# NTSB CEN11FA202: Cessna T210M, N6149B, Independence, MO, February 24, 2011

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Field investigation · Final report
- Date: February 24, 2011, 01:45 local (07:45 UTC)
- Place: Independence, MO
- Coordinates: 39.094444, -94.435279 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.0944&lon=-94.4353&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Defining event: [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed, report January 15, 2013
- Report: Approved by Office Director
- NTSB office: Central Region
- Parties: FAA -- Kansas City FSDO, Flight Express, Inc., Continental Motors Inc.
- NTSB case key (mKey): 78422
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11FA202
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78422/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78422
- Page: https://openairdocs.org/ntsb/CEN11FA202

## Probable cause

Latent dimensional discrepancies related to the engine crankcase main bearing saddle bores, which precipitated the fatigue failure of the crankshaft and a complete loss of engine power. Contributing to the accident was the engine manufacturer's failure to properly identify and address the crankcase discrepancies when the engine was rebuilt.

## Findings

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

- [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Inadequate inspection (probable cause); cases with it: [Cessna T210M, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073451), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md)
- [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna T210M, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073451), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md)
- [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cessna T210M, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073451), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md)

## Sequence of events

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

- [Enroute: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cessna T210M, 3 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=2073451), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md)
- [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Cessna T210M, 17 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073451), [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: [Cessna T210M, 11 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073451), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md)
- [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna T210M, 18 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073451), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md)

## Analysis

The pilot reported that he was in cruise flight when the engine began to run rough and lose power. Smoke began to enter the cockpit, and engine oil covered the windshield. The engine ultimately lost all power. The pilot executed a forced landing to a roadway, and the left wing struck a bridge guardrail. Examination of the engine revealed a fatigue failure of the crankshaft initiating at the No. 6 connecting rod journal. Further examination determined that several crankcase main bearing saddles were oversized compared to the required specifications. As a result, the crankshaft was not adequately supported within the crankcase during operation, which precipitated the fatigue failure of the crankshaft. Records indicated that the engine was initially manufactured with one oversized saddle bore. The manufacturer subsequently rebuilt the engine, which was installed on the accident airplane. At the time of the accident, the engine had accumulated 1,303.5 hours since it was rebuilt.

## Factual narrative

HISTORY OF FLIGHT On February 24, 2011, about 0145 central standard time, a Cessna T210M, N6149B, was substantially damaged during a forced landing following a loss of engine power in cruise flight near Independence, Missouri. The pilot made a forced landing to a roadway. The airplane was registered to and operated by Flight Express Inc. under the provisions of 14 Code of Federal Regulations Part 135 as an on-demand cargo flight. Night visual meteorological conditions prevailed and no flight plan was filed. The pilot sustained minor injuries. The flight originated from St. Louis Downtown Airport, Cahokia, Illinois, about 0030. The intended destination was Charles B. Wheeler Downtown Airport (MKC), Kansas City, Missouri. The pilot reported that he was in cruise flight at 4,000 feet mean sea level, about 18 miles from the intended destination, when the engine began to run rough and lose power. Smoke began to enter the cockpit and engine oil covered the windshield. The engine ultimately lost all power. The pilot executed a forced landing to a roadway. The left wing struck a roadway bridge guard railing during the landing. PERSONNEL INFORMATION The pilot held an airline transport pilot certificate with single and multi-engine land airplane ratings. He also held a flight instructor certificate with single and multi-engine airplane and instrument airplane ratings. He was issued a first class airman medical certificate on March 1, 2010. The pilot reported that at the time of the accident, he had accumulated about 5,800 hours total flight time, with approximately 900 hours in Cessna 210 airplanes. His most recent flight review was completed on December 4, 2010. AIRCRAFT INFORMATION The accident airplane was a 1978 Cessna T210M, serial number 21062694. It was configured with one pilot seat to facilitate cargo operations. The airplane was powered by a 300-horsepower Continental Motors IO-550-P8B engine, serial number 821115-R. The operator reported a total airframe time of 12,103.0 hours at the time of the accident, with 88.3 hours since the most recent inspection. The engine had accumulated 1,303.5 hours at the time of the accident. The most recent inspection was completed on January 3, 2011, at 12,014.7 hours total airframe time. An engine oil change was completed on January 31, 2011. Maintenance records indicated that the engine was rebuilt by Continental Motors and installed on the accident airplane in March 2009. METEOROLOGICAL INFORMATION Weather conditions recorded at the Charles B. Wheeler Downtown Airport (MKC), located about 14 miles west of the accident site, at 0154, were: wind from 030 degrees at 7 knots; 10 miles visibility; overcast clouds at 6,000 feet above ground level; temperature 5 degrees Celsius; dew point 1 degree Celsius; altimeter 30.01 inches of mercury. Weather conditions recorded at the Lee’s Summit Municipal Airport (LXT), located about 10 miles south-southwest of the accident site, at 0153, were: wind from 040 degrees at 7knots; 10 miles visibility; overcast clouds at 5,000 feet above ground level; temperature 4 degrees Celsius; dew point 2 degrees Celsius; altimeter 30.01 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane came to rest on a roadway after the forced landing. The left wing struck a guard railing, resulting in substantial damage. Specifically, the lower left wing skin was cut across approximately the entire chord of the wing. Two of the impact cuts were located near the wingtip; the third was near mid-span outboard of the pitot tube. The contact with the guard rail also caused associated damage to the wing substructure in the area of the wing skin damage. TESTS AND RESEARCH A teardown engine examination was conducted under the direct oversight of the NTSB. The crankcase exhibited an approximate 4 inch by 8 inch opening forward of the No. 5 cylinder bore and extending above the No. 6 cylinder bore. The crankshaft was fractured between the No. 6 connecting rod journal and the No. 4 crankshaft main journal. The No.4 main bearing was observed to be shifted within the crankcase saddle. The No. 3 main bearing was fractured into multiple pieces, most of which were recovered from the oil sump. The camshaft was fractured at two locations; between the No. 6 intake and exhaust lobes, and common to the No. 3 main journal. The No. 6 connecting rod bolts were fractured. The No. 6 connecting rod was deformed and exhibited gouges consistent with secondary mechanical damage. The No. 5 and No. 6 pistons exhibited damage consistent with secondary mechanical impact. Specifically, portions of the skirt areas on both pistons were separated from the remainder of the associated piston. Piston fragments were recovered from the oil sump. This damage was also consistent with secondary mechanical impact. The crankshaft fracture surfaces exhibited features consistent with fatigue initiating at the forward radius of the No. 6 connecting rod journal. Three additional cracks were also observed initiating at the forward flank of the No. 3 main journal, the forward flank of the No. 4 connecting rod journal, and the aft flank of the No. 5 connecting rod journal. The camshaft fracture surface features were consistent with fatigue caused by reverse bending. Failure of the No. 6 connecting rod bolts was consistent with overstress. Records indicated that the No. 3 crankcase main saddle bearing diameter was oversize by 0.0017 inch when it was originally manufactured. The crankcase was subsequently reconditioned by the manufacturer for use in the rebuilt engine. The manufacturer’s engineering documentation related to reconditioned crankcase saddle bores noted that the diameter may exceed the specified limit by 0.002 inch within a 40-degree arc centered on the splint line of the crankcase. Outside of that area the diameter must conform to the dimensional requirements. Measurements of the crankcase saddle bores revealed oversize diameters at multiple locations. At a pointoriented 90 degrees to the crankcase split line, all saddle bore diameters measured within specifications. At saddle bores No. 1, No. 4, and No. 5, one of the diameter measurements taken at either the plus or minus 20-degree limit from the split line was oversized. At the No. 2 and No. 3 saddle bores, the diameter was oversized at both the plus and minus 20-degree limit. The maximum dimension, located on the No. 3 bore diameter, measured 2.8185 inch and was 0.0015 inch over the dimensional limit.

