# NTSB WPR17LA038: Cessna 182A, N6077B, Safford, AZ, November 24, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: November 24, 2016, 08:50 local (15:50 UTC) - Place: Safford, AZ - Coordinates: 32.871665, -109.635276 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.8717&lon=-109.6353&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: No injuries - Injuries: 4 uninjured - Status: Completed, report September 10, 2018 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration, Continental Motors Inc. - NTSB case key (mKey): 94502 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR17LA038 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94502/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94502 - Page: https://openairdocs.org/ntsb/WPR17LA038 ## Probable cause The total loss of engine power due to the failure of the No. 5 piston, piston pin, or connecting rod assembly for reasons that could not be determined due to the severity of the post fracture damage. ## 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 · Failure (probable cause); cases with it: [Cessna 182A, 2 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2072704), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 182A, 9 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072704), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined; cases with it: [Cessna 182A, 9 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2072704), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Cessna 182A, 1 case](https://openairdocs.org/ntsb-events/340/sequence.md?model=2072704), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 182A, 20 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072704), [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 182A, 15 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072704), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 182A, 34 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072704), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) - [Landing-landing roll: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Cessna 182A, 6 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2072704), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The commercial pilot reported that, during cruise flight, he noticed the oil pressure begin to fluctuate and he decided to return to the departure airport. As the airplane neared the airport, the engine experienced a total loss of power, and the pilot initiated an off-airport forced landing. During the landing roll, the airplane struck two dirt berms and the nose landing gear collapsed. Postaccident examination of the engine revealed that the connecting rods, pistons, piston pins, bearings, and bushings in cylinder Nos. 5 and 6 exhibited numerous fractures and severe deformation. Due to the widespread postfracture damage to many of the fracture surfaces, it was not possible to determine which component fractured first. The No. 5 cylinder connecting rod and cap were severely deformed and battered. The piston pin had fractured in multiple places, and the underside of the piston exhibited gouging consistent with impact from adjacent components. In addition, the skirt and pin boss of the piston had fractured in multiple locations. The features on these fracture surfaces were generally consistent with having fractured in and around the pin boss; therefore, the likely initial point of failure in cylinder No. 5 was either the piston pin boss, the piston pin, or the pin side of the connecting rod. Based on the degree of damage observed, the components in the No. 5 cylinder likely began to fracture first, followed by fractures in the No. 6 cylinder. ## Factual narrative On November 24, 2016, about 0850 mountain standard time, a Cessna 182A airplane, N6077B, was substantially damaged during a forced landing following a loss of engine power near Safford, Arizona. The commercial pilot and the 3 passengers were not injured. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal cross-country flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from the Safford Regional Airport (SAD) at 0815, with an intended destination of Holbrook, Arizona. The pilot reported that during cruise flight at 8,500 ft mean sea level, he noticed that the oil pressure began to fluctuate and he decided to return to the airport. When the airplane was about 4 miles north of SAD, the engine lost power and he initiated a forced landing to an area of open desert. During the landing roll, the airplane struck two dirt berms and the nose wheel collapsed. Post-accident examination of the airplane by a Federal Aviation Administration inspector revealed that the forward portion of the fuselage structure was substantially damaged. Examination of the engine was conducted on July 13, 2017, under the supervision of the National Transportation Safety Board investigator-in-charge. All engine accessories with the exception of the carburetor, which was removed from the engine prior to shipment, remained attached. Two holes in the crankcase above the number 5 and 6 cylinders were observed. Silicone was observed around the crankshaft nose seal. The crankcase exhibited normal operational signatures mostly throughout with the exception of mechanical damage surrounding the number 5 and 6 cylinder bays. Crankcase main bearings #1, #2, and #4 exhibited normal operational signatures. The #3 main bearing exhibited wear into the copper layer. The camshaft exhibited mechanical damage to the cylinder 5 and 6 lobes. The number 5 crankshaft connecting rod bearing journal exhibited thermal discoloration along with mechanical damage. The number 6 crankshaft connecting rod bearing journal exhibited slight mechanical damage. The remainder of the crankshaft exhibited normal operational signatures. During disassembly of the engine, cylinders 1, 2, 3, and 4 exhibited normal operational signatures. However, cylinder number 5 exhibited mechanical damage to the cylinder skirt. The piston remained inside the cylinder with mechanical damage to the piston skirt. The piston pin was separated from the piston and the connecting rod. Cylinder number 6 exhibited mechanical damage to the cylinder skirt. The piston remained inside the cylinder and exhibited mechanical damage. The connecting rod remained attached to the piston via the piston pin. The connecting rod cap was separated as well as part of the lower portion of the cap. The remaining portion of the rod cap was connected to the yoke. The bolt was missing, and the bolt hole appeared elongated. Theremains of the number 5 and 6 pistons, rings, piston pins, and connecting rods were sent to the NTSB Materials Laboratory and subsequently examined by a Material Research Engineer. The cylinder number 5 pistons, rings, piston pin, connecting rod, and bearings revealed that they all exhibited damage significant enough to deform the outer surfaces. All of this damage was found consistent with post-fracture damage while the