# NTSB WPR09LA077: Cessna R172K, N758FN, Fremont, CA, January 10, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 9, 2009, 22:10 local (Jan 10, 2009, 06:10 UTC) - Place: Fremont, CA - Coordinates: 37.537776, -122.103889 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.5378&lon=-122.1039&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 3, 2010 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Teledyne Continental Motors, Federal Aviation Administration - NTSB case key (mKey): 73210 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA077 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73210/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73210 - Page: https://openairdocs.org/ntsb/WPR09LA077 ## Probable cause The partial loss of engine power during takeoff due to an oil pump/tachometer drive gear failure for undetermined reasons. ## 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 · Failure (probable cause); cases with it: [Cessna R172K, 3 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md?model=2072431), [All aircraft, 130 cases](https://openairdocs.org/ntsb-findings/01058550/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Cessna R172K, 2 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=2072431), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna R172K, 6 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072431), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna R172K, 5 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2072431), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that after takeoff, and during a left turn, he heard a sudden change in the engine sound followed by a loss of power. He stated that he increased and decreased the throttle with little response from the engine and elected to make a precautionary landing onto a nearby levy. During the landing roll on the levy, the airplane veered to the right, exited the levy, and nosed over in a bog. Both wings sustained substantial damage. Examination of the engine revealed that the oil pump/tachometer drive gear separated from the base of its driveshaft. Metallurgical examination revealed that the oil pump drive gear failed at the intersection of the shaft and gear. Scanning electron microscope images of the fracture showed raised and flattened areas typical of contact damage during cyclic loading. The cause of the fracture was not determined. ## Factual narrative On January 9, 2009, at 2210 Pacific standard time, a Cessna R172K, N758FN, sustained substantial damage during a precautionary off-airport landing near Fremont, California, shortly after departure from the Palo Alto Airport of Santa Clara County, Palo Alto, California. The commercial pilot, the sole occupant of the airplane, was not injured. The airplane was owned by the pilot, and operated as a visual flight rules (VFR) personal flight under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91. Night visual meteorological conditions prevailed and no flight plan was filed for the local flight. In a written report to the National Transportation Safety Board, the pilot reported that after takeoff, during a left turn, he heard a "sudden" change in the engine sound followed by a loss of power. He stated "I looked at the oil temperature [gauge] and noticed it on the very low (left side) of the gauge." The pilot reported that he increased and decreased the throttle with "very little" response from the engine and elected to make a precautionary landing onto a nearby levy. During the landing roll on the levy, the airplane veered to the right, exited the levy and nosed over in a bog. Both wings sustained substantial damage. The airplane was recovered from the accident site to a storage facility in Pleasant Grove, California. During the postaccident airframe and engine examination, the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) and a representative from the Federal Aviation Administration (FAA) started the airplane's engine. The engine ran at idle for approximately one minute; oil pressure and tachometer gauge readings were nil, and the engine run was discontinued. The accessory gear cover was removed and the gear assembly was examined. The examination revealed that the oil pump/tachometer drive gear (part number 653236) separated from the base of its respective drive shaft. The drive gear and shaft were removed and shipped to Teledyne Continental Motors, Inc, for further evaluation. The examination was completed at Teledyne Continental Motors (TCM), Materials and Processes Laboratory, Mobile, Alabama. According to the examination report, completed by personnel from TCM, the oil pump/tachometer drive gear failed at the intersection of the shaft and gear. Scanning electron microscope (SEM) images of the fracture showed raised and flattened areas typical of contact damage during cyclic loading. The reason for the fracture was not determined. Review of the engine maintenance logbook revealed that an annual inspection was completed on July 15, 2008, at an engine total time of 4,904 hours; 1,864 hours since major overhaul. ## Aircraft - Registration: [N758FN](https://openairdocs.org/deregistered/N758FN-2010-11-10), registration cancelled 2010-11-10, S/N R1723062 (OpenAirDocs) - Reported make and model: CESSNA R172K - Registry model: [Cessna R172K](https://openairdocs.org/model/cessna-r172k) (registry code 2072431) (OpenAirDocs) - Category: Airplane - Serial number: R1723062 - Airframe hours: 4916 - Engines: TCM IO-360-KB 210 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Bronson Mark W - Registered owner: Bronson Mark W - Airworthiness certificate: Standard, Normal; Standard, Utility - Last inspection: Annual, July 15, 2008, 12 hours before - Departed: KPAO, Palo Alto, CA - Destination: KPAO, Palo Alto, CA - Airport: KPAO, Palo Alto Airport of Santa Cla ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review February 16, 2008; seat: left; flight hours: 1,418 total, 1,008 in this make and model, 1,163 as pilot in command, 8 in the last 90 days, 2 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: calm - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 50 °F - Altimeter: 30.37 inHg - Observed at: PAO, 4 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 20090109002089A](https://openairdocs.org/incident/20090109002089A), Jan 9, 2009: Cessna R172K, Palo Alto, CA, Substantial damage. (-23) On January 9, 2009 at 2215 pacific standard time, a Cessna R172K, N758FN, made an emergency off field landing shortly following taking off from the Palo… ## Other investigations on N758FN (1) 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. - [NTSB LAX85LA018](https://openairdocs.org/ntsb/LAX85LA018), Oct 15, 1984: Cessna R172 (N758FN), Corning, CA, substantial damage ## Docket (4 files) The files NTSB released with the investigation on November 20, 2009, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73210. 23.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 734 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321459&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - TCM Metallurgical Report (item 2, .PDF, 963 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321460&FileExtension=.PDF&FileName=TCM%20Metallurgical%20Report-Master.PDF - Logbook Excerpts (item 3, .PDF, 22.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321462&FileExtension=.PDF&FileName=Logbook%20Excerpts-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 4, .PDF, 35 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40321461&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-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.