# NTSB CEN17LA021: Zenith CH-750, N8681, Morristown, MN, October 20, 2016 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: October 20, 2016, 13:50 local (18:50 UTC) - Place: Morristown, MN - Coordinates: 44.268611, -93.469718 - Nearby events: https://openairdocs.org/map.md?lat=44.2686&lon=-93.4697&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report May 1, 2017 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 94252 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA021 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94252/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94252 - Page: https://openairdocs.org/ntsb/CEN17LA021 ## Probable cause A total loss of engine power due to fuel vapor lock. Contributing to the loss of engine power were the corrosion of the spark plugs and the spacing of the electrode gaps. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Aircraft](https://openairdocs.org/ntsb-findings/01050000): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-findings/01050000/cases.md?model=05634II), [All aircraft, 151 cases](https://openairdocs.org/ntsb-findings/01050000/cases.md) - [Ignition system: spark plugs/igniters](https://openairdocs.org/ntsb-findings/01057421): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-findings/01057421/cases.md?model=05634II), [All aircraft, 38 cases](https://openairdocs.org/ntsb-findings/01057421/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid condition; cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=05634II), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=05634II), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05634II), [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: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-events/440/sequence.md?model=05634II), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Delbert Voegele ZENITH CH-750, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=05634II), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The private pilot reported that he had started, warmed up, and then shut down the engine about 1 hour before the accident flight. Shortly after takeoff for the personal flight, the airplane's engine lost total power. Subsequently, the pilot conducted a forced landing on a hill, which resulted in substantial damage to the nose landing gear, fuselage, and left wing. The pilot said that he had fueled the airplane that morning with 82-octane automotive fuel that he had recently purchased from a service station. However, postaccident examination revealed that the fuel was yellow in color and smelled like "aged" automobile fuel. The top spark plugs appeared aged, and the electrodes were corroded, which could have affected engine performance. The airplane was not equipped with a fuel vapor return line to prevent fuel vapor lock. Given that old automotive fuel was found in the fuel system and that a fuel vapor return line had not been installed, it is likely that the engine lost power due to vapor lock. It is also likely that the corrosion of the spark plugs and the spacing of the electrode gaps contributed to the loss of engine power. ## Factual narrative October 20, 2016, about 1350 central daylight time (CDT), the pilot of a Zenith CH-750, N8681, made a forced landing in a field 3 miles northwest of Morristown, Minnesota, after the engine lost power. The pilot, the sole occupant on board, was seriously injured. The airplane was substantially damaged. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Visual meteorological conditions (VMC) prevailed at the time of the accident, and no flight plan had been filed. The local flight originated from a private airstrip in Morristown about 1340. The following is based on two interviews between Federal Aviation Administration (FAA) inspectors and the pilot. The pilot said he had fueled the airplane that morning with 82-octane automotive fuel that he had recently purchased from a service station. He started the engine and allowed it to warm up but had to shut the engine down when he was called away. He returned about an hour later, started the engine, and took off. When he reached an altitude of about 100 feet AGL, the engine lost power. He turned the electric fuel pump on. The engine restarted momentarily but failed to keep running. He did not remember if he turned the fuel selector valve to the opposite tank. After maneuvering to avoid cattle and a tree, the airplane touched down on its main landing gear. Due to the steepness of the hill and the grass, the airplane came to an abrupt halt. Examination of the airplane revealed the nose gear had collapsed, the fuselage was buckled, and the engine was knocked askew to the right. The left wing had separated from the fuselage and bore leading edge crushing. When asked what he thought may have happened, the pilot said he felt it was a vapor lock due to the time between the first and second engine starts and takeoff. He also stated that the engine had a safety feature that prevented it from starting if the throttle was out of the idle position. He felt that he could have gotten the engine running if he had brought the throttle back to idle but he failed to do so during the emergency. On