## Aircraft

- Registration: [N6149B](https://openairdocs.org/deregistered/N6149B-2015-01-30), registration cancelled 2015-01-30, S/N 21062694 (OpenAirDocs)
- Reported make and model: CESSNA T210M
- Registry model: [Cessna T210M](https://openairdocs.org/model/cessna-t210m) (registry code 2073451) (OpenAirDocs)
- Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 21062694
- Airframe hours: 12103
- Engines: CONT MOTOR IO-550-P8B 300 horsepower reciprocating
- Damage: Substantial damage
- Flight: Part 135
- Operator: Flight Express Inc.
- Registered owner: Flight Express Inc.
- Airworthiness certificate: Standard, Normal; Standard, Utility
- Last inspection: 100 hour, January 4, 2011, 88 hours before
- Departed: CPS, Cahokia, IL
- Destination: MKC, Kansas City, MO
- Flight plan: Company VFR
- Airport: MKC, Charles B. Wheeler Downtown

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; injuries: minor; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 4, 2010; seat: left; flight hours: 5,800 total, 900 in this make and model, 5,670 as pilot in command, 150 in the last 90 days, 80 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night
- Wind: 40° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: 5,000 ft overcast
- Temperature: 39 °F, dew point 36 °F
- Altimeter: 30.01 inHg
- Observed at: LXT, 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 20110224002289A](https://openairdocs.org/incident/20110224002289A), Feb 24, 2011: Cessna T210M, Independence, MO, Substantial damage. Aircraft departed cps at approximately 0020 enroute to mkc. Approximately 18 NM out of mkc, pilot felt a shudder and lost about 80% of engine power. Pilot…

## Docket (6 files)

The files NTSB released with the investigation on November 2, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78422. 10.2 MB in all.

- Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 850 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377995&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF
- Airframe Maintenance Records -- Excerpts (item 2, .PDF, 146 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378474&FileExtension=.PDF&FileName=Airframe%20Maintenance%20Records%20--%20Excerpts-Redacted.PDF
- Engine Maintenance Records -- Excerpts (item 3, .PDF, 699 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378653&FileExtension=.PDF&FileName=Engine%20Maintenance%20Records%20--%20Excerpts-Redacted.PDF
- Engine Examination Report (item 4, .PDF, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378657&FileExtension=.PDF&FileName=Engine%20Examination%20Report-Redacted.PDF
- Materials Laboratory 15 - Factual Report 11-135 (with 33 embedded photos) (item 5, .PDF, 4.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40376034&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%2011-135%20(with%2033%20embedded%20photos)-Master.PDF
- Statement of Party Representatives to NTSB Investigation (item 6, .PDF, 397 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378658&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.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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