# NTSB WPR12LA161: Piper PA-28-181, N30997, Casper, WY, April 8, 2012 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: April 7, 2012, 20:25 local (Apr 8, 2012, 02:25 UTC) - Place: Casper, WY - Coordinates: 43.033611, -106.583053 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.0336&lon=-106.5831&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: Minor injuries - Injuries: 2 minor - Status: Completed, report November 26, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration FSDO - NTSB case key (mKey): 83324 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12LA161 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83324/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83324 - Page: https://openairdocs.org/ntsb/WPR12LA161 ## Probable cause A total loss of engine power during cruise flight due to a failed piston pin plug, which resulted in engine oil contamination and subsequent oil starvation. Contributing to the loss of power was the failure of maintenance personnel to identify contaminants produced by the failing plug during the last oil filter inspection. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Piper PA-28-181, 6 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=7102807), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Piper PA-28-181, 1 case](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=7102807), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Maintenance/inspections: scheduled maint checks](https://openairdocs.org/ntsb-findings/01010520): Aircraft › Aircraft handling/service · Inadequate inspection (probable cause); cases with it: [Piper PA-28-181, 2 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md?model=7102807), [All aircraft, 76 cases](https://openairdocs.org/ntsb-findings/01010520/cases.md) - [Inspection: scheduled/routine inspection](https://openairdocs.org/ntsb-findings/02061520): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-28-181, 3 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md?model=7102807), [All aircraft, 167 cases](https://openairdocs.org/ntsb-findings/02061520/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft inspection event](https://openairdocs.org/ntsb-events/050); cases with it: [Piper PA-28-181, 1 case](https://openairdocs.org/ntsb-events/050/sequence.md?model=7102807), [All aircraft, 229 cases](https://openairdocs.org/ntsb-events/050/sequence.md) - [Enroute-cruise: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Piper PA-28-181, 26 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7102807), [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: [Piper PA-28-181, 23 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7102807), [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: [Piper PA-28-181, 70 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7102807), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis During cruise flight, the engine sustained a reduction in oil pressure followed by a total loss of power. The student pilot then performed a forced landing into a field. Subsequent examination of the engine revealed that a piston pin plug had disintegrated, the fragments of which contaminated the oil passages and caused oil starvation and the subsequent engine seizure. The engine's manufacturer issued a service instruction warning of such piston pin wear, recommending oil filter element inspection or spectrographic oil analysis at each oil change, not to exceed 50 hours of engine operation. The engine had undergone an oil change about 8 flight hours prior to the accident and the mechanic reported that the oil filter element appeared to be normal. Based on the relatively short period between the last oil filter inspection and the engine failure, the oil filter inspection should have revealed ample evidence of piston pin wear. ## Factual narrative HISTORY OF FLIGHT On April 7, 2012, about 2025 mountain daylight time, a Piper PA-28-181, N30997, landed in a field following a loss of engine power near Casper, Wyoming. The pilot was operating the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. The student pilot and passenger were not injured. The cross-country flight departed Riverton Regional Airport, Riverton, Wyoming, about 1930, with a planned destination of Mitchell Municipal Airport, Mitchell, South Dakota. Visual meteorological conditions prevailed, and no flight plan had been filed. The pilot reported that after reaching cruise altitude he observed a decrease in engine oil pressure. He continued to monitor the pressure indicator, and did not see a corresponding increase in oil temperature. He began to divert the airplane to Casper, and a few minutes later the engine speed began to decrease, with an accompanying engine vibration. He continued the diversion as the engine progressively began to lose power. The engine eventually lost all power, and the propeller stopped rotating. The pilot was not in communication with any air traffic control facility at the time of the power loss, and subsequently transmitted a mayday call on the guard frequency. This transmission was heard by a United Airlines flight crew, who relayed the information to the Federal Aviation Administration (FAA) Salt Lake City Air Route Traffic Control Center (ARTCC). The pilot subsequently landed in a field, and the airplane sustained substantial damage to the fuselage during the landing sequence. An FAA inspector responded to the accident site, and reported oil was still present within the engine crankcase, with fuel present in both wing tanks. AIRCRAFT INFORMATION The airplane was equipped with a four-cylinder, normally aspirated Lycoming O-360-A4M engine, serial number L-24739-36A. Maintenance records revealed that the engine had undergone a factory overhaul, which was completed on December 14, 1998, about 770 flight hours prior to the accident. The most recent annual inspection was accomplished on June 15, 2011, at a total airframe time of 2,710 flight hours. TESTS AND RESEARCH Engine Exam The engine was removed from the airframe, and examined at the engine overhaul