# NTSB CHI97LA204: Grumman-Schweizer G-164B, N6633K, Donnelly, MN, July 7, 1997 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 6, 1997, 20:00 local (Jul 7, 1997, 01:00 UTC) - Place: Donnelly, MN - Coordinates: 45.690174, -96.009902 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.6902&lon=-96.0099&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 2, 1998 - Report: Approved by Office Director - NTSB case key (mKey): 10625 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI97LA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/10625/pdf - Page: https://openairdocs.org/ntsb/CHI97LA204 ## Probable cause undetermined event resulting in the broken connecting rod and cylinder. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - aerial application - engine assembly,connecting rod - fractured (cause) - engine assembly,cylinder - fractured (cause) - reason for occurrence undetermined (cause) - Forced landing, descent - emergency - Nose over, landing ## Analysis The pilot said that he was in a turn to line up on the field he was about to spray when the 'number 9 cylinder blew.' The pilot turned towards a road which he intended to use for landing the airplane on. On approaching the road he 'noticed a person on the road.' The pilot abandoned the attempt to land on that road and began to maneuver for a landing on a perpendicularly intersecting road. As he was maneuvering, the 'engine failed completely.' The pilot put the airplane down in the field. During the landing roll, one main landing gear leg broke. The airplane nosed over coming to rest inverted in the field. Examination of the airplane revealed a large amount of oil covering the airplane's exterior. Examination of the airplane's engine revealed the number nine cylinder broken into three pieces. The number nine cylinder connecting rod was also broken. No other anomalies were found with the airplane. ## Factual narrative On July 6, 1997, at 2000 central daylight time (cdt), a Grumman- Schweizer, G-164B, N6633K, operated by a commercial pilot, sustained substantial damage following a loss of engine power during the aerial application flight. The pilot subsequently force landed the airplane in a field, 3 miles north of Donnelly, Minnesota. During the landing, the airplane nosed over. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was being conducted under 14 CFR Part 137. A flight plan was not on file. The pilot reported no injuries. The local flight originated at Morris, Minnesota, at 1930 cdt. In his written statement, the pilot said that he was in a turn to line up on the field he was about to spray when the "number 9 cylinder blew." The pilot turned towards a road which he intended to use for landing the airplane on. On approaching the road he "noticed a person on the road." The pilot abandoned the attempt to land on that road and began to maneuver for a landing on a perpendicularly intersecting road. As he was maneuvering, the "engine failed completely." The pilot put the airplane down in the field. During the landing roll, one main landing gear leg broke. The airplane nosed over coming to rest inverted in the field. The Federal Aviation Administration (FAA) inspector who examined the airplane said that the right wing had broken off forward of the attach point. The lower wing spar was broken. The vertical stabilizer and rudder were crushed inward and bent over to one side. The engine had broken off of the engine mounts. A large amount of oil was observed on the exterior of the airplane. Examination of the engine revealed the number nine cylinder head broken into three pieces. The number nine cylinder connecting rod was also found broken. Flight control continuity was confirmed. No other anomalies were found with the airplane. ## Aircraft - Registration: [N6633K](https://openairdocs.org/deregistered/N6633K-2025-04-30), registration cancelled 2025-04-30, S/N 400B (OpenAirDocs) - Reported make and model: Grumman-Schweizer G-164B - Registry model: [Grumman Acft ENG Cor-Schweizer G-164B](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164b) (registry code 3952802) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 400B - Engines: P&W R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Registered owner: Kyle J. Scott - Airworthiness certificate: Special, Restricted (Special) - Departed: MOX, MORRIS, MN ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 2,500 total, 1,500 in this make and model, 2,500 as pilot in command, 200 in the last 90 days, 100 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 48 °F - Altimeter: 30.00 inHg - Observed at: MOX, 11 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). - [Incident 19970706021209I](https://openairdocs.org/incident/19970706021209I), Jul 6, 1997: Scwzer G164B, Donnelly, MN, Minor damage. During turn around lost power. Oil on windshield. Hard landing on road. Folded left main gear. Threw rod thru case. (-23) pilot was making turn for spray run &… ## Other investigations on N6633K (3) 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 WPR24LA282](https://openairdocs.org/ntsb/WPR24LA282), Aug 13, 2024: Grumman Acft ENG Cor-Schweizer G-164B (N6633K), Durham, CA, substantial damage. Probable cause: The pilot’s failure to maintain clearance from powerlines, which resulted in a wire strike. - [NTSB CHI99LA215](https://openairdocs.org/ntsb/CHI99LA215), Jul 3, 1999: Grumman-Schweizer G-164B (N6633K), Page, ND, substantial damage. Probable cause: the pilot's failure to compensate for the wind conditions. Factors were the sudden windshift and the crops. - [NTSB LAX91LA301](https://openairdocs.org/ntsb/LAX91LA301), Jul 9, 1991: Grumman G-164B (N6633K), Eloy, AZ, substantial damage. Probable cause: THE FAILURE OF THE PILOT TO MAINTAIN THE TERRAIN CLEARANCE OF THE AIRCRAFT WHILE MANEUVERING FOR A POTENTIAL EMERGENCY LANDING ON A MOONLESS DARK NIGHT. 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.