# NTSB CEN22LA330: Beech N35, N1228Z, Wardsville, MO, July 20, 2022

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Limited · Final report
- Date: July 20, 2022, 18:45 local (23:45 UTC)
- Place: Wardsville, MO · field
- Coordinates: 38.4964, -92.1943 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.4964&lon=-92.1943&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Defining event: [Approach: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 3
- NTSB office: Central Region
- Parties: Superior Air Parts, Pinnacle Aircraft Engines, FAA Flight Standards
- ADs cited in the narratives: [AD 2022-04-04](https://openairdocs.org/ad/2022-04-04) (OpenAirDocs)
- NTSB case key (mKey): 105542
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA330
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105542/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105542
- Page: https://openairdocs.org/ntsb/CEN22LA330

## Probable cause

Engine failure due to oil starvation resulting from an oil leak at the improperly installed aftermarket oil filter adapter.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Beech N35, 2 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=1151528), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md)
- [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Beech N35, 2 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=1151528), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md)
- [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Beech N35, 2 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=1151528), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md)
- [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Unknown/Not determined (probable cause); cases with it: [Beech N35, 2 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=1151528), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Approach: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Beech N35, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=1151528), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md)
- [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Beech N35, 4 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=1151528), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)

## Analysis

The pilot reported the flight was uneventful until he was approaching the destination airport. During the approach, he observed the oil pressure drop to zero and, shortly afterward, the engine started running rough. The pilot subsequently heard a “bang” from the engine and observed smoke from under the engine cowling. The engine lost power completely and he executed a forced landing to a field. The airframe sustained substantial damage to the forward fuselage. Postaccident examination revealed that the engine failed because of oil starvation. At the time of the examination, the aftermarket oil filter adapter was loose and not safety wired in accordance with the manufacturer’s instructions and the Federal Aviation Administration (FAA) airworthiness directive.

## Factual narrative

On July 20, 2022, about 1845 central daylight time, a Beech N35 airplane, N1228Z, was substantially damaged when it was involved in an accident near Wardsville, Missouri. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. The pilot reported that the departure, climb, and cruise portions of the flight were without incident. During the approach into the intended destination airport, he observed the oil pressure drop to zero and, shortly afterward, the engine started running rough. The pilot subsequently heard a “bang” from the engine and observed smoke from under the engine cowling. The engine lost power completely and he executed a forced landing to a field. The airframe sustained damage to the forward fuselage. An engine examination revealed that the Nos. 1 and 4 cylinder connecting rods, connecting rod caps, and bolts had failed at the crankshaft journal. In addition, the No. 5 connecting rod was discolored at the crankshaft consistent with overheating due to oil starvation. The upper portion of the crankcase above the No. 4 cylinder exhibited a 3 inch by 3 inch hole. Connecting rod cap and retaining bolt fragments were recovered from the crankcase and oil sump, along with about one quart of oil. At the time of the examination, the aftermarket oil filter adapter was loose and could be rotated about 40° using only finger-tip pressure. One safety wire was installed directly from the adapter spool to the oil pump housing and without any significant tension. There was no safety wire installed between the adapter sleeve and the engine. According to the airplane’s maintenance records, the engine was overhauled in March 2021 and installed on August 7, 2021, at an airframe time of 7,329 hours. A representative of the overhaul facility reported the oil filter adapter was furnished installed with the overhauled engine. The maintenance records noted that, on February 19, 2022, at 7,379 hours airframe time, the oil filter adapter was removed and reinstalled using new copper gaskets due to an oil leak. The mechanic confirmed that a torque wrench was used when reinstalling the adapter. On June 21, 2022, at 7,405 hours airframe time, the engine oil was replaced by the pilot/owner. According to the pilot/owner, the oil filter was not replaced at that time. In addition, he stated the alignment marks between the adapter and the engine were still matched up. At the time of the accident, the airframe time was 7,420 hours. On February 21, 2020, the oil filter adapter manufacturer issued updated installation instructions (DN ST002 Rev 1) that implemented the use of copper gaskets, replacing the original fiber gaskets. The instructions required the use of a torque wrench to 65-ft lbs and installation of safety wire from the adapter spool to the engine, and from the adapter sleeve to the engine. On June 17, 2021, the oil filter adapter manufacturer revised a previously issued mandatory servicebulletin (SB-001 Rev B) regarding the oil filter adapter installation. The bulletin specified removal of any fiber gaskets still in service and the use of copper gaskets due to reports of oil leaks. The adapter installation was to be inspected for security and proper safety wire installation at each oil change, each 100-hour/annual inspection, and any time the adapter was removed or installed. The bulletin reiterated that safety wire be installed from the adapter spool to the engine, and from the adapter sleeve to the engine. FAA Airworthiness Directive (AD) 2022-04-04 became effective on March 29, 2022. The AD mandated replacement of the fiber gaskets with copper gaskets and the reinstallation of the adapter, as noted in the corresponding service bulletin, within 50 flight hours or at the next oil change, whichever occurred first. The oil filter adapter was equipped with copper gaskets at the time of the accident. On June 16, 2022, the adapter manufacturer revised the service bulletin (SB-001 Rev C) to specify an improved gasket to be used in place of the lower copper gasket. It also specified an inspection of the adapter installation within 10 flight hours or at the next annual/100-hour inspection, whichever occurred first. Service bulletins are not regulatory in nature and compliance is not required for aircraft operated under 14 CFR Part 91. Airworthiness directives are regulatory in nature and compliance is required as specified in the directive.

