# NTSB ANC16LA067: Helio H 295, N6464V, Fairbanks, AK, September 16, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 16, 2016, 08:20 local (16:20 UTC) - Place: Fairbanks, AK - Coordinates: 65.470001, -147.338333 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=65.4700&lon=-147.3383&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report July 26, 2017 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Wright Air Service, Federal Aviation Administration - NTSB case key (mKey): 94042 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC16LA067 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94042/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94042 - Page: https://openairdocs.org/ntsb/ANC16LA067 ## Probable cause Excessive side loads imposed on the tailwheel A-frame during the takeoff roll, which resulted in a separation of the tailwheel and the subsequent loss of directional control. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: nose/tail landing gear](https://openairdocs.org/ntsb-findings/01023220): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Helio H-295, 1 case](https://openairdocs.org/ntsb-findings/01023220/cases.md?model=4300802), [All aircraft, 185 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Helio H-295, 3 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=4300802), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Helio H-295, 1 case](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=4300802), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Helio H-295, 2 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=4300802), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Helio H-295, 5 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=4300802), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Helio H-295, 12 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4300802), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The airline transport pilot was departing from a remote unimproved airstrip. He stated that, as he initiated the takeoff, everything seemed normal. About 300 ft into the takeoff roll, the airplane veered sharply left, exited the airstrip, and impacted brush and trees, which resulted in substantial damage to the fuselage and left horizontal stabilator. A postaccident examination of the airplane revealed that the tailwheel had separated from its attachment point and folded underneath the empennage. Visual and magnified optical examinations revealed deformation and fracture patterns consistent with an overstress failure. Although fatigue cracks were observed in the fractured left arm of the tailwheel A-frame, they were relatively small and would not likely have caused a failure without abnormal loading. Additionally, the fractures in the left arm initiated not only at the fatigue cracks but also at locations away from the fatigue cracks, consistent with an overstress fracture. It is likely that the tailwheel A-frame fractured due to excessive side loads on the frame, which led to the tailwheel separating and the subsequent loss of control. ## Factual narrative On September 16, 2016, about 0820 Alaska daylight time, a tundra tire-equipped Helio Courier H-295 airplane, N6464V, sustained substantial damage following a loss of control and subsequent runway excursion during takeoff from a remote, unimproved airstrip near Fairbanks, Alaska. The airplane was being operated by Wright Air Service, Fairbanks, Alaska, as a visual flight rules (VFR) on-demand commercial flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135. The certificated airline transport pilot and one passenger were not injured. Visual meteorological conditions prevailed, and a VFR flight plan had been filed. During an interview with the National Transportation Safety Board (NTSB) investigator-in-charge on September 20, the pilot stated that everything seemed normal as he initiated the takeoff. About 300 feet into the takeoff roll, the airplane veered sharply to the left, exited the airstrip and impacted brush and trees, resulting in substantial damage to the fuselage and left horizontal stabilator. The initial examination of the airplane, reported by the pilot, revealed that the tailwheel separated from its attach point and folded underneath the empennage. A trench was visible in the airstrip's surface that began about 300 feet from the point where the takeoff roll was initiated and continued to where the airplane impacted the brush and trees. The tailwheel A-frame consisted of two arms extending forward of a flanged downtube, with a brace cross tube present between the two forward facing arms. The tailwheel A-frame was attached to the airframe at the forward ends of the arms, and to a shock absorber on the aft side of the down tube. Corner braces reinforced the attachments between the arms and the downtube. The corner brace between the left arm and the downtube was buckled and cracked, and the left arm was fractured where it was welded to the downtube. The tailwheel A-frame assembly was sent to the NTSB's Materials Laboratory in Washington D.C. for examination. An NTSB Senior Materials Engineer reported that visual and magnified optical examinations of the fractures in the left arm revealed a matte gray fracture on slant planes consistent with a ductile overstress fracture. However, a portion of the fracture surface had a fracture in a plane perpendicular to the surface across most of the fracture with small shear lips present. Two areas had no shear lips at the surface and were oxidized with smooth curving boundaries, consistent with fatigue. The right arm had a crack that was opened in the laboratory. Examination of the fracture revealed that a portion of the fracture surface at the upper side of the right arm was on a plane perpendicular to the surface and was oxidized with curving black arrest lines, features consistent with fatigue. The remainder of the fracture surface had matte gray features on slant planes across the thickness of the arm wall. The fatigue regions in the left and right arms were up to 0.016inch deep and 0.066 inch deep, respectively. The fracture surfaces where the brace tube between the arms had separated from the right arm were examined. The fracture features had matte gray features on slant planes consistent with ductile overstress fracture. In addition, fracture features where the shock absorber attachment ear fractured had features consistent with ductile overstress fracture. (Refer to the Materials Laboratory Factual Report in the public docket for further fracture information) The closest weather reporting facility was Fairbanks International Airport, Fairbanks, Alaska, about 42 miles south of the accident site. At 0753, an aviation routine weather report (METAR) from Fairbanks Airport, was reporting in part: wind from 050° at 4 knots; visibility, 10 statute miles; sky condition, broken clouds 5,500 feet, broken clouds 7,500 feet, broken clouds 15,000 feet; temperature, 39° F; dew point 37° F; altimeter, 29.36 inHG. ## Aircraft - Registration: [N6464V](https://openairdocs.org/aircraft/N6464V), registered now, S/N 1414, built 1969 (OpenAirDocs) - Reported make and model: HELIO H 295 - Registry model: [Helio H-295](https://openairdocs.org/model/helio-h-295) (registry code 4300802) (OpenAirDocs) - Registry engine: [Lycoming GO-480 series](https://openairdocs.org/engine/lycoming-go-480-series) (registry code 41527, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1414 - Year built: 1969 - Airframe hours: 6112.7 - Engines: LYCOMING GO-480 SERIES 295 horsepower reciprocating - Damage: Substantial damage - Flight: Part 135 - Operator: Wright Air Service - Registered owner: Bursiel Equipment Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 2, 2016 - Departed: Fairbanks, AK - Destination: Fairbanks, AK - Flight plan: VFR - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 5, 2016; seat: left; restraint: 4-point; flight hours: 12,000 total, 140 in this make and model, 11,000 as pilot in command, 350 in the last 90 days, 140 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 50° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: 5,500 ft broken - Temperature: 39 °F, dew point 37 °F - Altimeter: 29.36 inHg - Observed at: PAFA ## 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 20160916018609A](https://openairdocs.org/incident/20160916018609A), Sep 16, 2016: Helio H-295, Livengood, AK, Substantial damage. On September 16 2016 at 0801, the pilot in command with one passenger of a Helio H-295 flying for wrights air service was taking off from a grass airstrip next… ## Other investigations on N6464V (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 ANC15LA070](https://openairdocs.org/ntsb/ANC15LA070), Sep 13, 2015: Helio H 295 (N6464V), Delta Junction, AK, substantial damage. Probable cause: A partial loss of engine power during takeoff for reasons that could not be determined because postaccident examination of the airframe and engine did not reveal any anomalies that would have… ## Docket (4 files) The files NTSB released with the investigation on June 5, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94042. 8.7 MB in all. - Materials Laboratory Factual Report 17-022 (item 1, .PDF, 21 photos, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452841&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report%2017-022-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452842&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 3, .PDF, 338 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452843&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Photos (item 4, .PDF, 3 photos, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40452844&FileExtension=.PDF&FileName=Photos-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.