# NTSB CHI97LA097: Piper PA-28-235, N9004W, Des Moines, IA, April 2, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 1, 1997, 18:24 local (Apr 2, 1997, 00:24 UTC) - Place: Des Moines, IA - Coordinates: 41.619483, -93.550834 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.6195&lon=-93.5508&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report September 5, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 10537 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI97LA097 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10537/pdf - Page: https://openairdocs.org/ntsb/CHI97LA097 ## Probable cause oil contamination and starvation due to the inadequate maintenance inspection of the pilot/owner. Factors included the deterioration of the piston pin plug, the connecting rod failure, and the unsuitable terrain for 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 - engine assembly,connecting rod - failure (contributing factor) - engine assembly,bearing - melted (contributing factor) - engine assembly,other - deteriorated (contributing factor) - lubricating system - contamination (cause) - lubricating system - starvation (cause) - maintenance,inspection - inadequate, pilot in command (cause) - Forced landing, emergency descent/landing - Complete gear collapsed, landing - roll - terrain condition - rough/uneven - unsuitable terrain or takeoff/landing/taxi area - selected, pilot in command (contributing factor) ## Analysis The pilot reported that about 40 minutes after takeoff the tachometer started surging. The oil pressure gauge dropped to zero and the engine started knocking. The engine seized and the pilot landed the airplane in a soy bean field. During landing rollout the airplane hit some large ruts which collapsed the landing gear. The engine examination indicated the number six connecting rod had failed and knocked a hole in the top of the crankcase. The number three upper piston pin plug had deteriorated and was contaminating the engine with aluminum metal. The oil filter was opened and evidence of aluminum metal contamination was found. The cam shaft and tappets indicated various stages of spalling. Rust was noted inside all cylinder walls and all the connecting rods had surface rust on them. In addition to the separated number six connecting rod, the number four and five connecting rods were blued and not free to move. The pilot reported that the oil filter was not opened during the oil changes to inspect for metal contamination. The pilot was unaware that the engine oil filter indicated that the oil system was contaminated with metal particles. ## Factual narrative On April 1, 1997, at 1824 central standard time, a Piper PA-28-235, N9004W, sustained substantial damage during a forced landing due to loss of engine power near Des Moines, Iowa. The commercial pilot was not injured. The 14 CFR Part 91 flight departed Morning Star Airport, Des Moines, Iowa, on a local flight. Visual meteorological conditions prevailed and no flight plan had been filed. The pilot reported that he had preflighted the airplane thoroughly before departure. After takeoff he climbed to about 2,500 feet mean sea level (msl) and was at cruise power with the propeller set at 2,300 rpm. About 40 minutes after takeoff, the tachometer went from 2,300 rpm to 2,600 rpm, and then down to 2,200 rpm. The pilot reported that the engine sounded "okay," with no backfiring, mis-firing, or rough running of any kind. He pulled the carburetor heat, checked magnetos, fuel switches, and set the mixture to rich. He reported that he saw the oil pressure gauge read zero about 30 seconds before he made the decision to land in a field for a forced landing. The engine was knocking and it seized before the pilot landed the airplane in a soy bean field. During landing rollout the airplane hit some large ruts which collapsed the landing gear. The engine and engine logbooks were examined. It was determined that the engine was a remanufactured engine that had been installed on the airplane in 1980. The engine had about 600 hours total operating time since being installed on the airplane. The pilot reported that one of the reasons he had purchased the airplane was because the engine was a low time engine. The engine examination revealed that the number six connecting rod had separated and knocked a hole in the top of the crankcase. During the engine teardown, it was determined that the number three upper piston pin plug had been deteriorating and contaminating the engine with aluminum metal. The oil filter was opened and evidence of aluminum metal contamination was found. The oil pressure screen was inspected for contamination and it had some metal particles in the screen. The cam shaft and tappets indicated various stages of spalling, some advanced. Rust was noted inside all cylinder walls and all the connecting rods had surface rust on them. The number six connecting rod was black in color, and the number four and five connecting rods were blued and not free to move. The number five connecting rod bearing was burnished and heat distressed. The pilot reported that the airplane was flown about 75 hours a year. Oil was changed on the airplane about three times a year. The oil filter was not opened during the oil changes to inspect for metal contamination. The pilot reported that he was unaware that the engine oil filter indicated that the oil system was contaminated with metal particles. ## Aircraft - Registration: [N9004W](https://openairdocs.org/deregistered/N9004W-2000-09-16), registration cancelled 2000-09-16, S/N 28-10585 (OpenAirDocs) - Reported make and model: Piper PA-28-235 - Registry model: [Piper PA-28-235](https://openairdocs.org/model/piper-pa-28-235) (registry code 7102810) (OpenAirDocs) - Category: Airplane - Serial number: 28-10585 - Airframe hours: 2321 - Engines: Lycoming O-540 B4B5 235 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: William B. Sevenbergen - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 24, 1996, 70 hours before - Departed: Y76 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 1,568 total, 848 in this make and model, 1,508 as pilot in command, 12 in the last 90 days, 5 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 150° at 11 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 59 °F, dew point 36 °F - Altimeter: 30.00 inHg - Observed at: DSM, 10 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 19970402004089A](https://openairdocs.org/incident/19970402004089A), Apr 2, 1997: Piper PA28235, Johnston, IA, Substantial damage. On departure encountered rough engine. Called approach to advise and landed in bean field. 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.