## Aircraft

- Registration: [N1228Z](https://openairdocs.org/aircraft/N1228Z), registered now, S/N D-6688, built 1961 (OpenAirDocs)
- Reported make and model: BEECH N35
- Registry model: [Beech N35](https://openairdocs.org/model/beech-n35) (registry code 1151528) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: D-6688
- Year built: 1961
- Airframe hours: 7420
- Engines: CONT MOTOR IO-470-N 260 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 20, 2021, 91 hours before
- Departed: 0TE4, Hilltop Lakes, TX
- Destination: JEF, Jefferson City, MO
- Equipment: Satellite tracking device, Stall warning system, ADS-B, Electronic flight bag or handheld device, Electronic primary flight display, Handheld GPS

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 78; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review November 30, 2021; seat: left; restraint: lap only; flight hours: 6,578 total, 3,721 in this make and model, 6,447 as pilot in command, 36 in the last 90 days, 22 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 91 °F, dew point 63 °F
- Altimeter: 29.79 inHg
- Observed at: KJEF, 6 nm away
- METAR: METAR KJEF 202353Z 31008KT 10SM CLR 33/17 A2979

## 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 20220720013319A](https://openairdocs.org/incident/20220720013319A), Jul 20, 2022: Beech N35, Wardsville, MO, Substantial damage. The pilot was in cruise flight enroute to oshkosh, WI when he lost power and started to see smoke coming from the engine cowling. He executed a forced landing…

## Docket (15 files)

The files NTSB released with the investigation on November 15, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105542. 184 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 26.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14743722&FileExtension=pdf&FileName=Accident%20Report%20--%20CEN22LA330_redacted-Rel.pdf
- Accident photos (item 2, PDF, 10 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990725&FileExtension=pdf&FileName=02_Accident%20Photos%20--%20CEN22LA330-Rel.pdf
- Examination summary (item 3, PDF, 5 pages, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990219&FileExtension=pdf&FileName=03_Examination%20Summary%20--%20CEN22LA330-Rel.pdf
- Maintenance records -- airframe (item 4, PDF, 8 pages, 119 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990452&FileExtension=pdf&FileName=04_Maintenance%20Records%20--%20Airframe_redacted-Rel.pdf
- Maintenance records -- engine (item 5, PDF, 7 pages, 30.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14989034&FileExtension=pdf&FileName=05_Maintenance%20Records%20--%20Engine_redacted-Rel.pdf
- Conversation summary -- mechanic (item 6, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15109459&FileExtension=pdf&FileName=ROC%20--%20Lee%20Allen%20--%2017Nov2022-Rel.pdf
- Conversation summary -- pilot/owner (item 7, PDF, 1 page, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15120823&FileExtension=pdf&FileName=ROC%20--%20Ron%20Pate%20--%2021Feb2023-Rel.pdf
- Oil filter adapter installation instructions -- rev 1 (item 8, PDF, 8 pages, 697 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15109216&FileExtension=pdf&FileName=Installation%20Instructions%20--%20C6LC-L%20Rev1-Rel.pdf
- Oil filter adapter installation instructions -- rev 2 (item 9, PDF, 9 pages, 775 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15107699&FileExtension=pdf&FileName=Installation%20Instructions%20--%20C6LC-L%20Rev2-Rel.pdf
- Instructions for continued airworthiness -- oil filter adapter (item 10, PDF, 6 pages, 558 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990462&FileExtension=pdf&FileName=08_Instructions%20for%20Continued%20Airworthiness%20--%20Oil%20Filter%20Adapter%20--%20Stratus%20Tool%20Technologies-Rel.pdf
- Service bulletin -- stratus-SB-001_rev-b (item 11, PDF, 11 pages, 923 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990664&FileExtension=pdf&FileName=06_Service%20Bulletin%20--%20Stratus-SB-001_Rev-B-Rel.pdf
- Service bulletin -- stratus-SB-001_rev-c (item 12, PDF, 11 pages, 910 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14989044&FileExtension=pdf&FileName=07_Service%20Bulletin%20--%20Stratus-SB-001_Rev-C-Rel.pdf
- FAA airworthiness directive 2022-04-04 (item 13, PDF, 7 pages, 512 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14990382&FileExtension=pdf&FileName=09_FAA%20Airworthiness%20Directive%202022-04-04-Rel.pdf
- FAA safety alert -- safo 21001 / oil filter adapter installation and maintenance (item 14, PDF, 3 pages, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15115306&FileExtension=pdf&FileName=FAA%20SAFO21001%20(Oil%20Filter%20Adapter%20Install)-Rel.pdf
- Statement of party representatives to NTSB investigation (item 15, PDF, 2 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14744055&FileExtension=pdf&FileName=Party%20Stmts%20--%20CEN22LA330_redacted-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.