - Destination: PAED, Anchorage, AK - Flight plan: VFR - Airport: Z40, Goose Bay, runway 08, 3,000 × 75 ft, gravel ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 40; injuries: none; military, commercial, flight instructor, airline transport; airplane ratings: multi-engine land; instrument ratings: helicopter, airplane; medical: class 2, without waivers/limitations; seat: left; flight hours: 4,100 total, 20 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 6 knots - Visibility: 10 statute miles - Temperature: 41 °F, dew point 10 °F - Altimeter: 30.46 inHg - Observed at: PAMR, 12 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 20130519009649A](https://openairdocs.org/incident/20130519009649A), May 19, 2013: Maule M-6-235, Wasilla, AK, Substantial damage. Airman was conducting stop and go's at the goose bay airport, Alaska. Prior to touchdown before the accident, the airman began reducing power at approximately… ## Docket (5 files) The files NTSB released with the investigation on August 23, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86967. 921 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 371 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40393491&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Materials Laboratory Synopsis and Photo (1 Embedded Image) (item 2, .PDF, 1 photo, 226 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397788&FileExtension=.PDF&FileName=Materials%20Laboratory%20Synopsis%20and%20Photo%20(1%20Embedded%20Image)-Master.PDF - Evidence Control Form (item 3, .PDF, 155 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397908&FileExtension=.PDF&FileName=Evidence%20Control%20Form-Redacted.PDF - Retention / Release of Wreckage Form (item 4, .PDF, 89 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397910&FileExtension=.PDF&FileName=Retention%20%2F%20Release%20of%20Wreckage%20Form-Redacted.PDF - Retention / Release of Wreckage Form (item 5, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397911&FileExtension=.PDF&FileName=Retention%20%2F%20Release%20of%20Wreckage%20Form-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.