# NTSB GAA19CA505: Pipistrel Sinus 912, N331AV, Oxford, FL, August 22, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 22, 2019, 20:45 UTC - Place: Oxford, FL - Coordinates: 28.940277, -82.052223 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.9403&lon=-82.0522&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 16, 2020 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 100127 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA505 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100127/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100127 - Page: https://openairdocs.org/ntsb/GAA19CA505 ## Probable cause The pilot’s continued use of battery power during a nonpowered flight in a powered-glider, which depleted the battery to a level that was insufficient to power the starter during the engine restart sequence and resulted in a forced landing to a soft field and a subsequent nose-over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Electrical power system: battery/charger](https://openairdocs.org/ntsb-findings/01022432): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [All aircraft, 37 cases](https://openairdocs.org/ntsb-findings/01022432/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Effect on operation (probable cause); cases with it: [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. - [Landing: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096) (defining event); cases with it: [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that he was building hours in the powered-glider to prepare for his glider instructor rating examination. He departed the airport with power and climbed to the west to chase thermals. After the powered-glider reached 4,000 ft above ground level (agl), he shut down the engine, left the battery power on, and continued to climb to 4,500 ft agl. After 30 minutes, he attempted to restart the engine, but the starter only cranked the engine briefly, and the propeller travelled one full revolution and then stopped. After another unsuccessful engine start attempt and with the glider too far away to glide back to the airport, the pilot located a field for a forced landing. During the landing roll, the main landing gear wheels dug into the soft field, and the powered-glider nosed over and then came to rest inverted, which resulted in substantial damage to the engine mount truss. Postaccident examination of the powered-glider revealed that the single battery was depleted to a level that was insufficient to power the starter during the engine restart sequence. The pilot reported that there were no preaccident malfunctions or failures with the airframe or engine that would have precluded normal operation. ## Factual narrative The flight instructor reported that he was building hours in the powered glider in preparation for his glider instructor rating examination. He departed the airport with power and climbed to the west to chase thermals. After reaching 4,000 ft. above ground level (agl), he shut down the engine, left battery power on, and continued to climb to 4,500 ft. After 30 minutes, he attempted to restart the engine, but the starter only cranked the engine briefly and the propeller travelled 1 full revolution then stopped. After another unsuccessful engine start attempt, and too far away to glide back to the airport, he located a field for a forced landing. During the landing roll, the main landing gear wheels dug into the soft field and the glider nosed over, coming to rest inverted. A post-accident examination revealed that the single battery was depleted as it powered the avionics during the non-powered flight. Its depleted level was insufficient to power the starter during the engine restart sequence. The powered glider sustained substantial damage to the engine mount truss. The pilot reported that there were no preimpact malfunctions or failures to the airframe or engine that would have precluded normal operation. ## Aircraft - Registration: N331AV (not matched to a registry record) - Reported make and model: Pipistrel SINUS 912 (No Series) - Category: Airplane - Serial number: 736 SFN 912 LSA - Year built: 2015 - Engines: Rotax reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: San Antonio Light Sport Aircraft Inc - Registered owner: San Antonio Light Sport Aircraft Inc - Airworthiness certificate: Special, Experimental light sport (Special); Standard, Normal - Flight plan: Unknown - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; private, flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: left; flight hours: 2,700 total, 8 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 100° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 73 °F - Altimeter: 30.03 inHg - Observed at: KVVG, 5 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). - [Incident 20190822012149I](https://openairdocs.org/incident/20190822012149I), Aug 22, 2019: Pipistrel SINUS 912, Oxford, FL, Substantial damage. Aircraft is a motor-glider, pilot was soaring for 30 minutes then attempted to start engine with no success, the loss of lift pushed him into landing in a… ## Docket (3 files) The files NTSB released with the investigation on April 20, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100127. 317 KB in all. - Pilot Statement (item 1, .PDF, 91 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482627&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - FAA Statement (item 2, .PDF, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482628&FileExtension=.PDF&FileName=FAA%20Statement-Master.PDF - Accident Photo (item 3, .PDF, 133 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482629&FileExtension=.PDF&FileName=Accident%20Photo-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.