# NTSB CEN10FA521: Cessna P210N, N4632A, Caledonia, MI, September 6, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Field investigation · Final report - Date: September 6, 2010, 08:45 local (12:45 UTC) - Place: Caledonia, MI - Coordinates: 42.794723, -85.516113 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.7947&lon=-85.5161&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report June 20, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration, Teledyne Continental Motors - NTSB case key (mKey): 77206 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN10FA521 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/77206/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=77206 - Page: https://openairdocs.org/ntsb/CEN10FA521 ## Probable cause A loss of engine power as a result of a fatigue failure of the crankshaft due to the loss of engine case through-bolt torque. Contributing to the accident was a mechanic's use of incorrect hardware. ## 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 P210N, 6 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073454), [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 P210N, 6 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073454), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna P210N, 2 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=2073454), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna P210N, 3 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=2073454), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Maintenance personnel (probable cause); cases with it: [Cessna P210N, 6 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=2073454), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna P210N, 20 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073454), [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 P210N, 16 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073454), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot and certified flight instructor were in a holding pattern during an instrument proficiency check when they heard a bang from the airplane's engine area. They initiated a forced landing and the airplane impacted terrain at the base of a hill. Fuel leaked and a ground fire ensued, resulting in substantial damage to the left wing. No airframe preimpact anomalies were observed on-scene. An engine teardown inspection revealed a separation of the crankshaft No. 3 short cheek consistent with fatigue. Additionally, the No. 2 lower through-bolt had the lowest torque value of all bolts and incorrect hardware was used on that through-bolt. Fretting was observed on the mating surfaces of the main bearing supports near the No. 2 through-bolt and its bearing had spun out of its support. Engine logbook entries indicated a mechanic replaced cylinders that would have required the removal and installation of hardware on the No. 2 through-bolt, approximately 19 months prior to the accident. ## Factual narrative On September 6, 2010, about 0845 eastern daylight time, a Cessna P210N, N4632A, operated by Centurion Aviation LLC and piloted by a commercial pilot with a certificated flight instructor (CFI) on board, sustained substantial damage when it impacted terrain during a forced landing following an in-flight loss of engine power while maneuvering near Caledonia, Michigan. A post-impact ground fire occurred. The instructional flight was operating under 14 Code of Federal Regulations Part 91 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. Both the CFI and the commercial pilot reported no injuries. The local flight departed from the Gerald R. Ford International Airport (GRR), near Grand Rapids, Michigan, about 0800. The pilot reported that the purpose of the flight was to conduct an instrument proficiency check (IPC). The pilot stated that the airplane was fueled to full prior to departure. He indicated that during the IPC he was cleared by GRR air traffic controllers to climb to 4,000 feet above mean sea level and hold as published over a GRR navigational aid. The pilot said that while he was starting the hold’s outbound leg, he heard “a large bang from the engine area.” The pilot removed his view limiting devices and turned north toward GRR. The CFI advised GRR air traffic controllers that the flight had a problem and were returning to GRR. The pilot and CFI realized the airplane had no engine power and they agreed “to do an off field landing.” The pilot set up for an approach to an alfalfa field. The pilot stated that the terrain was rolling and the airplane impacted terrain at the base of a hill in the field where its nose gear separated. The airplane “careened sideways” into a corn field and came to rest in the corn field. Fuel leaked out of the left wing’s tip tanks and ignited. The pilot turned the airplane’s fuel selector to off. The CFI opened the emergency door and both pilots exited. The fire was extinguished by the local fire department. According to the pilot, the total elapsed time from the "engine loss to crashing was less than 2 minutes.” N4632A, a Cessna P210N, Centurion, serial number P21000810, was a six-place, single engine, full cantilever high-wing, all-metal airplane of semimonocoque construction. The wings were constructed with integral fuel tanks. The airplane was powered by a six-cylinder, horizontally opposed, turbocharged, air-cooled, fuel injected, Teledyne Continental TSIO-520-RCAF engine with serial number 517924. According to airplane logbook excerpts, the engine's number three and five cylinders were replaced on April 17, 2006, and its number one and two cylinders were replaced on February 18, 2007. According to the pilot's accident report, the airplane's last annual inspection was completed on September 3, 2009, and the airplane had accumulated 4,342 hours of total time at that inspection. At 0853, the recorded weather at GRR was: Wind 180 degrees at 11 knots, 10 statutemiles visibility, sky condition broken 12, 000 feet, temperature 18 degrees C, dew point 12 degrees C, altimeter 29.93 inches of mercury. Federal Aviation Administration inspectors examined the wreckage on-scene. No airframe pre-impact anomalies were observed. The airplane’s engine was shipped to the engine manufacturer for a teardown inspection. The crankshaft exhibited a separation of its number three short cheek. The number two lower through-bolt torque was the lowest of all through-bolts found during the engine disassembly. A nut, specified to be used on a cylinder stud, was found installed on that through-bolt. Fretting was observed on the mating surfaces of the main bearing supports near that through-bolt and its bearing had also spun out of its support. The crankshaft separation exhibited beach and ratchet marks. An engine manufacturer metallurgist confirmed that the separation was consistent with fatigue. ## Aircraft - Registration: [N4632A](https://openairdocs.org/deregistered/N4632A-2013-04-09), registration cancelled 2013-04-09, S/N P21000810, built 1982 (OpenAirDocs) - Reported make and model: CESSNA P210N - Registry model: [Cessna P210N](https://openairdocs.org/model/cessna-p210n) (registry code 2073454) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: P21000810 - Airframe hours: 4342 - Engines: CONT MOTOR TSIO-520-RCAF 310 horsepower reciprocating - Damage: Substantial damage - Fire: On-Ground - Flight: Instructional, Part 91 - Operator: Centurion Aviation LLC - Registered owner: Centurion Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, September 3, 2009 - Departed: GRR, Grand Rapids, MI - Destination: GRR, Grand Rapids, MI - Airport: GRR, Gerald R. Ford IAP ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 42; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review May 10, 2010; seat: left; flight hours: 3,300 total, 42 in this make and model, 3,230 as pilot in command, 200 in the last 90 days, 59 in the last 30 days, 5 in the last 24 hours - Flight instructor; age 26; injuries: none; flight instructor, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review November 2, 2009; seat: right; flight hours: 1,800 total, 0 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 180° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: 12,000 ft broken - Temperature: 64 °F, dew point 54 °F - Altimeter: 29.93 inHg - Observed at: GRR, 5 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 20100906045279A](https://openairdocs.org/incident/20100906045279A), Sep 6, 2010: Cessna P210N, Caledonia, MI, Substantial damage. Pilot was practicing holds at 4000 ft. over the grr VOR when he heard a loud bang from the engine area. He then noticed RPM indication had gone to zero. He… ## Docket (5 files) The files NTSB released with the investigation on May 9, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=77206. 3.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345940&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photos - Two embedded images (item 2, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345803&FileExtension=.PDF&FileName=Photos%20-%20Two%20embedded%20images-Master.PDF - Other Pertinent Forms and Reports - Airplane Logbook Excerpts (item 3, .PDF, 208 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345951&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports%20-%20Airplane%20Logbook%20Excerpts-Redacted.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 55 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345807&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Evidence Control Form and Retention / Release of Wreckage Form (item 5, .PDF, 264 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40345934&FileExtension=.PDF&FileName=Evidence%20Control%20Form%20and%20Retention%20%2F%20Release%20of%20Wreckage%20Form-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. --- 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.