engine was still running. The pieces of the number 5 connecting rod exhibited severe batter and deformation. The bushing and bearing pieces were damaged and folded onto themselves. The connecting rod bolts were both fractured at midlength, consistent with where the faces of the connecting rod cap and connecting rod mate. Both bolts exhibited necking adjacent to their fracture surfaces. The fracture surfaces were generally oriented 90° toward the bolt length and exhibited a rough texture and dull luster, consistent with tensile overstress fractures. The most notable feature on pin side bore of the connecting rod was the fracture at the neck yoke of the rod web. A portion of the pin bore wall was sectioned away to observe the fracture surfaces and exhibited deformation consistent with having been twisted about the piston pin. The inner bore surfaces exhibited circumferential scoring marks. The three portions of the connecting rod cap had fractured in two places, and the previously curved cap had been deformed outward in an almost flat orientation. The fracture surfaces, along with the other surfaces of the cap, exhibited severe post-fracture damage in the form of batter, gouging, and scraping. The gouging marks on the inside bearing surface were consistent with either the cap being bounced around after fracture/separation or having an adjacent object impressed into the cap. Both endcaps of the piston pin had fractured away, but only one of the cap remnants were found. The mating fracture surfaces of the pin and pin endcap fragment had been extensively damaged, consistent with post-fracture impact. No discernible information could be obtained from examination of the fracture surfaces. The majority of damage to the piston was present on the underside of the part to the skirt flanges. The crown or head of the piston facing the cylinder interior exhibited some combustion deposits, but there were no features consistent with severe wear, impact, or thermal damage. The underside of the piston exhibited small gouge and batter marks, consistent with impact with multiple metallic pieces. The lower portions of the piston, including those surrounding the piston pin boss, had fractured into multiple pieces. All of the fracture surfaces examined exhibited features consistent with overstress failure of aluminum castings—rough and tortuous surfaces, dull luster, and no indications of pre-existing cracks or discontinuities. Examination of the chevron marks and river patterns on the piston fracture surfaces revealed that they were consistent withfracture beginning from the inside of the piston. Many of the fracture features were consistent with having emanated from the piston pin boss. The components from the number 6 cylinder exhibited damage significant enough to deform the outer surfaces. This damage was less than those observed on the components of the number 5 cylinder. The damage observed was consistent with post-fracture damage while the engine was still running. The number 6 connecting rod components had been damaged with batter and other post-fracture damage, but the degree of damage was less than that of the components of the number 5 connecting rod. The bolts from the connecting rod were fractured at midlength, consistent with where the rod and cap mate. The areas on the bolts adjacent to their fracture surfaces thinned down or necked. The fracture surfaces themselves exhibited a 45° slant, consistent with tensile overstress. The crankshaft side of the connecting rod had fractured near the yoke neck. The pin side of the rod arm was relatively undamaged. The bushing was still present inside the pin bore of the rod. The inner bearing surface of the connecting rod that had faced a crankshaft journal surface exhibited some wear marks, consistent with sliding in a lateral direction. In addition, some material smearing outward of the bearing surface was present. The fracture surface of the rod arm was generally dull in luster, with post-fracture iron oxide (rust) corrosion and smearing damage on the outer regions of the fracture surface. Examination of the undamaged portions of the fracture surface using an SEM revealed dimple rupture, consistent with overstress. For further information, see the Materials Laboratory Factual Report within the public docket for this accident. Review of the engine logbooks revealed that the engine was overhauled on May 20, 1996, at a tachometer time of 3,686 hours. The most recent 100-hour/annual inspection was completed on October 19, 2016, at an engine time since overhaul of 1,556.9 hours. ## Aircraft - Registration: [N6077B](https://openairdocs.org/deregistered/N6077B-2018-10-01), registration cancelled 2018-10-01, S/N 34077, built 1957 (OpenAirDocs) - Reported make and model: CESSNA 182A (A) - Registry model: [Cessna 182A](https://openairdocs.org/model/cessna-182a) (registry code 2072704) (OpenAirDocs) - Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 34077 - Year built: 1957 - Airframe hours: 5243.6 - Engines: CONT MOTOR O-470 SERIES 230 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 19, 2016 - Departed: SAD, Safford, AZ - Destination: Holbrook, AZ - Airport: SAD, Safford Rgnl - Equipment: Unknown ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review May 19, 2016; seat: left; restraint: 3-point; flight hours: 15,140 total, 954 in this make and model, 13,700 as pilot in command, 61 in the last 90 days, 18 in the last 30 days, 0.6 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 30 °F - Altimeter: 30.25 inHg - Observed at: KSAD, 1 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 20161124016439A](https://openairdocs.org/incident/20161124016439A), Nov 24, 2016: Cessna 182A, Safford, AZ, Substantial damage. On 11/24/2016 at 0750 MST a C182A tail # N6077B with 4 POB, one POB was an 18 month infant and one POB was pregnant. No injuries. The pilot noticed an abnormal… ## Docket (6 files) The files NTSB released with the investigation on July 5, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94502. 16.2 MB in all. - Materials Laboratory Factual Report (item 1, .PDF, 6.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464777&FileExtension=.PDF&FileName=Materials%20Laboratory%20Factual%20Report-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464776&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Continental Motors Inc. Report (item 3, .PDF, 7.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464778&FileExtension=.PDF&FileName=Continental%20Motors%20Inc.%20Report-Master.PDF - Evidence Control Form (item 4, .PDF, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464779&FileExtension=.PDF&FileName=Evidence%20Control%20Form-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 5, .PDF, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464780&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 6, .PDF, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464781&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.