# NTSB WPR10LA432: Stinson JR. S, N12164, Lake Stevens, WA, August 28, 2010 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 28, 2010, 13:20 local (20:20 UTC) - Place: Lake Stevens, WA - Coordinates: 48, -121.949996 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=48.0000&lon=-121.9500&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Electrical system malf/failure](https://openairdocs.org/ntsb-events/332) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed, report January 25, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 77110 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA432 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77110/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77110 - Page: https://openairdocs.org/ntsb/WPR10LA432 ## Probable cause A total loss of engine power during cruise flight, which resulted from a magneto switch failure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Ignition system: magneto/distributor](https://openairdocs.org/ntsb-findings/01057414): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-findings/01057414/cases.md?model=8630404), [All aircraft, 101 cases](https://openairdocs.org/ntsb-findings/01057414/cases.md) - [Object/animal/substance: fence/fence post](https://openairdocs.org/ntsb-findings/03022047): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-findings/03022047/cases.md?model=8630404), [All aircraft, 313 cases](https://openairdocs.org/ntsb-findings/03022047/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Electrical system malf/failure](https://openairdocs.org/ntsb-events/332) (defining event); cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-events/332/sequence.md?model=8630404), [All aircraft, 182 cases](https://openairdocs.org/ntsb-events/332/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=8630404), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Approach: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=8630404), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Stinson JR. S, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=8630404), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that, after cruising for about 30 minutes, the engine suddenly lost all power. During the forced landing in an open field, the airplane impacted a fence and then the ground. An examination of the airplane revealed that the engine’s magneto switch had failed. The switch was original equipment in the airplane, which was manufactured 79 years prior to the accident. The pilot reported no known maintenance history or malfunction of the magneto switch prior to the accident. ## Factual narrative On August 28, 2010, about 1320 Pacific daylight time, a Stinson JR.S, N12164, registered to a private individual and operated by the pilot, collided with obstacles during a forced landing near Lake Stevens, Washington. The airplane was substantially damaged during the impact sequence and the subsequent ground impact. The private pilot and one passenger were not injured; a second passenger received minor injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The 14 Code of Federal Regulations (CFR) Part 91 personal flight originated from Snohomish, Washington, about 1245. The pilot reported to the National Transportation Safety Board investigator that he was on a local area flight with family members. Upon departure, the airplane contained about 28 gallons of fuel. While cruising, the airplane's engine suddenly lost all power. The pilot stated that he attempted to restart the engine but was not successful. The propeller continued windmilling during the pilot's efforts at restarting the engine. The pilot made a forced landing in a nearby open field. During landing, the airplane collided with barbed wire and a fence. While decelerating in the field, additional objects were observed, and the pilot sharply turned the airplane. The left main landing gear separated from the airplane, and the outboard portion of the left wing impacted the ground and the wing spars were broken. The pilot subsequently informed the Safety Board investigator that an examination of the airplane revealed its magneto switch had failed. The switch was original equipment in the airplane, and it had no known maintenance history. The switch had likely been in the airplane since 1931, when the airplane was built. The switch had no known history of malfunction. The pilot opined that its internal contacts had just worn out. ## Aircraft - Registration: [N12164](https://openairdocs.org/aircraft/N12164), registered now, S/N 8102, built 1931 (OpenAirDocs) - Reported make and model: STINSON JR. S - Registry model: [Stinson JR. S](https://openairdocs.org/model/stinson-jr-s) (registry code 8630404) (OpenAirDocs) - Registry engine: [Lycoming R680](https://openairdocs.org/engine/lycoming-r680) (registry code 41540, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 8102 - Airframe hours: 2058 - Engines: LYCOMING R680-13 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 28, 2010 - Departed: S43, Snohomish, WA - Destination: S43, Snohomish, WA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review March 15, 2009; seat: left; flight hours: 606 total, 7 in this make and model, 515 as pilot in command, 2 in the last 90 days, 0 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 4 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 70 °F ## 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 20100828042529A](https://openairdocs.org/incident/20100828042529A), Aug 28, 2010: Stinson JR. S, Lake Stevens, WA, Substantial damage. N12164 departed from harvey field, snohomish, WA (S43) 20 – 30 minutes into the flight during cruise flight the engine quite without warning. Pilot states he… ## Docket (2 files) The files NTSB released with the investigation on October 31, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77110. 315 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 272 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40336178&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation - Pilot (item 2, .PDF, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40360839&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%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.