# NTSB CHI95LA032: Cessna 172, N734LJ, Hudson, WI, November 6, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: November 6, 1994, 15:00 local (21:00 UTC) - Place: Hudson, WI - Coordinates: 44.969615, -92.73011 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9696&lon=-92.7301&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report March 27, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9793 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI95LA032 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9793/pdf - Page: https://openairdocs.org/ntsb/CHI95LA032 ## Probable cause inadequate maintenance (major overhaul) by maintenance personnel which resulted in the total loss of engine power. Soft terrain was a related factor. ## 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,valve keeper - improper (contributing factor) - engine assembly,valve,exhaust - loose (contributing factor) - powerplant - seized - maintenance,overhaul,major - inadequate, other maintenance personnel (cause) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - soft (contributing factor) ## Analysis THE PILOT REPORTED HE WAS IN CRUISE FLIGHT AT 2,500 FEET WHEN HE FELT INCREASING VIBRATION IN THE AIRPLANE, THEN THE ENGINE 'FROZE'. THE PILOT WAS UNABLE TO RESTART THE ENGINE AND MADE A FORCED LANDING IN A FRESHLY PLOWED (SOFT) FIELD. THE AIRPLANE NOSED OVER DURING THE LANDING ROLL. POSTACCIDENT ENGINE TEARDOWN REVEALED THE EXHAUST VALVE ON THE #4 CYLINDER HAD LOOSENED AND FALLEN INTO THE CYLINDER. THE AIRPLANE HAD FLOWN 6 HOURS SINCE THE MOST RECENT ANNUAL INSPECTION, AND 77 HOURS SINCE MAJOR OVERHAUL ON THE ENGINE. ## Factual narrative On November 6, 1994, about 1500 central standard time, a Cessna 172, N734LJ, piloted by the private pilot/registered owner, experienced a loss of engine power during cruise flight and made a forced landing in the vicinity of Hudson, Wisconsin. The airplane sustained substantial damage when it nosed over during the landing roll. The pilot and the two passengers on board the airplane reported minor injuries. Visual meteorological conditions prevailed for the local flight, no flight plan was filed. The flight operated under 14 CFR Part 91, and originated from Lake Elmo, Minnesota, approximately 1400. The pilot stated he was in cruise flight at 2,500 feet mean sea level (MSL) when he felt a vibration in the airplane. The vibration increased in intensity until the engine suddenly stopped. The pilot reported he was unable to restart the engine, so he made a forced landing in a freshly plowed field. He stated the terrain was soft and the airplane nosed over during the landing roll. A postaccident engine teardown was conducted. FAA Inspectors reported severe damage to crankcase, valves and cylinders. They stated it appeared the #4 cylinder exhaust valve keeper was displaced and the "...valve caused interference and subsequent engine stoppage." The airplane had flown about 6 hours since the most recent annual inspection, and about 77 hours since major overhaul of the engine. ## Aircraft - Registration: [N734LJ](https://openairdocs.org/aircraft/N734LJ), registered now, S/N 17268935 (OpenAirDocs) - Reported make and model: CESSNA 172 - Registry model: [Cessna 172N](https://openairdocs.org/model/cessna-172n) (registry code 2072434) (OpenAirDocs) - Category: Airplane - Serial number: 17268935 - Airframe hours: 3133 - Engines: LYCOMING O-320-H2AD 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Prawer, William & Boyer, Dean - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 4, 1994, 6 hours before - Departed: 21D, LAKE ELMO, MN - Destination: 21D ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 825 total, 500 in this make and model, 600 as pilot in command, 20 in the last 90 days, 10 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 3 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 50 °F ## 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 19941106040019A](https://openairdocs.org/incident/19941106040019A), Nov 6, 1994: Cessna 172N, St Paul, MN, Substantial damage. Engine failed on local flight. Landed plowed field. Nosed over. Intake valve failed and connecting rod broke. ## Other investigations on N734LJ (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 WPR24LA022](https://openairdocs.org/ntsb/WPR24LA022), Oct 18, 2023: Cessna 172N (N734LJ), Bandera, WA, substantial damage. Probable cause: The pilot’s decision to land at a closed water-soaked grass runway, which resulted in a runway excursion. 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.