# NTSB WPR12LA409: Great Lakes 2T-1A-2, N3702F, Monroe, WA, September 8, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 8, 2012, 13:30 local (20:30 UTC) - Place: Monroe, WA - Coordinates: 47.84, -121.970275 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=47.8400&lon=-121.9703&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-aerobatics: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report December 15, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 84987 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA409 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84987/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84987 - Page: https://openairdocs.org/ntsb/WPR12LA409 ## Probable cause A loss of engine power during cruise flight for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Great Lakes 2T-1A-2, 2 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=3910101), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Effect on equipment; cases with it: [Great Lakes 2T-1A-2, 1 case](https://openairdocs.org/ntsb-findings/03023020/cases.md?model=3910101), [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-aerobatics: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Great Lakes 2T-1A-2, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=3910101), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Great Lakes 2T-1A-2, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=3910101), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Great Lakes 2T-1A-2, 4 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=3910101), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot/owner reported that, after completing several aerobatic maneuvers, he and the flight instructor were returning to the departure airport when the engine began to lose power. The pilot made several attempts to regain engine power but was unsuccessful, and he then asked the flight instructor to fly the airplane. The flight instructor set the airplane for best glide and made a forced landing in a freshly plowed open field. During the landing on soft terrain, the main landing gear sank into the ground, and the airplane nosed over. The engine ran normally during an engine test run, and postaccident examination of the engine revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. ## Factual narrative On September 8, 2012, about 1330 Pacific daylight time, a Great Lakes 2T-1A-2, N3702F biplane, experienced a loss of engine power while maneuvering, and the pilot made a forced landing in an open field near Monroe, Washington. The pilot/owner and certified flight instructor (CFI) operated the airplane under the provisions of 14 Code of Federal Regulations Part 91 as a local area aerobatics instructional flight. The pilot/owner and CFI were not injured. The airplane was substantially damaged. Visual meteorological conditions prevailed for the flight, and no flight plan had been filed. The flight departed Harvey Field Airport (S43), Snohomish, Washington, about 1245.According to the pilot/owner, the purpose of the flight was to improve his aerobatic skills. He spent a couple of hours on the ground with the CFI going over the maneuvers and flight, and then they went out to the airplane. The CFI was seated in the front, and the pilot was seated in the rear. Start up, taxi, and run up were all normal, and they departed the airport to the north. They flew to a valley that was situated between Monroe and Duvall and commenced with a series of aerobatic maneuvers that included advanced stalls, slow flight, aileron rolls, and inverted emergency roll recovery procedures. Once the aerobatic maneuvers were completed, they headed back toward S43. The pilot reported that the airplane did not feel right to him, and shortly thereafter, the engine began to lose power. He adjusted the mixture and throttle; however, this did not have any effect on the engine. The engine quit, and he asked the CFI to fly the airplane while he unsuccessfully attempted to restart the engine. The pilot stated that the CFI made a successful 3-point landing, but during the rollout on soft dirt, the airplane landing gear sunk in and the airplane went over onto its back, which resulted in structural damage to the rudder and vertical stabilizer. According to the CFI's written statement, after about 40 minutes of flying they began the flight back toward S43. The CFI stated that in level cruise flight, the engine started to show signs of a loss of power. The pilots decided to continue toward S43 and remain over open fields. After the pilot was not able to return full power to the engine, he asked the CFI to fly the airplane. The CFI set the airplane up for best glide and identified a plowed field to make the forced landing. The CFI reported that they were at 3,000 feet when the engine quit. Following a successful 3-point landing and roll out, as the airplane slowed, the main landing gear sunk into the freshly plowed field and nosed over onto its back. A Federal Aviation Administration (FAA) inspector examined the airplane engine, along with maintenance personnel. The report is attached to the public docket for this accident. A visual examination of the engine revealed no obvious damage and the engine controls were manipulated to their respective minimum and maximum stops with no bindingnoted. A visual inspection of the exhaust and induction systems revealed no blockages. Fuel from the quick drains at the header tank was taken with no contaminants noted; it smelled and appeared to be 100 low-lead aviation fuel. An engine run was performed, and the engine appeared to run normally with no mechanical anomalies. ## Aircraft - Registration: [N3702F](https://openairdocs.org/aircraft/N3702F), registered now, S/N 0739, built 1976 (OpenAirDocs) - Reported make and model: GREAT LAKES 2T-1A-2 - Registry model: [Great Lakes 2T-1A-2](https://openairdocs.org/model/great-lakes-2t-1a-2) (registry code 3910101) (OpenAirDocs) - Registry engine: [Lycoming AEIO-360 series](https://openairdocs.org/engine/lycoming-aeio-360-series) (registry code 41522, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 0739 - Airframe hours: 799.03 - Engines: LYCOMING AEIO-360-B1GG 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Lakes Loopers LLC - Registered owner: Lakes Loopers LLC - Airworthiness certificate: Standard, Aerobatic - Last inspection: Annual, May 7, 2012, 799.03 hours before - Departed: S43, Snohomish, WA - Destination: S43, Snohomish, WA - Airport: S43, Harvey Field Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 44; injuries: none; flight instructor; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 2, 2011; seat: front; flight hours: 5,500 total, 1 in this make and model - Pilot; age 60; injuries: none; private; airplane ratings: single-engine land, single-engine sea; medical: with waivers/limitations; last flight review March 25, 2012; seat: rear; flight hours: 479 total, 148 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 46 °F - Altimeter: 29.95 inHg - Observed at: PAE, 19 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 20120908019359A](https://openairdocs.org/incident/20120908019359A), Sep 8, 2012: Great Lakes 2T-1A-2, Monroe, WA, Substantial damage. After engine failure force landed in soft field aircraft rolled onto back as it slowed. ## Other investigations on N3702F (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 OAK78DVD02](https://openairdocs.org/ntsb/OAK78DVD02), Oct 8, 1977: Great Lakes 2THA2 (N3702F), Oakland, CA, substantial damage ## Docket (3 files) The files NTSB released with the investigation on October 29, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84987. 4.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Searles (item 1, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418296&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Searles-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Allen (item 2, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418297&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Allen-Redacted.PDF - FAA Aircraft/Engine Inspection Report (item 3, .PDF, 340 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40418298&FileExtension=.PDF&FileName=FAA%20Aircraft%2FEngine%20Inspection%20Report-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.