# NTSB SEA04LA139: Grumman G-164A, N7220, Nyssa, OR, July 23, 2004 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: July 22, 2004, 20:30 local (Jul 23, 2004, 02:30 UTC) - Place: Nyssa, OR - Coordinates: 43.886943, -117.08361 - Nearby events: https://openairdocs.org/map.md?lat=43.8869&lon=-117.0836&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report January 24, 2005 - Report: Approved by Office Director - Parties: Boise FSDO - NTSB case key (mKey): 59712 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA04LA139 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/59712/pdf - Page: https://openairdocs.org/ntsb/SEA04LA139 ## Probable cause The failure (fracture) of the number four cylinder head during an aerial application run. Factors include the soft crop-covered terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, maneuvering - aerial application - engine assembly,cylinder - fractured (cause) - Forced landing, descent - emergency - On ground/water encounter with terrain/water, emergency landing - Gear collapsed, landing - roll - terrain condition - crop (contributing factor) - terrain condition - soft (contributing factor) - landing gear,main gear strut - overload - Nose over, landing - roll ## Analysis During an aerial application run, the pilot heard a loud bang, and the engine suddenly lost a significant amount of power. Because the aircraft did not have enough power to remain airborne, the pilot elected to execute a forced landing in a nearby agricultural field. Although the initial touchdown was uneventful, the main gear of the aircraft dug into the soft terrain, leading to a main gear collapse and a nose-over of the aircraft. It was ultimately determined that while the aircraft was in flight, the number four cylinder head had fractured near where the cylinder head was screwed into the cylinder barrel, and the fracture was of such a nature that it kept the cylinder from developing the compression necessary for detonation of the fuel/air mixture. ## Factual narrative On July 22, 2004, approximately 2030 mountain daylight time, a Grumman G-164A, nosed over after experiencing a main landing gear collapse during a forced landing in an agricultural field about two miles west of Nyssa, Idaho. The commercial pilot, who was the sole occupant, received minor injuries, and the aircraft, which was owned and operated by the pilot, sustained substantial damage. The 14 CFR Part 137 aerial application flight, which departed a local agricultural airfield, had been airborne for about 10 minutes at the time of the accident. The flight was taking place in visual meteorological conditions. No flight plan had been filed. According to the pilot, during one of his application runs there was a loud bang, and the engine suddenly lost a significant amount of power. Since it appeared that he did not have enough power to remain airborne, he elected to execute a forced landing in a nearby agricultural field. Although the initial touchdown was uneventful, the main gear of the aircraft dug into the soft terrain, leading to a main gear collapse and a nose-over of the aircraft. According to both the pilot and the FAA Inspector who responded to the accident, it was determined that while the aircraft was in flight, the number four cylinder head had fractured near where the cylinder head was screwed into the cylinder barrel. The FAA Inspector said that the fracture was of such a nature that it kept the cylinder from developing the compression necessary for detonation of the fuel/air mixture. ## Aircraft - Registration: [N7220](https://openairdocs.org/aircraft/N7220), registered now, S/N 896, built 1972 (OpenAirDocs) - Reported make and model: Grumman G-164A - Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 896 - Engines: Pratt & Whitney R-985 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Donald L. Taylor, doing business as Don Taylor Aviation - Registered owner: Mid Contineint Aircraft - Airworthiness certificate: Special, Restricted (Special) - Departed: Nyssa, ID ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: minor; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: rear; flight hours: 26,025 total, 150 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 10 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 90 °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 20040722017889A](https://openairdocs.org/incident/20040722017889A), Jul 22, 2004: Scwzer G164A, Vale, OR, Substantial damage. (-23) Number four cylinders came apart during spraying operations. Aircraft lost power. Pilot landed in a soft field and the aircraft flipped over onto its… 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.