# NTSB CEN12LA437: Piper PA-25-235, N8801L, Mott, ND, July 12, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 12, 2012, 07:00 local (13:00 UTC) - Place: Mott, ND - Coordinates: 46.359722, -102.323059 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.3597&lon=-102.3231&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 October 9, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - Fargo FSDO - NTSB case key (mKey): 84291 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA437 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84291/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84291 - Page: https://openairdocs.org/ntsb/CEN12LA437 ## Probable cause The rupture of a corroded oil line, which resulted in a total loss of engine power due to oil starvation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Piper PA-25-235, 1 case](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=7102504), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Engine (reciprocating): recip eng oil sys](https://openairdocs.org/ntsb-findings/01058550): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Piper PA-25-235, 1 case](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=7102504), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Piper PA-25-235, 2 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=7102504), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/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: [Piper PA-25-235, 10 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7102504), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Piper PA-25-235, 11 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=7102504), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-25-235, 28 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7102504), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that the engine experienced a loss of oil pressure and power during aerial-application flight maneuvers. The airplane impacted a hay bale and roadside ditch during the subsequent forced landing. A postaccident examination revealed that one of the oil lines associated with the oil-cooler had ruptured. The oil line’s reinforcing steel braiding was corroded, and a majority of the individual steel strands were fractured in the immediate area surrounding the rupture. A review of available records indicated that there were no unresolved maintenance items and that there was no history of engine oil leaks since the last engine overhaul. The installation date and total time in-service of the ruptured engine oil line could not be determined from the available maintenance information. ## Factual narrative On July 12, 2012, at 0700 mountain daylight time, a Piper model PA-25-235 airplane, N8801L, was substantially damaged during a forced landing following a loss of engine power near Mott, North Dakota. The commercial pilot was not injured. The airplane was registered to and operated by the pilot, under the provisions of 14 Code of Federal Regulations Part 137 without a flight plan. Day visual meteorological conditions prevailed for the local aerial-application flight that originated from Mott Municipal Airport (3P3), Mott, North Dakota, about 0615. The pilot reported that the engine experienced a loss of oil pressure and power during aerial-application flight maneuvers. The airplane impacted a hay bale while the pilot attempted to maneuver the airplane to a nearby road during the forced landing. The airplane subsequently impacted a roadside ditch. The airplane sustained substantial damage to the fuselage and left wing during the accident. A postaccident examination of the airframe revealed engine oil covering the lower fuselage, left fuselage sidewall, left horizontal stabilizer, and the left elevator. An external examination of the engine did not reveal any crankcase damage. The engine oil dip-stick indicated that there was little to no available oil within the engine. The oil lines associated with the oil-cooler were removed for examination. One of the oil lines had ruptured about 13-inches from the oil-cooler. The oil line reinforcing steel braiding was corroded and a majority of the individual steel strands were fractured in the immediate area surrounding the rupture. The engine, a Lycoming O-540-B2C5, serial number L-14001-40, had accumulated 1,618 hours since the last overhaul, which was completed on April 1, 1987. A review of available records indicated that there were no unresolved maintenance items and that there was no history of engine oil leaks since the last engine overhaul. No engine related issues were identified during the last annual inspection that was completed on August 2, 2011. The airplane had accumulated 46 hours since that annual inspection. The installation date and total time in-service of the ruptured engine oil line could not be determined from the available maintenance information. The closest weather observing station was at Hettinger Municipal Airport (KHEI), located about 25 miles southwest of the accident site. At 0653, the KHEI automated surface observing system reported the following weather conditions: wind 240 degrees at 5 knots, visibility 10 miles, sky clear, temperature 18 degrees Celsius, dew point 14 degrees Celsius, altimeter setting 29.99 inches of mercury. ## Aircraft - Registration: [N8801L](https://openairdocs.org/deregistered/N8801L-2018-03-07), registration cancelled 2018-03-07, S/N 25-5238, built 1970 (OpenAirDocs) - Reported make and model: PIPER PA-25-235 - Registry model: [Piper PA-25-235](https://openairdocs.org/model/piper-pa-25-235) (registry code 7102504) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25-5238 - Airframe hours: 3512 - Engines: Lycoming O-540-B2C5 235 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, August 2, 2011, 46 hours before - Departed: 3P3, Mott, ND - Destination: 3P3, Mott, ND ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 7, 2012; seat: single; flight hours: 4,300 total, 2,871 in this make and model, 39 in the last 90 days, 29 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 240° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 57 °F - Altimeter: 29.98 inHg - Observed at: KHEI, 25 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 20120712017379A](https://openairdocs.org/incident/20120712017379A), Jul 12, 2012: Piper PA-25-235, Mott, ND, Substantial damage. Suspect loss of oil from oil line or fitting leading to engine failure/seizing. NTSB is coordinating engine tear down. ## Docket (6 files) The files NTSB released with the investigation on August 22, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84291. 1.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 818 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375474&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Airplane Mechanic Statement (item 2, .PDF, 48 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375475&FileExtension=.PDF&FileName=Airplane%20Mechanic%20Statement-Redacted.PDF - Memorandum of Maintenance Records Review, N8801L (item 3, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375482&FileExtension=.PDF&FileName=Memorandum%20of%20Maintenance%20Records%20Review,%20N8801L-Master.PDF - Weather Reports (item 4, .PDF, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375477&FileExtension=.PDF&FileName=Weather%20Reports-Master.PDF - Photo 01 - Overview of ruptured oil line (item 5, .PDF, 331 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375478&FileExtension=.PDF&FileName=Photo%2001%20-%20Overview%20of%20ruptured%20oil%20line-Master.PDF - Photo 02 - Oil line rupture close-up (item 6, .PDF, 283 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40375479&FileExtension=.PDF&FileName=Photo%2002%20-%20Oil%20line%20rupture%20close-up-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.