# NTSB CEN09LA447: Cessna A188B, N9747G, Suring, WI, July 16, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 16, 2009, 06:40 local (11:40 UTC) - Place: Suring, WI - Coordinates: 44.884166, -88.458053 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.8842&lon=-88.4581&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 11, 2010 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Milwaukee FSDO, Continental Motors - NTSB case key (mKey): 74325 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN09LA447 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/74325/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=74325 - Page: https://openairdocs.org/ntsb/CEN09LA447 ## Probable cause A loss of engine power resulting from the fatigue failure of the crankshaft due to the loss of engine case through-bolt torque. Contributing to the engine failure was the operator's failure to overhaul the engine in accordance with the manufacturer's recommended guidelines. ## 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 · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna A188B, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073005), [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 A188B, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073005), [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 · Incorrect service/maintenance (probable cause); cases with it: [Cessna A188B, 3 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073005), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Owner/builder (probable cause); cases with it: [Cessna A188B, 5 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2073005), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Owner/builder (probable cause); cases with it: [Cessna A188B, 2 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=2073005), [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. - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna A188B, 8 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073005), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna A188B, 24 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073005), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the engine began to run very rough during a turn at low altitude. The engine suddenly seized so he made an emergency landing to a wheat field. During the landing, the left main gear collapsed and the left wing and nose of the aircraft dug into the soft soil, sustaining substantial damage. A teardown inspection of the engine revealed fretting wear scars on the crankcase backbone between the number two and three main bearing supports, and the number one, two, and three camshaft journal supports. The number one, two, three, four, and five main crankshaft main bearing supports exhibited fretting wear scars, and the number two and three supports exhibited mechanical damage from bearing shift and rotation. Additionally, the number two intermediate crankshaft main bearings had extruded from their crankshaft positions in the left and right case halves. An unapproved red sealant had been applied to the crankcase backbone. The above signatures are all consistent with an engine crankcase assembly that had lost its through-bolt torque. The crankshaft was fractured through at the number four short cheek between the number two main bearing journal and the number three connecting rod journal. A metallurgical examination of the fracture surface revealed crack arrest marks, which were indicative of a fatigue fracture which emanated from the surface of the number two main bearing journal. The heat treatment of the crankshaft met the manufacturer’s specifications. An examination of the engine logbooks revealed that the engine’s total time was about 1,778 hours and it had about 500 hours since the last major overhaul. The engine’s last overhaul was conducted on September 30, 1986, almost 23 years since the last major overhaul. The engine manufacturer recommends that when the aircraft is used in aerial spraying, the engine be overhauled after an accumulation of 1,200 hours or twelve (12) years, whichever occurs first. ## Factual narrative On July 16, 2009, at 0640 central daylight time, a Cessna A188B, N9747G, sustained substantial damage during a forced landing to a field near Suring, Wisconsin, after a loss of engine power. The pilot was not injured. The 14 CFR Part 137 aerial application flight had departed from a local field and was maneuvering when the loss of power occurred. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed. The pilot reported that the airplane was operating normally during the previous flights prior to the accident flight. He reported that on the accident flight, the engine began to run very rough during a turn at low altitude. The engine suddenly seized so he made an emergency landing to a wheat field. During the landing, the left main gear collapsed and the left wing and nose of the aircraft dug into the soft soil, sustaining substantial damage. The inspection of the engine confirmed that it had seized. The 300 horsepower Continental IO-520-D engine, serial number 572952, was shipped to the engine manufacturer for a teardown inspection. The teardown inspection revealed that the exterior crankcase exhibited minimal exterior damage. The number one, two, three, four, and five main bearing supports exhibited fretting. The number three main bearing support also exhibited main bearing shift. The crankcase backbone exhibited fretting between the number two and three main bearing supports. A red sealant had been applied to the crankcase backbone. The number one, two, and three camshaft journal supports exhibited fretting. The number two crankshaft main bearings had extruded from their crankshaft positions in the left and right case halves. The bearings exhibited mechanical damage that was consistent with bearing shift, rotation, and extrusion. Fragments of the bearing were found in the oil sump. The number three crankshaft main bearings exhibited mechanical damage that was consistent with bearing shift. The babbit was smeared, exposing the copper layer. The number three connecting rod exhibited mechanical damage and was fractured at the base of the I-beam. Fragments of the connecting rod cap exhibited mechanical damage. Fragments of connecting rod bolts and nuts were fractured through and exhibited mechanical damage consistent with overload signatures. The crankshaft was fractured through at the number four short cheek at the number two main journal. A metallurgical examination of the fracture surface revealed crack arrest marks, which were indicative of a fatigue fracture which emanated from the surface. An examination of the engine logbooks revealed that engine’s total time was about 1,778 hours and it had about 500 hours since the last major overhaul. The engine’s last overhaul was conducted on September 30, 1986. The last annual inspection was conducted on October 23, 2008. The Teledyne Continental Aircraft Engine, Service Information Letter, SIL98-9A, issued on November 17, 1998, recommended that an IO-520-Dengine be overhauled every 1,700 hours or at least every twelve (12) years. It recommended that aircraft used in aerial spraying should have the engine overhauled after the accumulation of 1,200 hours or twelve (12) years, whichever occurs first. ## Aircraft - Registration: [N9747G](https://openairdocs.org/aircraft/N9747G), registered now, S/N 18801587T (OpenAirDocs) - Reported make and model: CESSNA A188B - Registry model: [Cessna A188B](https://openairdocs.org/model/cessna-a188b) (registry code 2073005) (OpenAirDocs) - Registry engine: [Continental IO-520 series](https://openairdocs.org/engine/continental-io-520-series) (registry code 17032, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18801587T - Airframe hours: 2211 - Engines: Continental IO-520-D 300 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Nicolet Air LLC - Registered owner: Nicolet Air LLC - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, October 23, 2008 - Departed: Suring, WI - Destination: Private Field, WI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2; last flight review February 5, 2009; seat: center; flight hours: 3,800 total, 50 in this make and model, 3,660 as pilot in command, 94 in the last 90 days, 18 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 52 °F - Altimeter: 29.87 inHg - Observed at: GRB, 30 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 20090716048299A](https://openairdocs.org/incident/20090716048299A), Jul 16, 2009: Cessna A188B, Suring, WI, Substantial damage. Approzimately 0640 local, N9747G experienced engine failure while conducting aerial applications. The pilot made an emergency landing in a nearby wheat field… ## Other investigations on N9747G (1) 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. - [NTSB CHI92DTG06](https://openairdocs.org/ntsb/CHI92DTG06), Sep 14, 1992: Cessna 188B (N9747G), Cogswell, ND, substantial damage. Probable cause: LOSS OF ENGINE POWER AS A RESULT OF A COMPLETE PISTON FAILURE. ## Docket (4 files) The files NTSB released with the investigation on March 4, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=74325. 2.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 528 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40326127&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Engine Logbook Entries (item 2, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40326109&FileExtension=.PDF&FileName=Engine%20Logbook%20Entries-Master.PDF - Teledyne Service Information Letter (item 3, .PDF, 271 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40326110&FileExtension=.PDF&FileName=Teledyne%20Service%20Information%20Letter-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 381 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40326112&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-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. --- 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.