# NTSB CHI96LA281: Grumman-Schweizer G-164, N8842H, Grant, NE, August 7, 1996 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 7, 1996, 09:19 local (16:19 UTC) - Place: Grant, NE - Coordinates: 40.840892, -101.720008 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.8409&lon=-101.7200&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 25, 1997 - Report: Approved by Office Director - NTSB case key (mKey): 10348 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI96LA281 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10348/pdf - Page: https://openairdocs.org/ntsb/CHI96LA281 ## Probable cause fatigue failure and subsequent catastrophic failure of the number nine cylinder. A factor was the corn. ## 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, maneuvering - aerial application - engine assembly,cylinder - fatigue (cause) - Forced landing, emergency descent/landing - In flight collision with terrain/water, landing - terrain condition - crop (contributing factor) ## Analysis The pilot reported he was at an altitude of 41 feet, entering his eighth swath run, when the number nine cylinder 'exploded.' The windscreen became covered with oil. He made a shallow turn to avoid a rotary irrigation system and made a forced landing in a corn field. During the forced landing, the left wing impacted the corn and the landing gear 'started sinking into the mud.' The airplane 'spun around' sustaining substantial damage to the lower wings, fuselage, and left wing support struts. Examination of the airplane revealed the number nine cylinder was fractured between the barrel and the head. Evidence of fatigue cracking was evident around the entire circumference of the head. The major fatigue zones accounted for approximately 25 percent of the fracture surface. ## Factual narrative On August 7, 1996, at 0919 mountain standard time, a Grumman-Schweizer G164A, N8842H, operated by Ag-Land, Inc., sustained substantial damage when the right wing impacted corn during a forced landing near Grant, Nebraska. The commercial pilot reported a loss of engine power while he was spraying. He reported no injury. The local aerial application flight originated at 0859 and was conducted under 14 CFR Part 137. Visual meteorological conditions prevailed and no flight plan was filed.The pilot reported he was at an altitude of 41 feet, entering his eighth swath run, when the number nine cylinder "exploded." The windscreen was covered with oil. He made a shallow turn to avoid a rotary irrigation system and conducted a forced landing in a corn field. During the forced landing, the left wing impacted the corn and the landing gear "started sinking into the mud." The airplane "spun around" sustaining substantial damage to the lower wings, fuselage, and left wing support struts. The operator reported that the engine had 894 hours since overhaul. The airplane was examined by a Federal Aviation Administration (FAA) Inspector who reported that the number nine cylinder was fractured between the barrel and the head. He reported no other evidence of preimpact malfunction. The cylinder was examined by a metallurgist at the NTSB laboratory. He reported that "fatigue cracking was evident around the entire circumference of the head... . Two large fatigue zones were visible in the area of the fracture adjacent to the exhaust port... . Both major fatigue zones initiated at multiple origins in a thread root on the inner diameter of the head... . Smaller areas of fatigue progression were visible around the remainder of the cylinder circumference." The major fatigue zones accounted for approximately 25 percent of the fracture surface. Both valves were in place and "appeared undamaged." Combustion deposits were noted on the outboard end face and bevel of the barrel. ## Aircraft - Registration: [N8842H](https://openairdocs.org/deregistered/N8842H-2017-08-28), registration cancelled 2017-08-28, S/N 1537, built 1975 (OpenAirDocs) - Reported make and model: Grumman-Schweizer G-164 - 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: 1537 - Airframe hours: 4571 - Engines: P&W R-985 reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Ag-Land Aviation, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, October 28, 1995, 402 hours before - Departed: GGF ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 37; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 6,473 total, 2,000 in this make and model, 6,246 as pilot in command, 374 in the last 90 days, 192 in the last 30 days, 14 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 270° at 3 knots - Visibility: 7 statute miles - Lowest ceiling: none - Temperature: 79 °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 19960807021379A](https://openairdocs.org/incident/19960807021379A), Aug 7, 1996: Scwzer G164A, Grant, NE, Substantial damage. Aircraft number 9 cylinder head failed during aerial application, made an emergency landing in a corn field. ## Other investigations on N8842H (2) 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 CHI91DCJ03](https://openairdocs.org/ntsb/CHI91DCJ03), Jun 20, 1991: Grumman G-164-A (N8842H), Edgar, NE, substantial damage. Probable cause: THE PILOT'S INADEQUATE AIRCRAFT PREFLIGHT INSPECTION. - [NTSB MKC79DCQ30](https://openairdocs.org/ntsb/MKC79DCQ30), Jun 17, 1979: Grumman G-164A (N8842H), Moscow, KS, destroyed 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.