# NTSB WPR18LA181: Cessna 172S, N154ME, Phoenix, AZ, June 26, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: June 26, 2018, 10:20 local (17:20 UTC) - Place: Phoenix, AZ - Coordinates: 33.784168, -112.137779 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.7842&lon=-112.1378&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: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA-FSDO - NTSB case key (mKey): 97625 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR18LA181 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/97625/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=97625 - Page: https://openairdocs.org/ntsb/WPR18LA181 ## Probable cause A total loss of engine power due to crankshaft failure as the result of a subsurface fatigue crack. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 172S, 2 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md?model=2072439), [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. - [Maneuvering: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna 172S, 19 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2072439), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490); cases with it: [Cessna 172S, 9 cases](https://openairdocs.org/ntsb-events/490/sequence.md?model=2072439), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis While maneuvering during a local instructional flight, the engine began running rough, and the instructor decided to return to the airport. The engine subsequently lost total power and the propeller stopped rotating. The instructor performed a forced landing to a clearing where the airplane nosed over, resulting in substantial damage. Examination of the engine revealed that the crankshaft was fractured at the No. 4 connecting rod journal. The fracture surface was flat and crack arrest lines were consistent with a fatigue fracture which initiated subsurface. No flaws or embedded particles were observed at the site of the fatigue initiation. The engine was overhauled about 3 years before the accident and had accumulated 2,798 hours of operation since the overhaul. ## Factual narrative On June 26, 2018, about 1020 mountain standard time, a Cessna 172SP airplane, N154ME, was substantially damaged when it was involved in an accident near Phoenix, Arizona. The pilot received minor injuries; the student pilot and one student pilot passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight instructor reported that, while maneuvering about 5,000 ft mean sea level (msl), the vacuum annunciator light illuminated, and he immediately experienced engine roughness. The pilot decided to depart the practice area and return to the airport but did not declare an emergency or report the engine roughness to the tower controller, because he "didn’t anticipate" an engine failure. The instructor positioned the fuel mixture to full rich and turned on the fuel boost pump switch; however, the engine continued to run rough during the return flight. About 8 miles northwest of the airport, the tower controller instructed the pilot to perform a left 360° turn. After completing the turn, the engine lost all power and the propeller stopped rotating. The instructor configured the airplane for best glide and located a forced landing site. During the landing roll, the airplane impacted rocks and vegetation and nosed over. An examination of the engine revealed that the crankshaft fractured separated at the No. 4 connecting rod journal. The No. 4 connecting rod was separated at the I-beam near the piston attachment and moved freely on the crankshaft. The fractured crankshaft was examined at the NTSB Materials Laboratory. The fracture surface was relatively flat, with crack arrest lines extending from close to the outer diameter of the journal on the web side. The crack arrest lines propagated from a subsurface location about 0.05 inches inboard of the outer diameter. The flat fracture surface and crack arrest lines were consistent with fatigue fracture. No flaws or embedded particles were observed at the site of the fatigue initiation. The engine was overhauled and installed on the accident airplane in May 2015. At the time of the accident, the engine had 2,798 hours of operation since the overhaul. ## Aircraft - Registration: [N154ME](https://openairdocs.org/deregistered/N154ME-2020-06-05), registration cancelled 2020-06-05, S/N 172S8534, built 2000 (OpenAirDocs) - Reported make and model: CESSNA 172S (S) - Registry model: [Cessna 172S](https://openairdocs.org/model/cessna-172s) (registry code 2072439) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 172S8534 - Year built: 2000 - Engines: 180 horsepower reciprocating - Damage: Substantial damage - Flight: Business, Part 91 - Airworthiness certificate: Standard, Utility; Standard, Normal - Departed: DVT, Phoenix, AZ - Destination: DVT, Phoenix, AZ - Airport: DVT, Phoenix Deer Valley ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: minor; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review June 21, 2018; seat: right; restraint: 3-point; flight hours: 584 total, 484 in this make and model, 453 as pilot in command, 72 in the last 90 days, 45 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Lowest ceiling: none - Temperature: 93 °F, dew point 34 °F - Altimeter: 29.92 inHg - Observed at: KDVT, 6 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 20180626025209A](https://openairdocs.org/incident/20180626025209A), Jun 26, 2018: Cessna 172S, Phoenix, AZ, Substantial damage. On June 26, 2018, at approximately 1020 mountain standard time, a Cessna 172SP airplane, N154ME, serial number - 172S8534, was substantially damaged during a… ## Docket (6 files) The files NTSB released with the investigation on June 22, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=97625. 25.0 MB in all. - Materials laboratory study report (item 1, PDF, 7 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12389107&FileExtension=pdf&FileName=Materials%20Lab%20Factual%20Report%20(WPR18LA181)-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 10 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11945663&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - NTSB engine examination summary (item 3, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11945653&FileExtension=pdf&FileName=WPR18LA181%20Engine%20Examination%20Summary-Rel.pdf - Maintenance logbook excerpts (item 4, PDF, 3 pages, 19.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11946001&FileExtension=pdf&FileName=Logbook%20Excerpts_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 5, PDF, 1 page, 64 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11944869&FileExtension=pdf&FileName=Retention-Release-of-Wreckage-Form%202015_Redacted-Rel.pdf - Phoenix pd-photo array (item 6, PDF, 4 pages, 4 photos, 695 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12500829&FileExtension=pdf&FileName=Photo%20Array-PHX%20PD%20v3-Rel.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.