# NTSB ATL98LA055: Grumman-Schweizer G-164A, N8626H, Marianna, FL, March 14, 1998 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 14, 1998, 09:10 local (15:10 UTC) - Place: Marianna, FL - Coordinates: 30.850915, -85.230812 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.8509&lon=-85.2308&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report February 15, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 3978 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL98LA055 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/3978/pdf - Page: https://openairdocs.org/ntsb/ATL98LA055 ## Probable cause The failure of maintenance personnel to secure the magneto cover that resulted in water contamination and the subsequent loss of engine power. A factor was rough and uneven terrain. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power, maneuvering - aerial application - ignition system,magneto - contamination,water (cause) - ignition system,magneto - open (cause) - maintenance - inadequate, other maintenance personnel (cause) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - rough/uneven (contributing factor) ## Analysis Approximately ten minutes into the flight the pilot reported that the engine developed a rough running condition. The pilot tried several power settings in an effort to reduce the condition, but no action on his part resolved the rough running condition. Since the pilot could not maintain altitude, the he selected an adjacent field for an emergency landing. The pilot said that landing surface was rough and uneven. Examination of the engine assembly disclosed that the right magneto cover was not secure and that the five screws that secure the cover to the magneto assembly were missing. The visual examination of the internal components of the magneto assembly showed evidence of water stains on the magneto block. Internal component continuity was established when the engine was rotated completely through. Low compression was also noted on all cylinders. ## Factual narrative On March 14, 1998, at 0910 central standard time, a Grumman-Schweizer G-164A, N8626H, nosed over, according to the pilot, during a full stop landing on a county road near Marianna Florida. The aerial application flight operated under the provisions of 14 CFR Part 137 with no flight plan filed. The pilot reported that visual weather conditions prevailed at the time of the accident. The commercial rated pilot received minor injuries. According to the pilot, the airplane sustained substantial structural damage. The flight departed the staging area near Marianna, Florida, at 0905. Approximately five minutes into the flight the pilot reported that the engine developed a rough running condition. The pilot tried several power settings in an effort to reduce the condition, but no action on his part resolved the rough running condition. Since the pilot could not maintain altitude, he then selected an adjacent field for an emergency landing. The pilot said that landing surface was rough and uneven. Examination of the engine assembly disclosed that the right magneto cover was not secure and that the five screws that secure the cover to the magneto assembly were missing. The visual examination of the internal components of the magneto assembly showed evidence of water stains on the magneto block. Internal component continuity was established when the engine was rotated completely through. Low compression was also noted on all cylinders. A small quantity of fuel was recovered from the carburetor. According to the aircraft wreckage recovery crew, a substantial amount of fuel was recovered from the wing tanks at the accident site. ## Aircraft - Registration: [N8626H](https://openairdocs.org/deregistered/N8626H-2000-01-05), registration cancelled 2000-01-05, S/N 1437 (OpenAirDocs) - Reported make and model: Grumman-Schweizer 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) - Category: Airplane - Serial number: 1437 - Airframe hours: 7737 - Engines: P&W R-985-AN14B 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Steve Odom - Registered owner: Judy Yon - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, August 12, 1997, 66 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 6,176 total, 1,535 in this make and model, 5,791 as pilot in command, 30 in the last 90 days, 30 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 260° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 52 °F, dew point 39 °F - Altimeter: 30.00 inHg - Observed at: MAI, 1 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). - [Accident 19980314003469A](https://openairdocs.org/incident/19980314003469A), Mar 14, 1998: Scwzer G164A, Marianna, FL, Substantial damage. Approximately ten minutes into the flight the pilot reported that the engine developed a rough running condition. The pilot tried suveral power settings in an… 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.