# NTSB ERA13LA268: Maule M-4-220C, N40337, Fredericksburg, PA, June 1, 2013

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 1, 2013, 08:30 local (12:30 UTC)
- Place: Fredericksburg, PA
- Coordinates: 40.442779, -76.44139 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.4428&lon=-76.4414&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed, report August 25, 2015
- Report: Approved by Office Director
- NTSB office: Eastern Region Aviation
- Parties: FAA/FSDO
- NTSB case key (mKey): 87094
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA13LA268
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/87094/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=87094
- Page: https://openairdocs.org/ntsb/ERA13LA268

## Probable cause

A total loss of engine power due to the fatigue failure of the No. 4 cylinder piston pin.

## 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 · Fatigue/wear/corrosion (probable cause); cases with it: [Maule M-4-220C, 1 case](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=5460114), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md)
- [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Not serviced/maintained; cases with it: [Maule M-4-220C, 2 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=5460114), [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/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 (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Maule M-4-220C, 5 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=5460114), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md)
- [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Maule M-4-220C, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=5460114), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Maule M-4-220C, 1 case](https://openairdocs.org/ntsb-events/096/sequence.md?model=5460114), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md)

## Analysis

The pilot reported that, while the airplane was in cruise flight, the engine began to vibrate and lose power. The pilot shut down the engine and performed a forced landing to a field. During the landing roll, the airplane nosed over and was substantially damaged. Examination of the engine revealed that the No. 4 cylinder head was partially separated and that the No. 4 piston pin was fractured. The piston pin fractured due to fatigue that had initiated at the pin's outer diameter, and the fracture corresponded to the location of the pin bearing separation from the connecting rod. The bearing fracture surface was obliterated. It is likely that pin and bearing wear altered the stress distribution and precipitated the failure. A review of maintenance records revealed that the 41-year-old engine had been operated for about 1,400 total hours since new and about 50 flight hours since its most recent annual inspection, which was performed about 1 year before the accident. In addition, the No. 4 cylinder was overhauled about 23 years and 560 flight hours before the accident. It was also removed, reconditioned, and reinstalled about 4 years and 165 flight hours before the accident.

## Factual narrative

On June 1, 2013, about 0830 eastern daylight time, a Maule M-4-220C, N40337, operated by a private individual, was substantially damaged during a forced landing, after it experienced a total loss of engine power shortly after takeoff from Farmers Pride Airport (9N7), Fredericksburg, Pennsylvania. The airline transport pilot sustained minor injuries and a passenger was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the flight destined for Baublitz Commercial Airport (9W8), Brogue, Pennsylvania. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91.The pilot reported that he departed 9N7 and had climbed to an altitude of 2,500 feet mean sea level, when the engine began to vibrate and lose power. In addition, the cabin began to fill with white smoke. The pilot shut-down the engine and performed a forced landing to a soy bean field. During the landing roll, the airplane entered a wheat field and nosed over, which resulted in substantial damage to the fuselage and vertical stabilizer. The airplane was manufactured in 1972 and equipped with a Franklin 6A-350-C1, 220-horsepower engine. Initial examination of the engine by a Federal Aviation Administration inspector revealed that the No. 4 cylinder head was partially separated from the cylinder barrel, the No. 4 cylinder piston was fragmented, and the No. 4 piston pin was fractured. The No.4 cylinder, connecting rod, fractured piston pin, and piston fragment were forwarded to the NTSB Materials Laboratory, Washington, DC, for further examination. Examination of the retained engine components by an NTSB metallurgist revealed that the No. 4 piston pin was circumferentially fractured near its midpoint. The connecting rod was not fractured, but the piston pin bearing in the small end was fractured and damaged. The separation surface of the bearing was completely obliterated. When installed, the piston pin fracture corresponded to the separation location of the piston pin bearing in the connecting rod. Additional examination of the piston pin fracture features with a scanning electron microscope revealed striations consistent with fatigue propagation that initiated at the pin outer diameter. The No. 4 piston fragment which was estimated to comprise about one-third of the piston crown was severely battered. Almost all of the fracture surfaces were obliterated by mechanical damage; however, the few undamaged fracture areas appeared typical of overstress separations. The No. 4 cylinder was fractured through its bore consistent with overstress features on both the aluminum cylinder and steel liner, with no indications of preexisting cracking. According to maintenance records, the airplane and engine had been operated for about 50 hours since its most recent annual inspection, which was performed on June 27, 2012. The engine had been operated for about 1,400 total hours since new. In addition, the No. 4 cylinder wasoverhauled during June 1990, about 560 hours prior to the accident, and was also removed, reconditioned, and reinstalled during April 2009, about 165 hours prior to the accident.

