# NTSB GAA17CA101: Maule MX 7, N56681, Willow, AK, December 15, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 15, 2016, 11:00 local (20:00 UTC) - Place: Willow, AK - Coordinates: 61.860279, -151.405548 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.8603&lon=-151.4055&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 7, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 94538 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA101 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94538/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94538 - Page: https://openairdocs.org/ntsb/GAA17CA101 ## Probable cause The pilot’s failure to ensure that the runway was clear of any obstacles before departure, which resulted in the airplane impacting a snowdrift. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Runway/land/takeoff/taxi surface: snow/slush/ice covered surface](https://openairdocs.org/ntsb-findings/03023015): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [Maule MX-7-235, 1 case](https://openairdocs.org/ntsb-findings/03023015/cases.md?model=5470207), [All aircraft, 219 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md) - [Planning/preparation](https://openairdocs.org/ntsb-findings/02061000): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Maule MX-7-235, 1 case](https://openairdocs.org/ntsb-findings/02061000/cases.md?model=5470207), [All aircraft, 113 cases](https://openairdocs.org/ntsb-findings/02061000/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Maule MX-7-235, 1 case](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=5470207), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Maule MX-7-235, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=5470207), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Takeoff: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Maule MX-7-235, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=5470207), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) ## Analysis The pilot of the tailwheel-equipped airplane reported that, during takeoff from a remote airstrip, the airplane impacted a snowdrift and was "launched" into the air. Subsequently, he heard something break. He added that the airplane appeared to be fine with no indications of a problem other than the left tire "looked a little off." The pilot returned to his original departure airport without further incident. During a postaccident examination, his mechanic discovered that the tubing in the bottom of the fuselage where the oleo strut attached to the main landing gear was broken. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. As a safety recommendation, the pilot added that walking the runway before takeoff might have revealed the snowdrift. ## Factual narrative The pilot of a tailwheel-equipped airplane reported that during takeoff from a remote airstrip, the airplane impacted a snowdrift and was "launched" into the air. Subsequently, he heard something break. He added that the airplane appeared to be fine with no indications of a problem other than the left tire "looked a little off". The pilot returned to his original departure airport without further incident. During a post-accident examination, his mechanic discovered that the tubing in the bottom of the fuselage where the olio strut attached to the main landing gear was broken. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. As a safety recommendation, the pilot added that walking the runway prior to takeoff might have revealed the snowdrift. ## Aircraft - Registration: [N56681](https://openairdocs.org/aircraft/N56681), registered now, S/N 10048C, built 1987 (OpenAirDocs) - Reported make and model: MAULE MX 7 (235) - Registry model: [Maule MX-7-235](https://openairdocs.org/model/maule-mx-7-235) (registry code 5470207) (OpenAirDocs) - Registry engine: [Lycoming L-540-T4B5](https://openairdocs.org/engine/lycoming-l-540-t4b5) (registry code 41563, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 10048C - Year built: 1987 - Airframe hours: 9266 - Engines: Lycoming IO-540 W1A5D 235 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Airworthiness certificate: Standard, Normal - Last inspection: AAIP, December 6, 2016 - Departed: UUO, WILLOW, AK - Destination: Willow, AK - Flight plan: VFR - Equipment: Stall warning system, Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review May 12, 2016; seat: left; restraint: 3-point; flight hours: 15,000 total, 8,300 in this make and model, 15,000 as pilot in command, 200 in the last 90 days, 20 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 4,600 ft overcast - Temperature: 18 °F, dew point 1 °F - Altimeter: 30.36 inHg - Observed at: PATK, 46 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 20161215022579A](https://openairdocs.org/incident/20161215022579A), Dec 15, 2016: Maule MX-7-235, Willow, AK, Substantial damage. Operator landed at remote strip and dropped off passengers. During take off hit a snow drift that launched aircraft into the air with a loud bang. Operator… ## Docket (2 files) The files NTSB released with the investigation on May 11, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94538. 2.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452107&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Photo (Courtesy of FAA) (item 2, .PDF, 1 photo, 274 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452108&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20FAA)-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.