# NTSB CHI05CA236: Yamokoski Glastar, N4970Y, Marcellus, MI, August 21, 2005 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 21, 2005, 11:30 local (15:30 UTC) - Place: Marcellus, MI - Coordinates: 42.235, -85.55194 - Nearby events: https://openairdocs.org/map.md?lat=42.2350&lon=-85.5519&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report June 28, 2006 - Report: Approved by Office Director - Parties: South Bend, IN, FSDO - NTSB case key (mKey): 62308 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI05CA236 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/62308/pdf - Page: https://openairdocs.org/ntsb/CHI05CA236 ## Probable cause The in-flight loss of engine power during cruise for undetermined reasons and the unsuitable terrain the pilot encountered during the forced landing. A factor was the tall corn he encountered. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, cruise - reason for occurrence undetermined (cause) - Forced landing, emergency descent/landing - On ground/water encounter with terrain/water, emergency landing - terrain condition - high vegetation (contributing factor) - unsuitable terrain or takeoff/landing/taxi area - encountered, pilot in command (cause) - terrain condition - ground - Nose over, emergency landing ## Analysis The experimental amateur-built airplane sustained substantial damage when the airplane nosed over on impact with high vegetation and terrain during a forced landing following an in-flight loss of engine power. The pilot stated, "At first sign of [decreased] power, turned in direction of nearest airport. Altitude was about [2,800 feet]. Ran fuel selector through all positions; no improvement noted. Determined nearest airport unreachable. Found empty field and directed airplane toward it. Landed short in field [with] tall corn. Aircraft slowed, nose dug in, flipped forward onto its back." An examination of the wreckage did not reveal any pre-impact anomalies. ## Factual narrative On August 21, 2005 about 1130 eastern daylight time, an experimental amateur-built Yamokoski Glastar airplane, N4970Y, sustained substantial damage when the airplane nosed over on impact with high vegetation and terrain during a forced landing following an in-flight loss of engine power near Marcellus, Michigan. The personal flight was operating under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed at the time of the accident. No flight plan was on file. The pilot reported no injuries. The flight originated from the La Porte Municipal Airport, near La Porte, Indiana, about 1100 and was en route to the Mason Jewett Field Airport, Mason, Michigan, at the time of the engine power loss. The pilot's accident report, in part, stated: Noted slight [decrease] in rpm. A minute later, engine began occasional misfire. Engine continued to lose power/rpm, ran increasingly rough until it quit another minute later. At first sign of [decreased] power, turned in direction of nearest airport. Altitude was about [2,800 feet]. Ran fuel selector through all positions; no improvement noted. Determined nearest airport unreachable. Found empty field and directed airplane toward it. Landed short in field [with] tall corn. Aircraft slowed, nose dug in, flipped forward onto its back. A Federal Aviation Administration inspector examined the wreckage. The examination did not reveal any pre-impact anomalies. ## Aircraft - Registration: [N4970Y](https://openairdocs.org/aircraft/N4970Y), registered now, S/N 5377, built 2002 (OpenAirDocs) - Reported make and model: Yamokoski Glastar - Registry model: [Yamokoski William GLASTAR](https://openairdocs.org/model/yamokoski-william-glastar) (registry code 05614QM) (OpenAirDocs) - Registry engine: [Subaru ALL MDLS A/B](https://openairdocs.org/engine/subaru-all-mdls-a-b) (registry code 59050, 4 cycle) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 5377 - Airframe hours: 613 - Engines: Subaru EJ25 165 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: William Yomokoski - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, October 1, 2004, 200 hours before - Departed: PPO, LA PORTE, IN - Destination: TEW, MASON, MI ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; private; airplane ratings: single-engine land; medical: class 3, unknown; last flight review July 1, 2005; seat: left; flight hours: 717 total, 613 in this make and model, 659 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 15 knots, gusting 22 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 57 °F - Altimeter: 30.04 inHg - Observed at: AZO ## 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 20050821024269A](https://openairdocs.org/incident/20050821024269A), Aug 21, 2005: Amtr GLASTAR, Marcellous, MI, Substantial damage. (-23) Pilot stated that aircraft engine started to run rough and quit running at 2800 feet MSL. Pilot landed aircraft in corn field. Aircraft flipped over upon… ## Other investigations on N4970Y (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 CEN12LA470](https://openairdocs.org/ntsb/CEN12LA470), Jul 22, 2012: Yamokoski William Glastar (N4970Y), Chicago, IL, substantial damage. Probable cause: Failure of the automotive engine's reduction gearbox while in cruise flight. 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.