# NTSB ANC19LA024: Aeronca 7DC, N83391, Nome Creek, AK, June 12, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 11, 2019, 19:30 local (Jun 12, 2019, 03:30 UTC) - Place: Nome Creek, AK - Coordinates: 65.337219, -146.726104 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=65.3372&lon=-146.7261&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 99659 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC19LA024 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99659/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99659 - Page: https://openairdocs.org/ntsb/ANC19LA024 ## Probable cause The failure of the airplane's structural tubing due to corrosion, which resulted in a tailwheel separation and a subsequent loss of control. Also causal was the mechanic's failure to perform a detailed inspection of the aft fuselage during the most recent annual inspection. ## 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 · Attain/maintain not possible (probable cause) - [Inspection: scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520): Personnel issues › Task performance · Maintenance personnel (probable cause) - [Fuselage: frames (main fuselage)](https://openairdocs.org/ntsb-findings/01035311): Aircraft › Aircraft structures · Fatigue/wear/corrosion (probable cause) - [Fuselage: gear attach fittings (on fus)](https://openairdocs.org/ntsb-findings/01035343): Aircraft › Aircraft structures · Fatigue/wear/corrosion (probable cause) ## Analysis During landing on an unimproved runway, after the tailwheel contacted the ground, it’s mount failed, the rudder pedal jammed, and the airplane veered right. The pilot attempted to raise the tail to regain control with no effect. The airplane subsequently exited the intended landing area and came to rest in brush. A postaccident examination of the airplane revealed that the aft airframe tubing where the tailwheel was mounted to the airframe was corroded and fatigued, with cracks and discoloration from corrosion on the airframe. The airplane had flown 44.9 hours and 109 days had elapsed since its most recent annual inspection. Review of maintenance records revealed no discrepancies related to the area of the tailwheel mount. It is likely that the mechanic failed to conduct a detailed inspection in the aft fuselage area, which would have identified the corrosion. ## Factual narrative On June 12, 2019, about 1930 Alaska daylight time, an Aeronca 7DC (Champ) airplane, N83391, sustained substantial damage, during an off-airport landing, following a loss of control after the tailwheel of the airplane separated from the fuselage near Nome Creek, Alaska. The private pilot and sole occupant sustained no injuries. The airplane was registered to the pilot and operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a visual flight rules personal flight. Day visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated from the Fairbanks International Airport (FAI), Fairbanks, Alaska, about 1830. The pilot reported that, after selecting a dry, unimproved dirt airstrip to land, he performed a wheel landing. When he lowered the tail during the landing roll, the rudder pedal jammed, and the airplane veered right. He attempted to raise the tail to regain rudder control, with no effect. The airplane exited the intended landing area and was headed toward trees, he pulled the throttle to idle, and applied aft pressure on the control stick while applying the brakes. Subsequently, the airplane stopped short of the tree line in the brush. The pilot further reported that during a postaccident inspection, the tailwheel had failed at the forward attach mount point, the tailwheel spring had dug into the ground, and the broken tailwheel had caught the rudder and had jammed it. The airplane was examined on June 18, 2019 by an NTSB senior aviation accident investigator in Fairbanks. The examination revealed the aft portion of the airframe was corroded, with the airframe tubes discolored and damaged from the corrosion. The location where the tailwheel mounted to the airframe had failed and showed positive signs of corrosion throughout the tubing. The last inspection on the airplane performed was an annual inspection dated February 23, 2019. Since the inspection, 109 days had elapsed, and the airplane had flown 44.9 hours. During the annual inspection, the mechanic noted that he shimmed the rudder up to prevent chaffing on the tail spring. He also noted that he shimmed the tailwheel spring to help with the geometry of the tailwheel. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Part(s) separation from AC](https://openairdocs.org/ntsb-events/338) (defining event) - [Landing-flare/touchdown: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - [Landing-flare/touchdown: Runway excursion](https://openairdocs.org/ntsb-events/300) ## Aircraft - Registration: [N83391](https://openairdocs.org/aircraft/N83391), registered now, S/N 7AC2058, built 1946 (OpenAirDocs) - Reported make and model: Aeronca 7DC (No Series) - Registry model: [Aeronca 7DC](https://openairdocs.org/model/aeronca-7dc) (registry code 2110116) (OpenAirDocs) - Registry engine: [Continental C85 series](https://openairdocs.org/engine/continental-c85-series) (registry code 17008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 7AC2058 - Year built: 1946 - Airframe hours: 844.49 - Engines: Continental C-85-12 85 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 23, 2019, 45 hours before - Departed: FAI, Fairbanks, AK - Destination: Nome Creek, AK - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 30; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review September 24, 2018; seat: front; restraint: 3-point; flight hours: 121 total, 54 in this make and model, 76 as pilot in command, 39 in the last 90 days, 19 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 73 °F, dew point 37 °F - Observed at: PAFA, 43 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 20190612011199A](https://openairdocs.org/incident/20190612011199A), Jun 12, 2019: Aeronca 7DC, Nome Creek, AK, Substantial damage. The pilot landed his aircraft on an area along the Nome Creek in Alaska. On touchdown the tailwheel assembly broke and jammed the tailwheel to the left causing… ## Other investigations on N83391 (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 ANC23LA053](https://openairdocs.org/ntsb/ANC23LA053), Jul 13, 2023: Aeronca 7DC (N83391), Ninilchik, AK, substantial damage. Probable cause: A total loss of engine power due to a shift of a crankshaft main bearing, which resulted in a lack of lubrication and subsequent overheating and failure of the engine crankshaft. ## Docket (3 files) The files NTSB released with the investigation on November 21, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99659. 5.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478248&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Annual Inspection Entry (item 2, .PDF, 341 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478249&FileExtension=.PDF&FileName=Annual%20Inspection%20Entry-Master.PDF - Accident Pictures (item 3, .PDF, 6 photos, 964 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478250&FileExtension=.PDF&FileName=Accident%20Pictures-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.