## Aircraft

- Registration: [N40337](https://openairdocs.org/deregistered/N40337-2018-03-23), registration cancelled 2018-03-23, S/N 2112C, built 1972 (OpenAirDocs)
- Reported make and model: MAULE M-4-220C
- Registry model: [Maule M-4-220C](https://openairdocs.org/model/maule-m-4-220c) (registry code 5460114) (OpenAirDocs)
- Registry engine: [Franklin 6A-350SER](https://openairdocs.org/engine/franklin-6a-350ser) (registry code 27023, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 2112C
- Year built: 1972
- Airframe hours: 1638
- Engines: FRANKLIN 6A-350SER 220 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 27, 2012, 47 hours before
- Departed: 9N7, Fredericksburg, PA
- Destination: 9W8, BROGUE, PA
- Airport: 9N7, Farmers Pride, runway 28, 3,410 × 150 ft, grass/turf
- Equipment: Stall warning system

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 36; injuries: minor; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review October 14, 2012; seat: left; restraint: lap only; flight hours: 8,100 total, 250 in this make and model, 6,200 as pilot in command, 150 in the last 90 days, 60 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 66 °F
- Altimeter: 30.03 inHg
- Observed at: MUI, 10 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 20130601008419A](https://openairdocs.org/incident/20130601008419A), Jun 1, 2013: Maule M-4-220C, Fredericksburg, PA, Substantial damage. An ATP rated pilot with 1 passenger departed 9N7 at 0825 local EDT in VMC conditions. Pilot leveled off aircraft at 2500 MSL and began to set cruise power when…

## Docket (10 files)

The files NTSB released with the investigation on July 14, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=87094. 20.1 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429170&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Memorandum Of Record (item 2, .PDF, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429171&FileExtension=.PDF&FileName=Memorandum%20Of%20Record-Master.PDF
- Maintenance Records (excerpts) (item 3, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429172&FileExtension=.PDF&FileName=Maintenance%20Records%20(excerpts)-Redacted.PDF
- Material Laboratory Factual Report – Engine Cylinder and Piston (item 4, .PDF, 3 photos, 636 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429173&FileExtension=.PDF&FileName=Material%20Laboratory%20Factual%20Report%20%E2%80%93%20Engine%20Cylinder%20and%20Piston-Master.PDF
- Material Laboratory Factual Report – Engine Connecting Rod and Piston Pin (item 5, .PDF, 11 photos, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429174&FileExtension=.PDF&FileName=Material%20Laboratory%20Factual%20Report%20%E2%80%93%20Engine%20Connecting%20Rod%20and%20Piston%20Pin-Master.PDF
- Evidence Control Forms (item 6, .PDF, 298 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429176&FileExtension=.PDF&FileName=Evidence%20Control%20Forms-Redacted.PDF
- Photo 1 – Airplane as it came to rest (Provided by FAA) (item 7, .PDF, 2.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429177&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Airplane%20as%20it%20came%20to%20rest%20(Provided%20by%20FAA)-Master.PDF
- Photo 2 – Top View of No. 4 Cylinder (Provided by FAA) (item 8, .PDF, 3.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429178&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93%20Top%20View%20of%20No.%204%20Cylinder%20(Provided%20by%20FAA)-Master.PDF
- Photo 3 – Internal View of No. 4 Cylinder Head (Provided by FAA) (item 9, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429179&FileExtension=.PDF&FileName=Photo%203%20%E2%80%93%20Internal%20View%20of%20No.%204%20Cylinder%20Head%20%20%20(Provided%20by%20FAA)-Master.PDF
- Photo 4 – Internal View of No. 4 Cylinder Barrel(Provided by FAA) (item 10, .PDF, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40429180&FileExtension=.PDF&FileName=Photo%204%20%E2%80%93%20Internal%20View%20of%20No.%204%20Cylinder%20Barrel(Provided%20by%20FAA)-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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