# NTSB DEN04LA107: Cessna P210N, N7736K, Douglas, WY, July 20, 2004 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 20, 2004, 16:00 local (22:00 UTC) - Place: Douglas, WY - Coordinates: 42.749061, -105.390792 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.7491&lon=-105.3908&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report July 7, 2005 - Report: Approved by Office Director - Parties: Federal Aviation Administration - NTSB case key (mKey): 59693 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN04LA107 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59693/pdf - Page: https://openairdocs.org/ntsb/DEN04LA107 ## Probable cause the failure of the engine's crankshaft due to the rotation of the engine's number two bearing, which resulted in the oil starvation of the crankshaft's number 2 main journal. Contributing factors include the engine's improper maintenance, and the in-flight collision with a fence post during a forced landing. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - mech failure/malf, cruise - maintenance - improper, other person (contributing factor) - engine assembly,bearing - shifted (contributing factor) - fluid,oil - starvation (contributing factor) - engine assembly,crankshaft - failure (cause) - Forced landing, descent - emergency - In flight collision with object, emergency landing - object - fence post (contributing factor) - In flight collision with terrain/water, emergency landing - terrain condition - open field - terrain condition - grass ## Analysis According to the pilot, while in cruise flight at 22,000 feet msl, the engine "quit." The pilot stated that the propeller continued to "windmill," and at that time he noted approximately 50 gallons of fuel remaining. The pilot's attempts to restart the engine were unsuccessful. He declared an emergency and was diverted to a nearby airport. On final approach to runway 28, the airplane's left main landing gear struck a fence post. The airplane landed approximately 200 feet short of the runway threshold and its left main landing gear collapsed. The airplane veered left of the runway centerline and came to a stop in the grass. The impact buckled the left wing tip and left horizontal stabilizer. An examination of the engine revealed a 7/8-inch by 3/8-inch hole in the top of the crankcase, just forward of the number 1 cylinder. Further examination revealed the engine crankshaft was fractured at the number 2 rod journal. The crankshaft exhibited thermal discoloration and impact marks at the number 2, 3, 4, and 5 rod journals. Rotational scoring and thermal discoloration was observed on the crankshaft's number 2 main bearing. The number 2 bearing was fragmented and fretting was observed on the crankcase halves at the number 2 bearing through bolts. The engine maintenance records indicated on November 17, 2003, at 2,845.0 hours, during the airplane's most recent 100-hour inspection, the number 2 cylinder was replaced. At the time of the accident, the total time was 3,083.0 hours. ## Factual narrative On July 20 2004, at 1600 mountain daylight time, a Cessna P210N, N7736K, operated by a commercial pilot, was substantially damaged during a forced landing at Converse County Airport (DGW), Douglas, Wyoming. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under the provisions of Title 14 CFR Part 91 on an instrument flight rules (IFR) flight plan. The pilot and three passengers were not injured. The flight to Provo, Utah, originated at Rapid City, South Dakota, approximately 1400. According to the pilot, while in cruise flight at 22,000 feet msl, the engine "quit." The pilot stated that the propeller continued to "windmill," and at that time he noted approximately 50 gallons of fuel remaining. The pilot's attempts to restart the engine were unsuccessful. He declared an emergency and was diverted to Douglas. He broke out of the clouds at approximately 14,000 feet agl. On final approach to runway 28, the airplane's left main landing gear struck a fence post and the airplane impacted terrain approximately 200 feet short of the runway threshold. The airplane drifted to the left of the runway centerline and came to a stop in the grass. The impact collapsed the airplane's left main landing gear assembly, and buckled the left wing tip and left horizontal stabilizer. On February 14, 2005, the engine was examined at Teledyne Continental Motors, Inc., in Mobile, Alabama. The examination revealed a 7/8-inch by 3/8-inch hole in the top of the crankcase, just forward of the number 1 cylinder. Further examination revealed that the number 2, 3, 4, 5, and 6 piston rods were fractured. The engine crankshaft was fractured at the number 2 rod journal. The crankshaft exhibited thermal discoloration and impact marks at the number 2, 3, 4, and 5 rod journals. Rotational scoring and thermal discoloration was observed on each main bearing. The crankshaft's number 2 main bearing was fragmented. Fretting was observed on the crankcase halves at the number 2 bearing through bolts. Fretting was also observed on the number 3 and 4 bearing through bolts. According to the airplane's engine maintenance records, on May 31, 2000, at an airframe total time of 2,380.0 hours, a top overhaul was completed on all 6 cylinders. On November 17, 2003, at 2,845.0 hours, during the airplane's most recent 100-hour inspection, the engine's number 2 cylinder was replaced. At the time of the accident, the total airframe time was 3,083.0 hours. ## Aircraft - Registration: [N7736K](https://openairdocs.org/aircraft/N7736K), registered now, S/N P21000420, built 1979 (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: P21000420 - Airframe hours: 3083 - Engines: Continental TSIO520-P6B 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Randy C. Brooks - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 17, 2003, 238 hours before - Departed: RAP, Rapid City, SD - Destination: PVU, Provo, UT - Flight plan: IFR - Airport: DGW, Converse County Airport, runway 28, 6,750 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--no waivers/lim.; last flight review June 14, 2004; seat: left; flight hours: 1,114 total, 281 in this make and model, 1,030 as pilot in command, 74 in the last 90 days, 33 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 110 ft broken - Temperature: 73 °F, dew point 63 °F - Altimeter: 30.06 inHg - Observed at: KDGW ## 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 20040720016069A](https://openairdocs.org/incident/20040720016069A), Jul 20, 2004: Cessna P210N, Douglas, WY, Substantial damage. (-23) While descending from 22,000 feet AGL the engine stopped running due to a broken crankshaft forcing an unplanned landing. ## Other investigations on N7736K (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 ERA21LA159](https://openairdocs.org/ntsb/ERA21LA159), Mar 18, 2021: Cessna 210 (N7736K), Marianna, FL, substantial damage. Probable cause: The failure of the alternator control unit housing plug connection, which resulted in insufficient battery power to fully extend the landing gear. Contributing to the accident was the pilot’s… 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.