# NTSB ANC20LA002: Cessna 172, N7267A, Palmer, AK, October 13, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: October 12, 2019, 16:20 local (Oct 13, 2019, 00:20 UTC) - Place: Palmer, AK - Coordinates: 61.450279, -148.683334 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.4503&lon=-148.6833&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 100431 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC20LA002 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100431/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100431 - Page: https://openairdocs.org/ntsb/ANC20LA002 ## Probable cause The pilot's delayed application of carburetor heat in weather conditions conducive to carburetor icing, which resulted in a partial loss of engine power, a precautionary landing, and impact with terrain. ## 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: [Cessna 172, 7 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=2072402), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [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: [Cessna 172, 4 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=2072402), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) - [Action: delayed action](https://openairdocs.org/ntsb-findings/02041025): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 172, 8 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md?model=2072402), [All aircraft, 894 cases](https://openairdocs.org/ntsb-findings/02041025/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 172, 4 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=2072402), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Object/animal/substance: tree(s)](https://openairdocs.org/ntsb-findings/03022020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna 172, 8 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md?model=2072402), [All aircraft, 933 cases](https://openairdocs.org/ntsb-findings/03022020/cases.md) - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [Cessna 172, 2 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=2072402), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Cessna 172, 3 cases](https://openairdocs.org/ntsb-events/190/sequence.md?model=2072402), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Cessna 172, 4 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072402), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Enroute: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Cessna 172, 3 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=2072402), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 172, 10 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072402), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Cessna 172, 8 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=2072402), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 172, 11 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072402), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, about 15 minutes after departure, the engine began to run rough and experienced a partial loss of power. He provided conflicting statements about the phase of flight when this occurred; he was either in cruise flight or was flying at a reduced power setting during a low approach to a remote site. After completing emergency engine procedures, which included applying carburetor heat, the pilot was unable to restore engine power and selected an all-terrain vehicle trail as a forced landing site. Just before touchdown, when the airplane was about 15 ft above the ground, the left wing struck a tree, and the airplane yawed left and touched down in a nose-low, off-center angle. The airplane sustained substantial damage to both wings and the fuselage. Postaccident examination of the engine, including a test run, revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. Weather conditions about 15 nautical miles from the accident site were conducive for carburetor icing at cruise power and serious icing at glide power. The pilot only reported applying carburetor heat to restore engine power. Therefore, it is likely that carburetor ice accumulated before he applied the heat, which resulted in a partial loss of engine power. Further, the delayed application of carburetor heat was insufficient to melt the ice and restore power. ## Factual narrative On October 13, 2019, about 1620 Alaska daylight time, a Cessna 172 airplane, N7267A, sustained substantial damage when it was involved in an accident about 15 nautical miles southeast of the Palmer Municipal Airport (PAAQ) Palmer, Alaska. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, after departing the off-airport airstrip near the Knik Glacier, he made a low approach to the same airstrip before continuing the flight to Birchwood Airport (PABV) Birchwood, Alaska. About 15 minutes later, while in cruise flight, the engine began to run rough and the rpm "rolled back." In an attempt to restore engine power, he applied carburetor heat, confirmed a rich mixture, checked the fuel tank levels, and placed the fuel selector from BOTH to the LEFT tank. In addition, he verified the oil pressure, confirmed the magneto switch was selected to BOTH, and that the primer was in and locked. The pilot subsequently selected an all-terrain vehicle trail as a forced landing site. Just before touchdown, about 15 feet above the ground, the left wing struck a small tree and the airplane yawed to the left and touched down in a nose low, off-center angle. Subsequently, the right main landing gear and nose-gear separated, and the right wing struck the ground; the pilot was able to egress the airplane without further incident. The airplane sustained substantial damage to both wings and the fuselage. A post-accident examination of the engine, which included a test run, revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. According to a carburetor icing probability chart, using the nearest weather observation station located about 15 nautical miles away, an airplane operating in the ambient conditions near the accident site would expect carburetor icing at cruise power, and serious icing at glide power. ## Aircraft - Registration: [N7267A](https://openairdocs.org/deregistered/N7267A-2020-07-10), registration cancelled 2020-07-10, S/N 29367, built 1956 (OpenAirDocs) - Reported make and model: Cessna 172 (Undesignat) - Registry model: [Cessna 172](https://openairdocs.org/model/cessna-172) (registry code 2072402) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 29367 - Year built: 1956 - Airframe hours: 2818.85 - Engines: Continental O-300-B 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 5, 2019 - Departed: 4AK6, Palmer, AK - Destination: BCV, Birchwood, AK - Equipment: Handheld GPS, Electronic flight bag or handheld device, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review May 15, 2018; seat: left; restraint: 4-point; flight hours: 190 total, 144 in this make and model, 125 as pilot in command, 26 in the last 90 days, 11 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 41 °F, dew point 27 °F - Altimeter: 29.96 inHg - Observed at: PAAQ, 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 20191013022809A](https://openairdocs.org/incident/20191013022809A), Oct 13, 2019: Cessna 172, Palmer, AK, Substantial damage. On October 13, 2019, about 1620 Alaska daylight time, a Cessna 172 airplane, N7267A, Sustained substantial damage following a collision with terrain during an… ## Docket (3 files) The files NTSB released with the investigation on October 9, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100431. 1.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9788898&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Engine run roc (item 2, PDF, 1 page, 141 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9789492&FileExtension=pdf&FileName=Engine%20Run%20ROC-Rel.pdf - Accident picture (item 3, PDF, 1 page, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9789119&FileExtension=pdf&FileName=Accident%20Picture-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.