# NTSB ANC21LA047: Piper J3C-65, N98109, Sterling, AK, June 28, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: June 28, 2021, 15:30 local (23:30 UTC) - Place: Sterling, AK - Coordinates: 60.716937, -150.33359 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=60.7169&lon=-150.3336&mi=10 - Phase of flight: [Unknown](https://openairdocs.org/ntsb-phases/990) (OpenAirDocs' grouping) - Defining event: [Unknown: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: FAA - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 103376 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC21LA047 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103376/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103376 - Page: https://openairdocs.org/ntsb/ANC21LA047 ## Probable cause A partial loss of engine power for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Piper J3C-65, 7 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=7100510), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Unknown: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Piper J3C-65, 6 cases](https://openairdocs.org/ntsb-events/000/sequence.md?model=7100510), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) ## Analysis The pilot reported that, while en route, the engine lost partial power, and he was unable to restore full power. During the subsequent off-airport landing, the airplane nosed over and came to rest inverted, resulting in substantial damage to the empennage and right wing. A postaccident examination revealed no mechanical failures or malfunctions that would have precluded normal operation. According to the carburetor icing-probability chart located in the Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35, the accident flight would likely have been operating in conditions conducive to “serious icing in cruise power”; however, the pilot reported that he applied carburetor heat following the loss of power. The reason for the loss of power could not be determined based on the available information. ## Factual narrative On June 28, 2021, about 1530 Alaska daylight time, a Piper J3C-65 airplane, N98109, was substantially damaged when it was involved in an accident near Sterling, Alaska. The pilot and one passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he fueled the airplane to capacity 2 days before the accident but had not flown the airplane since. On the day of the accident, he drained “minimal” water from the right-wing fuel tank during his preflight inspection. He added 1 quart of oil to the engine, for a total of 7 quarts. He noted that all the before takeoff checks were normal. While en route, the airplane reached an altitude of about 2,900 ft mean sea level as the pilot planned to cross an ocean channel. The pilot reported that the engine began to “cough, sputter and make popping noises with a loss of power.” He began troubleshooting, including turning the carburetor heat control to ON, and looking for landing sites. He stated that during the descent, the engine would make intermittent power but only for brief periods of time. The pilot notified air traffic control of the emergency and maneuvered the airplane for landing to an area of tundra. During the landing the airplane nosed over and came to rest inverted. The airplane sustained substantial damage to the empennage and right wing. The airframe and engine were examined, and no mechanical failures or malfunctions were observed. The nearest weather observation station, located about 25 miles away, reported a temperature of 59°F and dew point of 46.4°F about the time of the accident. According to the carburetor icing probability chart located in the Federal Aviation Administration Special Airworthiness Information Bulletin CE-09-35, the accident flight would likely have been operating in conditions conducive to “serious icing in cruise power.” ## Aircraft - Registration: [N98109](https://openairdocs.org/aircraft/N98109), registered now, S/N 18268 (OpenAirDocs) - Reported make and model: PIPER J3C-65 - Registry model: [Piper J3C-65](https://openairdocs.org/model/piper-j3c-65) (registry code 7100510) (OpenAirDocs) - Registry engine: [Continental A&C65 series](https://openairdocs.org/engine/continental-a-c65-series) (registry code 17003, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18268 - Year built: 1946 - Airframe hours: 3231 - Engines: Lycoming O-290-D2 135 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 25, 2021 - Departed: HOM, Homer, AK - Destination: LHD, Anchorage, AK - Flight plan: VFR - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; flight instructor, private, commercial, airline transport; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 21, 2021; seat: front; restraint: 3-point; flight hours: 13,990 total, 30 in this make and model, 11,100 as pilot in command, 5 in the last 90 days, 5 in the last 30 days, 1.4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 8 knots - Visibility: 10 statute miles - Temperature: 59 °F, dew point 46 °F - Altimeter: 30.09 inHg - Observed at: PASX, 25 nm away - METAR: PASX 282356Z AUTO 27008KT 10SM SCT065 15/08 A3009 RMK AO2 SLP197 T01500083 10161 20117 56004 ## 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 20210628011079A](https://openairdocs.org/incident/20210628011079A), Jun 28, 2021: Piper J3C-65, Kenai, AK, Substantial damage. On 06/28/2021, N98109, Piper J3, reported engine failure 25 miles north east of Kenai on a VFR flight from hom to lhd. 2 POB, no injuries. Aircraft found… ## Other investigations on N98109 (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 ANC89LA004](https://openairdocs.org/ntsb/ANC89LA004), Oct 3, 1988: Piper J3C-65 (N98109), Eureka Lodge, AK, substantial damage ## Docket (5 files) The files NTSB released with the investigation on October 26, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103376. 6.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12972663&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Owner roc (item 2, PDF, 1 page, 182 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12968031&FileExtension=pdf&FileName=Owner%20ROC-Rel.pdf - FAA notes (item 3, PDF, 2 pages, 89 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12967610&FileExtension=pdf&FileName=FAA%20Notes_Redacted-Rel.pdf - Carburetor icing chart (item 4, PDF, 1 page, 335 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12967735&FileExtension=pdf&FileName=Carburetor%20Icing%20Probability%20Graph%20MJH-Rel.pdf - Accident pictures (item 5, PDF, 3 pages, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12967667&FileExtension=pdf&FileName=Accident%20Pictures-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.