# NTSB ERA19LA177: Zenith CH750, N750GZ, Savannah, TN, May 16, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: May 16, 2019, 14:35 local (19:35 UTC) - Place: Savannah, TN - Coordinates: 35.151111, -88.212219 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.1511&lon=-88.2122&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: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 99465 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA19LA177 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/99465/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=99465 - Page: https://openairdocs.org/ntsb/ERA19LA177 ## Probable cause The total loss of engine power due to a loss of all electrical power. Contributing to the accident was the inaccessible placement of the alternator circuit breaker and the construction of the airplane without a backup electrical source. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Electrical power system: dC generation system](https://openairdocs.org/ntsb-findings/01022430): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Ziebell Grant G ZENITH CH 750 STOL, 1 case](https://openairdocs.org/ntsb-findings/01022430/cases.md?model=05635UH), [All aircraft, 6 cases](https://openairdocs.org/ntsb-findings/01022430/cases.md) - [Electrical power system: dC power distribution system](https://openairdocs.org/ntsb-findings/01022460): Aircraft › Aircraft systems · Design (probable cause); cases with it: [Ziebell Grant G ZENITH CH 750 STOL, 1 case](https://openairdocs.org/ntsb-findings/01022460/cases.md?model=05635UH), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/01022460/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: [Ziebell Grant G ZENITH CH 750 STOL, 1 case](https://openairdocs.org/ntsb-events/332/sequence.md?model=05635UH), [All aircraft, 182 cases](https://openairdocs.org/ntsb-events/332/sequence.md) - [Approach: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Ziebell Grant G ZENITH CH 750 STOL, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=05635UH), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Ziebell Grant G ZENITH CH 750 STOL, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=05635UH), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot was conducting a personal flight in the experimental amateur-built airplane, and after departing the local area, noticed the DC electrical bus voltage decrease from 13.6 volts to 12.5 volts. He initiated a turn back to the airport and about 2 minutes later, the DC bus voltage decreased to 0 volts and the engine stopped producing power. The pilot performed a forced landing to an open field, during which the airplane sustained substantial damage. The airplane was constructed such that the engine was electrically dependent on a single alternator and a single battery to provide required electrical power to operate the fuel pump and ignition systems. Examination of the airplane revealed that the alternator circuit breaker, which was located behind the instrument panel and out of view of and inaccessible to the pilot, was tripped. Based on the pilot's description of events, it is likely that an electrical load drew an excessive current through the alternator circuit breaker, which resulted in it tripping and interrupting the electrical power supplied by the alternator. The engine's electrically-operated fuel and ignition systems continued to function on battery power for about 2 minutes before the engine stopped running. The pilot's reported inability to restore electrical power (and subsequently, engine power) at a low altitude resulted in the forced landing. ## Factual narrative On May 16, 2019, about 1435 central daylight time, an experimental amateur-built Zenith CH750 STOL, N750GZ, was substantially damaged when it was involved in an accident near Savannah-Hardin County Airport (SNH), Savannah, Tennessee. The pilot and passenger were not injured. The airplane was operated under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, he performed a preflight inspection of the airplane with no anomalies noted. He stated that he checked the battery voltage after engine start-up, then departed SNH. While in flight, he observed a drop in the direct current (DC) electrical bus voltage from a normal value of about 13.6 volts direct current (vdc) to about 12.5 vdc. He initiated a turn back to SNH and about 2 minutes later, the DC bus voltage dropped to 0 vdc and the engine stopped producing power. The pilot selected an open field and preformed a forced landing. After the accident, the pilot noted that the alternator in-line circuit breaker located under the instrument panel, was tripped. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed substantial damage to the firewall and additional damage to the nosewheel and rudder pedals. An inspection of the alternator circuit breaker revealed that its location underneath the instrument panel was not visible or accessible to reset during flight. The airplane was constructed such that the engine was electrically dependent on a single alternator and a single battery to provide required electrical power to operate the fuel pump and engine ignition systems. Following the accident, the pilot installed a backup battery in the airplane. ## Aircraft - Registration: [N750GZ](https://openairdocs.org/aircraft/N750GZ), registered now, S/N 75-10231, built 2017 (OpenAirDocs) - Reported make and model: ZENITH CH750 (STOL) - Registry model: [Ziebell Grant G ZENITH CH 750 STOL](https://openairdocs.org/model/ziebell-grant-g-zenith-ch-750-stol) (registry code 05635UH) (OpenAirDocs) - Registry engine: [Corvair 2700](https://openairdocs.org/engine/corvair-2700) (registry code 18005, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 75-10231 - Year built: 2018 - Airframe hours: 57.2 - Engines: Corvair 3.0 110 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, January 24, 2019, 6 hours before - Departed: SNH, Savannah, TN - Destination: SNH, Savannah, TN - Airport: SNH, Savannah-Hardin County - Equipment: Handheld GPS, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; private; airplane ratings: single-engine land; medical: sport pilot, with waivers/limitations; last flight review May 18, 2018; seat: left; restraint: 3-point; flight hours: 251.3 total, 58.7 in this make and model, 251.3 as pilot in command, 2.5 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 66 °F - Altimeter: 29.95 inHg - Observed at: SNH, 1 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 20190516004729A](https://openairdocs.org/incident/20190516004729A), May 16, 2019: Ziebell Grant G ZENITH CH 750 STOL, Savanah, TN, Substantial damage. Savannah, TN: N750GZ, experimental, reported loss of voltage and engine failure. Aircraft landed in a field approximately 1.3 miles from snh causing damage to… ## Docket (4 files) The files NTSB released with the investigation on January 19, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=99465. 9.9 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 8.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11173820&FileExtension=pdf&FileName=ERA19LA177%20NTSB%206120_Redacted-Rel.pdf - Pilot's statement (item 2, PDF, 1 page, 123 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10996930&FileExtension=pdf&FileName=Memorandum%20for%20Record-Pilot%20interview-Rel.pdf - FAA inspector statement (item 3, PDF, 1 page, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11172780&FileExtension=pdf&FileName=Memorandum%20for%20Record-FAA%20statement-Rel.pdf - Investgative photographs (item 4, PDF, 3 pages, 3 photos, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=10996940&FileExtension=pdf&FileName=Investigative%20Photographs%20-%20ERA19LA177-Rel.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.