# NTSB DEN08LA069: Cessna P210N, N4839P, Elizabeth, CO, March 29, 2008 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 29, 2008, 16:54 local (22:54 UTC) - Place: Elizabeth, CO - Coordinates: 39.599998, -104.099998 - Nearby events: https://openairdocs.org/map.md?lat=39.6000&lon=-104.1000&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report December 24, 2008 - Report: Approved by Office Director - Parties: Federal Aviation Administration, Teledyne Continental Motors - NTSB case key (mKey): 67737 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN08LA069 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/67737/pdf - Page: https://openairdocs.org/ntsb/DEN08LA069 ## Probable cause the loss of engine power due to the fatigue failure of the camshaft gear. Contributing to the accident was the lack of suitable terrain for the forced landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip engine power section](https://openairdocs.org/ntsb-findings/01058520): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna P210N, 6 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md?model=2073454), [All aircraft, 233 cases](https://openairdocs.org/ntsb-findings/01058520/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [Cessna P210N, 2 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=2073454), [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. - [Enroute-descent: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Cessna P210N, 20 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=2073454), [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: [Cessna P210N, 16 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073454), [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: [Cessna P210N, 31 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2073454), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis During a normal descent on approach for landing at 8,500 feet mean sea level, the engine "let go/popped into a higher pitch sound, and the power dropped off. [The pilot] checked the fuel flow, tried to get power with the throttle, but no response." During a forced landing, the airplane impacted the side of a gravel road, traveled across the road, struck a ditch, and skidded on the fuselage bottom for approximately 75 feet were it came to rest upright in a residential yard. Examination of the engine exhibited fretting on all six cylinder decks and the main bearing case half sections. The number 2 main bearing support bearing tang lock-slot was found elongated. Various degrees of wear were noted on all crankshaft main bearings, and the number 2 main bearing showed additional wear. The crankshaft number 2 main journal exhibited signatures of thermal discoloration. All oil transfer galleries were free and clear of debris. The camshaft was intact, however, the camshaft gear had a semi-circular section with 7 gear teeth separated, which was found in the gearbox. Metallurgical examination showed the fracture initiated at the surface and progressed in fatigue. The initiation site was damaged; however, the approximate location was identified by crack arrest lines, which encircled the origin. The reason for the fracture initiation could not be determined. ## Factual narrative On March 29, 2008, at 1654 mountain daylight time, a Cessna P210N single-engine airplane, N4839P, sustained substantial damage during a forced landing following a loss of engine power near Elizabeth, Colorado. The commercial pilot and two passengers were not injured. The airplane was registered to Cure Trucking LLC, Bethune, Colorado, and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The flight departed Lamar, Colorado, at 1600, and was en route to Denver, Colorado. Approximately 25 nautical miles southeast of Centennial Airport (APA), Englewood, Colorado, the pilot was instructed by APA air traffic control tower to report a 3 mile final. While descending at 8,500 feet mean sea level (msl), the engine "let go/popped into a higher pitch sound, and the power dropped off. [The pilot] checked the fuel flow, tried to get power with the throttle, but no response." He then attempted a forced landing to a gravel road with the landing gear extended. Subsequently, the airplane impacted the side of the gravel road, traveled across the road, struck a ditch, and skidded on the fuselage bottom for approximately 75 feet where it came to rest upright in a residential yard. Examination of the aircraft showed the fuslage was buckled. A review of the aircraft records revealed the engine underwent a major overhaul on May 7, 1993, at a total engine time of 1,331.0 hours. On July 20, 2007, the engine underwent its most recent 100 hour inspection, at a total time since major overhaul of 1,203.9 hours, and a tachometer time of 2,534.9 hours. On September 9, 2007, at a tachometer time of 2,538.9, the alternator was removed and replaced. At the time of the accident, the engine had accumulated 1,221 hours since major overhaul, and the tachometer time was 2,562.0 hours. On June 3 and 4, 2008, at the facilities of Beegles Aircraft Services, Greeley, Colorado, the engine was examined by a NTSB investigator and a representative of Teledyne Continental Motors (TCM), Mobile, Alabama. Visual examination of the engine and accessories showed that the lower pivot bolt on the alternator was missing, the upper bolt was extruded 3/4 inches, and the alternator belt lacked tension. Safety wire was missing and not secured on several fuel system components. The engine was then disassembled for further examination. Disassembly of the engine showed fretting on all six cylinder decks and the main bearing case half sections. The number 2 main bearing support bearing tang lock-slot was found elongated. Various degrees of wear was noted on all crankshaft main bearings and the number 2 main bearing showed additional wear. The crankshaft number 2 main journal exhibited signatures of thermal discoloration. All oil transfer galleries were free and clear of debris. The camshaft was intact, however, the camshaft gear had a semi-circular section with 7 gear teeth separated, which was found in the gearbox. The camshaft gear and separated section were retained for metallurgical examination. On June 19, 2008, at the TCM metallurgical laboratory, the camshaft gear was examined by a TCM metallurgist and a NTSB investigator. According to TCM, the fracture initiated at the surface and progressed in fatigue from left to right on the gear. The initiation site was damaged; however, the approximate location was identified by crack arrest lines, which encircled the origin. Two gear teeth were removed for additional analysis. The case depth, surface hardness, and core hardness met specifications and no anomalies were noted with the microstructure. The reason for the fracture initiation could not be determined. ## Aircraft - Registration: [N4839P](https://openairdocs.org/deregistered/N4839P-2013-08-22), registration cancelled 2013-08-22, S/N P21000120, built 1978 (OpenAirDocs) - Reported make and model: CESSNA P210N - Registry model: [Cessna P210N](https://openairdocs.org/model/cessna-p210n) (registry code 2073454) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: P21000120 - Airframe hours: 2562 - Engines: Teledyne Continental TSIO-520-P 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Roger L. Millheim - Registered owner: Cure Trucking LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 1, 2007, 17 hours before - Departed: LAA, LAMAR, CO - Destination: APA, DENVER, CO ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review September 1, 2007; seat: left; flight hours: 4,517 total, 1,113 in this make and model, 4,255 as pilot in command, 25 in the last 90 days, 14 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 13 knots, gusting 15 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 61 °F - Altimeter: 29.67 inHg - Observed at: APA, 17 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 20080329013189A](https://openairdocs.org/incident/20080329013189A), Mar 29, 2008: Cessna P210N, Elizabeth, CO, Substantial damage. (-23) Engine lost power and the aircraft landed in a residential area. Preliminary report indicates the engine would not rotate. ## Other investigations on N4839P (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 LAX80FA002](https://openairdocs.org/ntsb/LAX80FA002), Oct 10, 1979: Cessna P210N (N4839P), San Jose, CA, substantial damage 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.