October 28, 2016, the airplane and engine were examined at Wentworth Aircraft in Lakeville, Minnesota, under the auspices of a Federal Aviation Administration (FAA) inspector. Recovered fuel was yellow in color and had the aroma of "aged" automobile fuel. The top spark plugs were removed and examined. They appeared old and corroded at the electrode ends. The electrode gaps were not consistent. The number 3 plug appeared had a substantial gap, and the number 1 plug had a narrow gap. These were the only mechanical anomalies noted. It was also determined the airplane did not have a fuel vapor line installed. A Rotax Aircraft Engines flight safety representative verified a vapor lock was a possibility, especially since the owner had not installed a fuel vapor return line and old automotive fuel was found in the fuel system. He statedthat the condition and corrosion of the spark plugs and the spacing of the electrode gaps could also affect engine performance. He also stated the engine did not have a safety device installed that would prevent it from starting when the throttle was in other than the idle position. Examination of the maintenance records revealed the pilot had complied with Service Bulletin SB-912-053-UL on May 24, 2007, mandating the replacement of the fuel pump. However, there was no record that he had complied with SB-912-063-UL that mandated replacing the 5-year life-limit fuel pump. ## Aircraft - Registration: [N8681](https://openairdocs.org/deregistered/N8681-2017-03-01), registration cancelled 2017-03-01, S/N 75-8681, built 2015 (OpenAirDocs) - Reported make and model: ZENITH CH-750 - Registry model: [Delbert Voegele ZENITH CH-750](https://openairdocs.org/model/delbert-voegele-zenith-ch-750) (registry code 05634II) (OpenAirDocs) - Registry engine: [Rotax 912ULS series](https://openairdocs.org/engine/rotax-912uls-series) (registry code 55572, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 75-8681 - Year built: 2015 - Engines: Rotax 912ULS 100 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental light sport (Special) - Departed: NONE, Morristown, MN - Destination: NONE, Morristown, MN - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: serious; private; airplane ratings: single-engine land; medical: class 3; seat: left; restraint: 3-point; flight hours: 150 total, 150 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 43 °F - Altimeter: 30.17 inHg - Observed at: KOWA, 15 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 20161020022449A](https://openairdocs.org/incident/20161020022449A), Oct 20, 2016: Zenith CH-750, Morristown, MN, Substantial damage. Aircraft N8681, an experimental amateur-built Zenith CH-750, departed a private airstrip on the pilot?s farm. The aircraft achieved an approximate height of… ## Docket (11 files) The files NTSB released with the investigation on January 31, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94252. 3.9 MB in all. - FAA Inspector's Report (item 1, .PDF, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448832&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report-Master.PDF - FAA Interviews with Pilot (item 2, .PDF, 91 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448833&FileExtension=.PDF&FileName=FAA%20Interviews%20with%20Pilot-Master.PDF - E-Mail RE Starting the Rotax Engine (item 3, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448834&FileExtension=.PDF&FileName=E-Mail%20RE%20Starting%20the%20Rotax%20Engine-Master.PDF - E-Mail RE Vapor Lock (item 4, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448835&FileExtension=.PDF&FileName=E-Mail%20RE%20Vapor%20Lock-Master.PDF - E-Mail RE Mandatory Fuel Return Line (item 5, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448836&FileExtension=.PDF&FileName=E-Mail%20RE%20Mandatory%20Fuel%20Return%20Line-Master.PDF - E-Mail RE Fuel Pump Replacement (item 6, .PDF, 89 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448837&FileExtension=.PDF&FileName=E-Mail%20RE%20Fuel%20Pump%20Replacement-Master.PDF - Pertinent Service Bulletins RE Replacement of Fuel Pump for Rotax Engine Type 912 Series (item 7, .PDF, 861 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448838&FileExtension=.PDF&FileName=Pertinent%20Service%20Bulletins%20RE%20Replacement%20of%20Fuel%20Pump%20for%20Rotax%20Engine%20Type%20912%20Series-Master.PDF - New Fuel System Requirements, Vapor Lock Prevention (item 8, .PDF, 956 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448839&FileExtension=.PDF&FileName=New%20Fuel%20System%20Requirements,%20Vapor%20Lock%20Prevention-Master.PDF - FAA Depicted Flight Path (item 9, .PDF, 1 photo, 181 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448840&FileExtension=.PDF&FileName=FAA%20Depicted%20Flight%20Path-Master.PDF - Weather Reports and Records Pertinent to the Investigation (item 10, .PDF, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448841&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records%20Pertinent%20to%20the%20Investigation-Master.PDF - Report Photos (item 11, .PDF, 5 photos, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40448842&FileExtension=.PDF&FileName=Report%20Photos-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.