# NTSB CEN15LA170: Maule M 7-260C, N55000, Oregon, MO, March 10, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 10, 2015, 12:15 local (17:15 UTC) - Place: Oregon, MO - Coordinates: 39.986946, -95.144996 - Nearby events: https://openairdocs.org/map.md?lat=39.9869&lon=-95.1450&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 26, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA- Kansas City FSDO - NTSB case key (mKey): 90864 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA170 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90864/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90864 - Page: https://openairdocs.org/ntsb/CEN15LA170 ## Probable cause Engine vibration for reasons that could not be determined based on the available evidence. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Maule M-7-260C, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=5470112), [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: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Maule M-7-260C, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=5470112), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Maule M-7-260C, 4 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=5470112), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The airline transport pilot was conducting a cross-country personal flight. The pilot reported that, after climbing the airplane to cruise altitude and leaning the fuel mixture, he noted an unusual engine vibration. He enriched the fuel mixture slightly, and the vibration seemed to lessen. After descending and increasing power to level off, the engine vibration worsened, and he chose to perform a precautionary off-airport landing. During the landing, the landing gear "dug in," and the airplane subsequently nosed over. Testing of the engine's fuel system components revealed that the fuel servo fuel flow was slightly richer than the specified service limits. However, according to the pilot's report, the initial engine vibration did not occur until he leaned the fuel mixture at cruise altitude, indicating that the slightly rich calibration of the fuel servo likely was not associated with the engine vibration described by the pilot. Based on the available evidence, the reason for the engine vibration could not be determined. ## Factual narrative On March 10, 2015, about 1210 central daylight time, a Maule M7 airplane, N55000, sustained substantial damage when it nosed over during a precautionary landing near Oregon, Missouri, following a partial loss of engine power during cruise flight. The pilot was not injured. The airplane sustained substantial damage to the vertical stabilizer and rudder. The aircraft was registered to Aardvark Aircraft Acquisition LLC and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The flight originated from the North Omaha Airport (3NO), Omaha, Nebraska, about 1125 and was destined for the Rosecrans Memorial Airport (STJ), St Joseph, Missouri.The pilot reported that after climbing to cruise altitude and leaning the engine he noted an unusual engine vibration. He responded by enriching the fuel mixture slightly above normal and the vibration seemed better. After descending and increasing power to level off, the engine vibration became "much worse", and he elected to perform an off-airport precautionary landing. He stated that the landing was normal but during the landing roll, the main landing gear "dug in" and the airplane nosed over. Postaccident examination of the airplane did not reveal any preimpact anomalies. The engine fuel servo, flow divider and nozzles were sent to the manufacturer's facility for testing under the direct supervision of NTSB investigators. The flow divider was tested and met all production test standards. The fuel nozzles were not flow tested but did not have any evidence of obstruction. The fuel servo was tested on the manufacturer's flow bench. The measured fuel flow rates were about 1.5 pounds per hour (1/4 gallon per hour) leaner than specified service limits. ## Aircraft - Registration: [N55000](https://openairdocs.org/aircraft/N55000), registered now, S/N 30031C, built 2003 (OpenAirDocs) - Reported make and model: MAULE M 7-260C (260C) - Registry model: [Maule M-7-260C](https://openairdocs.org/model/maule-m-7-260c) (registry code 5470112) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 30031C - Year built: 2003 - Airframe hours: 890 - Engines: LYCOMING IO-540 SER reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 1, 2014 - Departed: 3NO, OMAHA, NE - Destination: STJ, ST JOSEPH, MO - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; seat: left; restraint: 3-point; flight hours: 18,102 total, 16 in this make and model, 12,875 as pilot in command, 61 in the last 90 days, 17 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 55 °F, dew point 43 °F - Altimeter: 30.01 inHg - Observed at: STJ, 20 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 20150310002309A](https://openairdocs.org/incident/20150310002309A), Mar 10, 2015: Maule M-7-260C, Oregon, MO, Substantial damage. Aircraft departed 3NO enroute to stj. After aircraft climbed to 7500 feet MSL, the pilot attempted to lean engine using normal procedures and the engine began… ## Docket (4 files) The files NTSB released with the investigation on March 8, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90864. 6.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437448&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Evidence Control Form & Return Shipping Verification (item 2, .PDF, 107 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437449&FileExtension=.PDF&FileName=Evidence%20Control%20Form%20%26%20Return%20Shipping%20Verification-Master.PDF - Fuel System Bench Testing Results (item 3, .PDF, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437450&FileExtension=.PDF&FileName=Fuel%20System%20Bench%20Testing%20Results-Master.PDF - Aircraft Maintenance Record Excerpts (item 4, .PDF, 905 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437457&FileExtension=.PDF&FileName=Aircraft%20Maintenance%20Record%20Excerpts-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.