# NTSB CEN16LA369: Stinson V77, N715FB, Jordan, MN, September 14, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 14, 2016, 09:10 local (14:10 UTC) - Place: Jordan, MN - Coordinates: 44.668334, -93.632499 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.6683&lon=-93.6325&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 8, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 94011 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA369 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94011/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94011 - Page: https://openairdocs.org/ntsb/CEN16LA369 ## Probable cause A partial loss of engine power due to carburetor icing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=8631802), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate; cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=8631802), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Stinson VULTEE V-77, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=8631802), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The pilot was conducting a personal flight to break in the recently overhauled engine. After about 30 minutes, when the airplane was about 2,000 ft above ground level, the engine started to backfire and lose power. The pilot attempted to troubleshoot the problem by switching fuel tanks; adjusting the engine throttle, mixture, and propeller controls; and selecting the individual magneto positions, to no avail. He performed an emergency landing to a soft field; the airplane subsequently nosed over during the landing roll, and the rudder sustained substantial damage. Postaccident examinations of the airframe, engine, and magnetos found no mechanical malfunctions or failures that would have precluded normal operation. Weather conditions at the time of the accident were conducive to serious carburetor icing at cruise power. Thus, it is likely that the engine lost power due to serious carburetor icing. ## Factual narrative On September 14, 2016 about 0910 central daylight time (CDT), a Stinson V-77 airplane, N715FB, was substantially damaged during an accident near East Jordan, Minnesota. The airline transport pilot was not injured. The airplane was privately registered and operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, and no flight plan was filed. The local flight departed South St. Paul Municipal Airport-Richard E Fleming Field (SGS), Minnesota, about 0820. The pilot was conducting the flight to put additional break-in hours on a newly-installed engine. The engine had about 10 total hrs since overhaul and 2 hrs since the last inspection at the time of the accident. About 30 minutes after take off, and at 2,000 ft above the ground (AGL), the engine started to constantly backfire and lost power. The airplane was unable to maintain level flight due to the power loss. The pilot attempted to regain engine power; he switched fuel tanks, adjusted the engine throttle, fuel/ air mixture, and propeller controls, and selected the individual magneto positions. There was no subsequent increase of engine power or reduction of backfiring. The pilot performed an emergency landing to a soft field where the airplane nosed over during landing. The rudder sustained substantial damage. An on-scene examination of the airplane by the Federal Aviation Administration (FAA) inspector revealed that the fuel selector was in the left tank position, the magneto switch was in the "BOTH" position, the primer was in and locked, the mixture was in the "RICH" position, the throttle was in the "CLOSED" position, and the propeller control was approximately ¼ back from the full-forward position. An additional examination was conducted by the FAA inspector on October 5, 2016. The Bendix dual magneto timing was 34º before top-dead center (BTC) on the left and 30º BTC on the right. All spark plug leads were tight and in like-new condition. The magneto switch was checked and appeared to operate normally. Magneto lead continuity was confirmed. The magneto points were checked while rotating the propeller and they opened normally. Both magnetos sparked. Both coils appeared to have a good spark. The magneto was removed and bench tested. No anomalies were noted with the magneto. The fuel system was examined and small amounts of liquid consistent with 100LL fuel were recovered from the carburetor bowl and the airframe gascolator. The carburetor was examined and no anomalies were noted. No pre-impact anomalies were noted with the airframe or engine that would have contributed to a partial loss of power. The pilot reported a temperature of 50° F at the time of the accident. He did not know the dewpoint at the accident location. At 0853, the temperature and dewpoint at Minneapolis-St. Paul International/Wold-Chamberlain Airport (MSP), Minneapolis, Minnesota, located 25 miles northeast of the accidentsite, were reported as 54° F and 45° F respectfully at 0853. According to the carburetor icing probability chart in FAA Special Airworthiness Information Bulletin CE-09-35, these conditions were conducive to serious icing at cruise power. ## Aircraft - Registration: [N715FB](https://openairdocs.org/aircraft/N715FB), registered now, S/N 77-443, built 1944 (OpenAirDocs) - Reported make and model: STINSON V77 (NO SERIES) - Registry model: [Stinson VULTEE V-77](https://openairdocs.org/model/stinson-vultee-v-77) (registry code 8631802) (OpenAirDocs) - Registry engine: [Lycoming R680-13](https://openairdocs.org/engine/lycoming-r680-13) (registry code 42408, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 77-443 - Year built: 1944 - Airframe hours: 158 - Engines: LYCOMING R680-13 300 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 24, 2016 - Departed: SGS, SOUTH ST PAUL, MN - Destination: SGS, SOUTH ST PAUL, MN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; flight instructor, airline transport, commercial, flight engineer; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review April 28, 2015; seat: left; restraint: 3-point; flight hours: 16,000 total, 281 in this make and model, 10,800 as pilot in command, 8 in the last 90 days, 3 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 3 knots - Visibility: 10 statute miles - Temperature: 54 °F, dew point 45 °F - Altimeter: 30.34 inHg - Observed at: MSP, 25 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 20160914018309A](https://openairdocs.org/incident/20160914018309A), Sep 14, 2016: Stinson VULTEE V-77, Jordan, MN, Substantial damage. Pilot stated he had departed sgs approximately 40 minutes prior to experiencing engine roughness and apparent loss of power. The engine had been recently… ## Docket (6 files) The files NTSB released with the investigation on April 24, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94011. 2.0 MB in all. - FAA Emails (item 1, .PDF, 100 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483101&FileExtension=.PDF&FileName=FAA%20Emails-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 711 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483102&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Exam Notes (item 3, .PDF, 69 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483103&FileExtension=.PDF&FileName=FAA%20Exam%20Notes-Master.PDF - Magneto Test Results (item 4, .PDF, 318 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483104&FileExtension=.PDF&FileName=Magneto%20Test%20Results-Master.PDF - Photos (item 5, .PDF, 3 photos, 715 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483105&FileExtension=.PDF&FileName=Photos-Master.PDF - FAA SAIB (item 6, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40483106&FileExtension=.PDF&FileName=FAA%20SAIB-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.