# NTSB ANC20CA030: Piper PA18, N7384D, Big Lake, AK, February 29, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: February 28, 2020, 16:40 local (Feb 29, 2020, 01:40 UTC) - Place: Big Lake, AK - Coordinates: 61.534721, -149.798889 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.5347&lon=-149.7989&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 29, 2020 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA - NTSB case key (mKey): 101058 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC20CA030 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101058/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101058 - Page: https://openairdocs.org/ntsb/ANC20CA030 ## Probable cause The pilot's failure to use carburetor heat in conditions conducive to carburetor icing, which resulted in a partial loss of engine power, a precautionary landing, and impact with snow. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-18-150, 4 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=7101828), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-18-150, 20 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7101828), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Ice/rain protection system: intake anti-ice, deice](https://openairdocs.org/ntsb-findings/01023020): Aircraft › Aircraft systems · Not used/operated (probable cause); cases with it: [Piper PA-18-150, 4 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md?model=7101828), [All aircraft, 108 cases](https://openairdocs.org/ntsb-findings/01023020/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [Piper PA-18-150, 15 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=7101828), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Other weather encounter](https://openairdocs.org/ntsb-events/400); cases with it: [Piper PA-18-150, 26 cases](https://openairdocs.org/ntsb-events/400/sequence.md?model=7101828), [All aircraft, 1,127 cases](https://openairdocs.org/ntsb-events/400/sequence.md) - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Piper PA-18-150, 13 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=7101828), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Initial climb: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Piper PA-18-150, 18 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7101828), [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: [Piper PA-18-150, 15 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7101828), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Piper PA-18-150, 35 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=7101828), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-18-150, 115 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7101828), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Piper PA-18-150, 83 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7101828), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, while performing touch-and-go landings, he applied carburetor heat during the second landing. During takeoff after the second landing, he turned the carburetor heat off and applied full power. Once airborne, the airplane began to lose power, and he manipulated the throttle and carburetor heat levers, but engine power was not restored. He chose to make a precautionary landing straight-ahead on the runway with partial engine power. During the landing, the airplane departed the end of the runway, impacted snow, and nosed over. The airplane sustained substantial damage to the right-wing lift strut and empennage. A postaccident engine examination and test run revealed no preaccident malfunctions or failures with the airplane that would have precluded normal operation. The exact probability of carburetor icing could not be calculated for the accident airport because the closest weather observation station was 8 miles away. However, the pilot stated that, while landing, there were about 3 inches of fresh snow on the runway and that he believed that propeller wash likely introduced snow into the intake, which created carburetor ice. He added that he should have left the carburetor heat on longer after the second landing. ## Factual narrative The pilot reported that while performing touch-and-go maneuvers, he had applied carburetor heat during the second landing. During the takeoff, after the second landing, he turned the carburetor heat off and applied full power. Once airborne, the airplane began to lose power and he manipulated the throttle and carburetor heat levers but was unable to regain power. He chose to make a precautionary landing straight-ahead with partial engine power. During the landing on the remaining runway, the airplane departed the end of the runway, encountered unmaintained snow, and nosed over. The airplane sustained substantial damage to the right wing lift strut and empennage. A post-accident engine examination and test run was accomplished by the NTSB and FAA with no malfunctions or failures revealed. The exact probability of carburetor icing was not able to be calculated for the accident airport due to the closest weather observation station being 8 miles away. The pilot however stated that while landing, there was about 3 inches of fresh snow on the runway, and that he believed the propeller wash likely introduced snow into the intake, which created carburetor ice. He added that he should have left the carburetor heat on longer after the second landing. ## Aircraft - Registration: [N7384D](https://openairdocs.org/aircraft/N7384D), registered now, S/N 18-5749 (OpenAirDocs) - Reported make and model: Piper PA18 (150) - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-5749 - Year built: 1957 - Airframe hours: 3382.2 - Engines: Lycoming O-320-E2D 150 hp reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 22, 2020 - Departed: 4AK6, Palmer, AK - Destination: BGQ, Big Lake, AK - Airport: BGQ, Big Lake, runway 7, 2,450 × 70 ft, snow - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; airline transport, commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review August 5, 2019; seat: front; restraint: 3-point; flight hours: 11,104 total, 570 in this make and model, 5,783 as pilot in command, 120 in the last 90 days, 39 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 23 °F, dew point 9 °F - Altimeter: 29.95 inHg - Observed at: PAWS, 8 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 20200228004099A](https://openairdocs.org/incident/20200228004099A), Feb 28, 2020: Piper PA-18-150, Big Lake, AK, Substantial damage. Pilot states that he departed wolf lake and flew to Big Lake to perform touch and go maneuvers. Pilot had carb heat turned on during the second landing and… ## Other investigations on N7384D (1) 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. - [NTSB ANC67D0045](https://openairdocs.org/ntsb/ANC67D0045), Sep 15, 1966: Piper PA-18 (N7384D), Big Delta, AK, substantial damage ## Docket (3 files) The files NTSB released with the investigation on April 21, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101058. 1.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 415 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482781&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Engine Exam (item 2, .PDF, 805 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482782&FileExtension=.PDF&FileName=Engine%20Exam-Master.PDF - Accident Pictures (item 3, .PDF, 172 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482783&FileExtension=.PDF&FileName=Accident%20Pictures-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.