facilities of Central Cylinder, Omaha, Nebraska, in the presence of an FAA inspector. Disassembly revealed that the oil filter element and screen were clogged with shiny metallic debris. One of the number four piston pin plugs had disintegrated, with its remnants remaining within the pin cavity and plug area. The associated piston skirt walls exhibited plug-shaped gouging damage, which extended into the oil scraper piston ring groove. Additionally, the oil scraper ring was severed in the gouged area. Further engine disassembly revealed metallic particle contamination throughout the engine's internal surfaces. The connecting rod bearings had become extruded at all four locations on the crankshaft rod journals, and the pistonpins sustained radial grooves and scoring. Lycoming Service Instruction Lycoming Service Instruction 1492, originally issued on December 30, 1998, and updated to revision D on March 20, 2009, documented piston pin plug wear inspections. The service instruction is applicable to all Lycoming new or factory rebuilt, or factory overhauled engines shipped from Lycoming after January 1, 1994, and all engines (except O-235 models) which have had a Lycoming Cylinder Kit installed after January 1, 1994. Compliance is required at the next oil change/oil filter replacement, not to exceed 50 hours of engine operation. According to the instruction, an increase in incidents of abnormally worn piston pin plugs had occurred in some units shipped after January 1, 1994. The letter goes on to state that evidence of such wear can be detected by use of an oil filter content inspection, or spectrographic oil analysis. FAA regulations do not require compliance with manufacturer’s service instructions. Oil and Filter Analysis Examination of the airplane's maintenance records revealed that an engine oil and filter change was performed on January 26, 2012, 7.84 flight hours prior to the accident. The logbook entry stated, “Drained oil. Removed oil filter, cut open and inspected. No defects noted.” The entry did not indicate that an oil analysis had been performed. According to the maintenance records, since overhaul, the oil filter element had been examined four times with negative results, and oil samples were removed twice for analysis. No records were located indicating the results of the oil analysis, and the owner, who purchased the airplane in August 2009, stated that he was unaware of an oil analysis ever being performed. The NTSB investigator-in-charge requested records from four of the major oil analysis laboratories. Only one laboratory had records of the engine being subject to an oil analysis, which occurred in April 2008. According to that report, the engine had accrued 518 total flight hours at that time. The results indicated an aluminum value of 2 parts per million, with diagnostic recommendations of “All values appear normal.” ADDITIONAL INFORMATION According to 14 Code of Federal Regulations, Part 61.89, a student pilot may not act as pilot-in-command of an aircraft that is carrying a passenger. ## Aircraft - Registration: [N30997](https://openairdocs.org/deregistered/N30997-2013-06-18), registration cancelled 2013-06-18, S/N 28-7890460, built 1978 (OpenAirDocs) - Reported make and model: PIPER PA-28-181 - Registry model: [Piper PA-28-181](https://openairdocs.org/model/piper-pa-28-181) (registry code 7102807) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7890460 - Airframe hours: 2710 - Engines: LYCOMING O-360 SERIES 180 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 15, 2011, 100 hours before - Departed: KRIW, Riverton, WY - Destination: KMHE, Mitchell, SD - Airport: CPR, Casper ## Flight crew As NTSB recorded them. NTSB leaves out names. - Student pilot; age 59; injuries: none; student; medical: class 3, with waivers/limitations; seat: left; flight hours: 150 total, 150 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 16 knots, gusting 22 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 3 °F - Altimeter: 30.19 inHg - Observed at: KCPR, 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 20120407006439A](https://openairdocs.org/incident/20120407006439A), Apr 7, 2012: Piper PA-28-181, Nw Of Casper, WY, Substantial damage. On 04/07/2012, at approximately 1830 MDT, N30997, a Piper model PA-28-181 aircraft sustained substantial damage when it impacted terrain north west of Casper,… ## Docket (8 files) The files NTSB released with the investigation on October 3, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83324. 1.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 947 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40372719&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1 – Oil Filter Element (item 2, .PDF, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375876&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Oil%20Filter%20Element-Master.PDF - Photo 2 – Piston Pin Plug Remnants (item 3, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375877&FileExtension=.PDF&FileName=Photo%202%20%E2%80%93%20Piston%20Pin%20Plug%20Remnants-Master.PDF - Photo 3 – Piston Pin Skirt (item 4, .PDF, 59 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375878&FileExtension=.PDF&FileName=Photo%203%20%E2%80%93%20Piston%20Pin%20Skirt-Master.PDF - Photo 4 - Piston Rod Main Bearing (item 5, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40376440&FileExtension=.PDF&FileName=Photo%204%20-%20Piston%20Rod%20Main%20Bearing-Master.PDF - Oil Analysis Report (item 6, .PDF, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375882&FileExtension=.PDF&FileName=Oil%20Analysis%20Report-Redacted.PDF - Lycoming Service Instruction No 1492D (item 7, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375881&FileExtension=.PDF&FileName=Lycoming%20Service%20Instruction%20No%201492D-Master.PDF - Engine and Airframe Maintenance Logbook Excerpts (item 8, .PDF, 409 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40376188&FileExtension=.PDF&FileName=Engine%20and%20Airframe%20Maintenance%20Logbook%20Excerpts-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.