# NTSB CEN21LA156: Cessna 170, N9515A, Poplar Bluff, MO, March 9, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: March 9, 2021, 12:15 local (18:15 UTC) - Place: Poplar Bluff, MO · Harvested Cornfield - Coordinates: 36.8544, -90.4375 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.8544&lon=-90.4375&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: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: Federal Aviation Administration - St. Louis FSDO - NTSB case key (mKey): 102750 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA156 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102750/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102750 - Page: https://openairdocs.org/ntsb/CEN21LA156 ## Probable cause The pilot’s decision to make a precautionary landing in a field that contained soft terrain, which resulted in the airplane nosing over. Contributing to the accident was the pilot’s decision to fly without a printed VFR sectional chart to identify the location of the destination airport. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: flight planning/navigation](https://openairdocs.org/ntsb-findings/02061025): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 170A, 1 case](https://openairdocs.org/ntsb-findings/02061025/cases.md?model=2072304), [All aircraft, 179 cases](https://openairdocs.org/ntsb-findings/02061025/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 170A, 33 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072304), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Use of equip/info: use of charts](https://openairdocs.org/ntsb-findings/02063025): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 170A, 1 case](https://openairdocs.org/ntsb-findings/02063025/cases.md?model=2072304), [All aircraft, 10 cases](https://openairdocs.org/ntsb-findings/02063025/cases.md) - [Perception/orientation/illusion: geographic disorient (lost)](https://openairdocs.org/ntsb-findings/02022030): Personnel issues › Psychological · Pilot (probable cause); cases with it: [Cessna 170A, 1 case](https://openairdocs.org/ntsb-findings/02022030/cases.md?model=2072304), [All aircraft, 27 cases](https://openairdocs.org/ntsb-findings/02022030/cases.md) - [Terrain: wet/muddy terrain](https://openairdocs.org/ntsb-findings/03021035): Environmental issues › Physical environment · Effect on equipment (probable cause); cases with it: [Cessna 170A, 1 case](https://openairdocs.org/ntsb-findings/03021035/cases.md?model=2072304), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Cessna 170A, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=2072304), [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: [Cessna 170A, 3 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072304), [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: [Cessna 170A, 14 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072304), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot was conducting a cross-country flight and became lost as he neared his intended destination. During the flight, the pilot navigated via dead-reckoning and following roads. He occasionally referenced a mobile phone application to verify the airplane’s position on a digitized visual flight rules (VFR) sectional chart. The pilot did not have traditional paper VFR sectional charts to navigate with, if his mobile phone’s battery became depleted during the flight. Although he had access to a handheld GPS device, he did not use the device to navigate during the flight. About 15-20 minutes before reaching the intended destination, the pilot’s mobile phone powered off after its battery became depleted. The pilot then inserted the GPS power adapter into the airplane’s cigarette-lighter socket, but the GPS device did not power-on. The pilot continued on the current heading that took the airplane over his intended destination, but he could not locate the airport and subsequently decided to make an off-airport precautionary landing before the airplane ran out of fuel. The pilot landed the airplane in what he believed to be a suitable field; however, after touchdown, the airplane’s main landing gear dug into soft terrain and the airplane nosed over. The airplane sustained substantial damage to the vertical stabilizer and the engine mounts. Postaccident examination and testing did not reveal any electrical system anomalies that would have prevented the pilot from using the airplane’s cigarette-lighter socket as a power source for his mobile phone and handheld GPS during the flight. Additional bench testing of the alternator, voltage regulator, and battery did not reveal any anomalies that would have prevented normal operation of the airplane’s electrical charging system. ## Factual narrative On March 9, 2021, about 1215 central standard time, a Cessna 170A, N9515A, was substantially damaged when it was involved in an accident near Poplar Bluff, Missouri. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that he departed Shawnee Regional Airport (SNL), Shawnee, Oklahoma, about 0900, for the cross-country flight to Poplar Bluff Regional Business Airport (POF), Poplar Bluff, Missouri. The airplane was equipped with a communication radio, but it was not equipped with very high frequency omni-directional range (VOR) equipment or a transponder. Although he had access to a handheld Garmin GPSmap 396 device, the pilot did not use it to navigate during the flight. The pilot stated that he navigated via dead-reckoning and following roads. He occasionally referenced a mobile phone application to verify the airplane’s position on a digitized visual flight rules (VFR) sectional chart. The pilot acknowledged that he did not have traditional paper VFR sectional charts to navigate with if his mobile phone’s battery became depleted during the flight. About 15-20 minutes before reaching Poplar Bluff, Missouri, the pilot’s mobile phone powered off after its