# NTSB ERA19LA008: North American Navion A, N969TR, Stonewall, MS, October 5, 2018

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 5, 2018, 14:45 local (19:45 UTC)
- Place: Stonewall, MS
- Coordinates: 32.131668, -88.793334 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.1317&lon=-88.7933&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report August 10, 2020
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- Parties: Continental Motors, FAA/FSDO
- NTSB case key (mKey): 98454
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA19LA008
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98454/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98454
- Page: https://openairdocs.org/ntsb/ERA19LA008

## Probable cause

The fatigue failure of the No. 3 cylinder exhaust valve, which resulted in a fractured camshaft and a total loss of engine power.

## Findings

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

- [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [North American NAVION A, 1 case](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=6150132), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md)
- [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [North American NAVION A, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=6150132), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md)
- [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [North American NAVION A, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=6150132), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md)

## Sequence of events

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

- [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [North American NAVION A, 3 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=6150132), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [North American NAVION A, 1 case](https://openairdocs.org/ntsb-events/092/sequence.md?model=6150132), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md)

## Analysis

The pilot stated that, while en route to his destination, the airplane's engine sputtered and then lost total power. During the subsequent forced landing to a highway, the airplane landed hard, and the landing gear collapsed; the airplane sustained substantial damage to the fuselage. A postaccident examination of the engine revealed the No. 3 cylinder exhaust valve fractured where the stem transitioned to the valve head seat. The valve head impacted the No. 3 piston and became lodged between the crankcase and the camshaft, which resulted in the fracture of the camshaft. Fatigue cracking, which initiated at multiple sites, propagated through the valve stem. The presence of a tapered stem near the fracture surface, high temperature oxide deposits, and fatigue striations on the fracture surface suggested that the stem underwent spallation or erosion of the oxides formed during high temperature exposure, which would reduce the stem cross-section over time, increasing the likelihood of initiating fatigue cracking. Additionally, a localized area of wear on the top face of the valve stem was most likely due to the valve not rotating during operation, which could create hot spots or improper thermal dissipation in the hottest parts of the valve and lead to valve damage or failure.

## Factual narrative

On October 5, 2018, about 1445 central daylight time, a North American Navion A, N969TR, was substantially damaged during a forced landing near Stonewall, Mississippi. The private pilot was not injured. The airplane was registered to the pilot and was being operated as Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the flight that departed Key Field Airport (MEI), Meridian, Mississippi, at 1438, and was destined for Jack Edwards National Airport (JKA), Gulf Shores, Alabama.The pilot stated that he was flying at 3,500 ft when the engine sputtered. He informed air traffic control that he wanted to return to MEI and turned back toward the airport, but the engine stopped producing power. The pilot realized that he was not going to be able to reach MEI or any other airport and made a forced landing to a highway. The pilot said he bled off airspeed to avoid hitting cars and landed hard. The airplane's landing gear collapsed, and the airplane slid about 200 ft and came to rest upright on the road, which resulted in substantial damage to the fuselage. A postaccident examination of the engine revealed the No. 3 cylinder exhaust valve fractured where the stem transitioned to the valve head. The valve head was found lodged between the crankcase and the camshaft, and the camshaft was fractured between the No. 3 intake and exhaust lobes. Metallurgical examination of the liberated valve head and the valve stem revealed that the valve head was damaged from repeated contact with the piston and the valve stem exhibited fracture surfaces consistent with fatigue. The fatigue cracking propagated through the valve stem, initiating at multiple crack initiation sites on the stem surface. The valve stem also exhibited tapering near the fracture surface, and surface oxidation and deposits of lead-based compounds which were also present on the exterior of the stem adjacent to the fracture surface. A small depressed area was also noted on the top face of the valve stem, which was consistent with repeated contact with the adjacent rocker. The last annual inspection of the airplane and engine was on August 1, 2018. At the time of the accident, the engine had accrued a total of 1,705.0 hours and 641.5 hours since overhaul. Further review of the engine maintenance logbook revealed that on May 4, 2014, at an engine total time of 1,390.4 hours and 322.1 hours since overhaul, a mechanic "removed and reinstalled all six cylinders with new base seals, push rod tubes seals, intake tube seals, exhaust gaskets and rocker gaskets after resurfacing valves and seats."

## Aircraft

- Registration: [N969TR](https://openairdocs.org/deregistered/N969TR-2021-10-30), registration cancelled 2021-10-30, S/N NAV-4-342, built 1946 (OpenAirDocs)
- Reported make and model: North American NAVION A (No Series)
- Registry model: [North American NAVION A](https://openairdocs.org/model/north-american-navion-a) (registry code 6150132) (OpenAirDocs)
- Registry engine: [Continental E185 series](https://openairdocs.org/engine/continental-e185-series) (registry code 17014, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: NAV-4-342
- Year built: 1946
- Airframe hours: 3336
- Engines: Continental E-225-4 205 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, August 1, 2018, 11 hours before
- Departed: MEI, Meridian, MS
- Destination: JKA, Gulf Shores, AL
- Equipment: Onboard weather, Handheld GPS, Electronic primary flight display, Electronic multifunction display, Satellite tracking device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review April 30, 2017; seat: left; restraint: lap only; flight hours: 568 total, 264 in this make and model, 439.2 as pilot in command, 11 in the last 90 days, 8.3 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: 8,000 ft broken
- Temperature: 91 °F, dew point 68 °F
- Altimeter: 30.02 inHg
- Observed at: MEI, 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 20181005024469A](https://openairdocs.org/incident/20181005024469A), Oct 5, 2018: North American NAVION A, Stonewall, MS, Substantial damage. N969TR departed kmei with the intended destination of kjka. While in cruise, the aircraft suffered an engine failure. Due to the engine failure, the pilot made…

## Docket (8 files)

The files NTSB released with the investigation on June 8, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98454. 25.3 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484180&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF
- Photos (item 2, .PDF, 280 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484181&FileExtension=.PDF&FileName=Photos-Master.PDF
- Continental Engine Teardown Report (item 3, .PDF, 9.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484182&FileExtension=.PDF&FileName=Continental%20Engine%20Teardown%20Report-Master.PDF
- Materials Laboratory Factual Report (item 4, .PDF, 11.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484183&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report-Master.PDF
- Maintenance Records (item 5, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484184&FileExtension=.PDF&FileName=Maintenance%20Records-Master.PDF
- Statement of Party Representatives to NTSB Investigation (item 6, .PDF, 269 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484185&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF
- NTSB Evidence Control Form for Engine (item 7, .PDF, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484186&FileExtension=.PDF&FileName=NTSB%20Evidence%20Control%20Form%20for%20%20Engine-Master.PDF
- NTSB Evidence Control Form for Valve (item 8, .PDF, 112 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484187&FileExtension=.PDF&FileName=NTSB%20Evidence%20Control%20Form%20for%20Valve-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.

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