# NTSB ANC19LA011: Piper PA-22-150, N7640D, Anchorage, AK, January 22, 2019 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: January 22, 2019, 09:15 local (18:15 UTC) - Place: Anchorage, AK - Coordinates: 60.903331, -150.1636 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=60.9033&lon=-150.1636&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: FAA - Juneau Flight Standards District Office - NTSB case key (mKey): 98850 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC19LA011 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98850/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98850 - Page: https://openairdocs.org/ntsb/ANC19LA011 ## Probable cause A loss of engine power due to oil starvation as the result of a loose B-nut fitting on the engine oil cooler, resulting in a forced landing to a soft, snow-covered surface, and a subsequent nose over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Piper PA-22-150, 2 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md?model=7102210), [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md) - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Piper PA-22-150, 1 case](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=7102210), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) - [Eng oil sys (airframe furnish): cooler](https://openairdocs.org/ntsb-findings/01057921): Aircraft › Aircraft power plant · Not serviced/maintained (probable cause); cases with it: [Piper PA-22-150, 1 case](https://openairdocs.org/ntsb-findings/01057921/cases.md?model=7102210), [All aircraft, 7 cases](https://openairdocs.org/ntsb-findings/01057921/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Piper PA-22-150, 7 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=7102210), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342); cases with it: [Piper PA-22-150, 7 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=7102210), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-flare/touchdown: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Piper PA-22-150, 22 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7102210), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that while in level cruise flight he noticed the smell of burning oil, which was immediately followed by a change in engine sound, followed by a partial loss of engine power. The engine continued to lose power and the pilot selected a snow-covered beach as a forced landing site. During touchdown, as the airplane's main landing gear wheels contacted an area of deep snow, it abruptly nosed over, sustaining substantial damage to the wings, fuselage, and empennage. Examination of the engine revealed that there was no engine oil in the sump. An oil cooler B-nut, which was located on the right side of the oil cooler, was found loose, and there was a significant oil streaking on the right side of the fuselage. Review of maintenance records revealed that there had been no recent maintenance activity to the oil cooler or other engine components adjacent to the loose B-nut. Given the accident pilot’s account of the accident, along with the discovery of the loose oil cooler B-nut, it is likely that the engine failed due to oil starvation after all engine oil was lost through the loose B-nut. ## Factual narrative On January 22, 2019, about 0915 Alaska standard time, a Piper PA-22-150 airplane, N7640D, sustained substantial damage when it was involved in an accident near Anchorage, 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 while in level cruise flight over the tidal waters of the Cook Inlet, he noticed the smell of burning oil, which was immediately followed by a change in engine sound. He turned the airplane 180° to return to the southern shoreline of the Cook Inlet, and as the airplane approached the shoreline, the engine began to run rough and lose power. As the airplane passed over the shoreline, the engine continued to lose power and the pilot selected a snow-covered beach as a forced landing site. During touchdown, as the airplane's main landing gear wheels contacted an area of deep snow, it abruptly nosed over, sustaining substantial damage to the wings, fuselage, and empennage. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed a loose oil cooler B-nut located on the right side of the oil cooler. The FAA inspector also reported that there was significant oil streaking on the right side of the fuselage extending from the engine cowling to the empennage. The engine dipstick revealed no engine oil in the sump. A review of the accident airplane’s maintenance records revealed that there was no recent maintenance activity to the oil cooler or other engine components adjacent to the loose B-nut. In a follow-up conversation with the FAA inspector, the pilot noted that during his preflight, just before the accident flight, there were no oil leaks found, and that he routinely checked around the oil cooler during every preflight. ## Aircraft - Registration: [N7640D](https://openairdocs.org/deregistered/N7640D-2023-02-04), registration cancelled 2023-02-04, S/N 22-5349, built 1957 (OpenAirDocs) - Reported make and model: Piper PA-22-150 - Registry model: [Piper PA-22-150](https://openairdocs.org/model/piper-pa-22-150) (registry code 7102210) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 22-5349 - Year built: 1957 - Airframe hours: 2030 - Engines: Lycoming O-320 SERIES 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: J & H Sewing & Vacuum Inc - Registered owner: J & H Sewing & Vacuum Inc - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 14, 2018, 40 hours before - Departed: SXQ, Soldotna, AK - Destination: LHD, Anchorage, AK - Airport: SXQ, Soldotna ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: minor; private; airplane ratings: single-engine land; medical: class 3, unknown; seat: left; restraint: lap only; flight hours: 710 total, 710 in this make and model, 685 as pilot in command, 23 in the last 90 days, 7 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Dawn - Wind: 35° at 15 knots, gusting 20 - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft overcast - Altimeter: 29.92 inHg - Observed at: PANC, 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 20190122000439A](https://openairdocs.org/incident/20190122000439A), Jan 22, 2019: Piper PA-22-150, Anchorage, AK, Substantial damage. Aircraft was in cruise flight headed north over the water of turnagain arm, inbound into Anchorage. Pilot smelled burning oil and engine began "sounding odd".… ## Docket (4 files) The files NTSB released with the investigation on October 5, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98850. 6.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11636736&FileExtension=pdf&FileName=ANC19LA011%206120_Redacted-Rel.pdf - FAA follow-up interviews (item 2, PDF, 1 page, 73 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11636766&FileExtension=pdf&FileName=ANC19LA011%20FAA%20follow%20up%20interviews%20(Dahl)_Redacted-Rel.pdf - FAA wreckage exam report (item 3, PDF, 1 page, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11636863&FileExtension=pdf&FileName=ANC19LA011%20FAA%20Wreckage%20Exam%20Report%20(Varner)_Redacted-Rel.pdf - Photo array (item 4, PDF, 4 pages, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11637390&FileExtension=pdf&FileName=ANC19LA011%20Photo%20Array-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.