battery became depleted. The pilot stated that he then inserted the Garmin adapter into the airplane’s cigarette-lighter socket, but the GPS device did not power on. The pilot continued flying his current heading, which took him directly over the city of Poplar Bluff, Missouri. The pilot did not see the airport to the east of the city, so he turned and flew a couple miles south of the city before he made a 180° course reversal and flew over the city northbound. After flying several miles north of the city, he decided to locate a suitable field for a precautionary landing due to the airplane’s low fuel status. The left fuel tank gauge indicated “empty” and he estimated that the airplane had about 10 minutes of fuel remaining in the right fuel tank. He turned the airplane into the wind and landed in what he believed to be a suitable field. The pilot stated that the engine was still running throughout the precautionary landing. After touchdown, the airplane rolled about 200-300 ft before the main landing gear dug into the soft terrain and the airplane nosed over. The airplane sustained substantial damage to the vertical stabilizer and the engine mounts. During a telephone interview, the National Transportation Safety Board investigator asked the pilot to connect the Garmin GPSmap 396 device to his vehicle’s 12-volt direct current (DC) cigarette-lighter socket by means of the Garmin cigarette-lighter adapter. The GPS device automatically powered-on when connected to the power source, with and without the device’s battery installed. When disconnected from the power source, the GPS device did not power-on with battery installed. The last known position displayed on the GPS device was from a flight completed two daysbefore the accident. The airplane wreckage was recovered to a secured location where it was examined by two Federal Aviation Administration (FAA) airworthiness inspectors. The airframe battery was removed from the airplane during wreckage recovery. The 12-volt battery was not an aviation-certified battery and was consistent with a motorcycle battery. Without any electrical load, the battery had 12.45 volts when tested with a digital multimeter. The battery had 11.8 volts when it was connected to an automotive battery tester that subjected the battery to a 5-second electrical load. The battery was then reconnected to the airplane and, when the master switch was turned on, the communication radios powered on and the cigarette-lighter socket had 12.45 volts when measured with a digital multimeter. The FAA inspector inserted his personal USB charger adapter into the cigarette-lighter socket and confirmed that there was sufficient power to charge his mobile phone. Additional bench testing of the alternator, voltage regulator, and battery did not reveal any anomalies that would have prevented normal operation of the airplane’s electrical system. ## Aircraft - Registration: [N9515A](https://openairdocs.org/deregistered/N9515A-2023-11-27), registration cancelled 2023-11-27, S/N 19383, built 1950 (OpenAirDocs) - Reported make and model: CESSNA 170 (A) - Registry model: [Cessna 170A](https://openairdocs.org/model/cessna-170a) (registry code 2072304) (OpenAirDocs) - Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 19383 - Year built: 1950 - Airframe hours: 2717 - Engines: Continental O-300-A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 12, 2021 - Departed: SNL, Shawnee, OK - Destination: POF, Poplar Bluff, MO - Equipment: Handheld GPS, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 74; injuries: none; flight instructor, commercial; airplane ratings: single-engine land; medical: basicmed, unknown; last flight review January 19, 2021; seat: left; restraint: lap only; flight hours: 1,750 total ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 18 knots, gusting 30 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 66 °F, dew point 43 °F - Altimeter: 30.32 inHg - Observed at: POF, 7 nm away - METAR: KPOF 091753Z AUTO 22018G30KT 10SM CLR 19/06 A3032 RMK AO2 PK WND 21030/1744 SLP269 T01890061 10189 20033 58018 ## 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 20210309005649A](https://openairdocs.org/incident/20210309005649A), Mar 9, 2021: Cessna 170A, Wilby, MO, Substantial damage. Pilot was unable to locate his intended landing airport at poplar bluff, MO. And became low on fuel after searching for the airport. He felt he had… ## Docket (6 files) The files NTSB released with the investigation on July 26, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102750. 1.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 409 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770760&FileExtension=pdf&FileName=01%20-%20Pilot%20Report_Redacted-Rel.pdf - Memorandum of conversation (richard w ryan) (item 2, PDF, 5 pages, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770825&FileExtension=pdf&FileName=02%20-%20Memorandum%20of%20Conversation%20(Richard%20W%20Ryan)-Rel.pdf - FAA inspector statement (dennis j mueller) (item 3, PDF, 2 pages, 61 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770671&FileExtension=pdf&FileName=03%20-%20FAA%20Inspector%20Statement%20(Dennis%20J%20Mueller)_Redacted-Rel.pdf - FAA record of conversation (richard w ryan) (item 4, PDF, 1 page, 43 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770351&FileExtension=pdf&FileName=04%20-%20FAA%20Record%20of%20Conversation%20(Richard%20W%20Ryan)-Rel.pdf - Bench test summary (alternator - voltage regulator - battery) (item 5, PDF, 3 pages, 152 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770608&FileExtension=pdf&FileName=05%20-%20Bench%20Test%20Summary%20(Alternator%20-%20Voltage%20Regulator%20-%20Battery)-Rel.pdf - Photos (item 6, PDF, 4 pages, 4 photos, 656 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15770835&FileExtension=pdf&FileName=06%20-%20Photos-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.