# NTSB SEA94LA072: Grumman G-164, N6612Q, Walla Walla, WA, March 2, 1994 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 2, 1994, 14:35 local (22:35 UTC) - Place: Walla Walla, WA - Coordinates: 46.110668, -118.29924 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.1107&lon=-118.2992&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report January 26, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 41885 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA94LA072 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41885/pdf - Page: https://openairdocs.org/ntsb/SEA94LA072 ## Probable cause UNSUITABLE TERRAIN FOR A FORCED LANDING AFTER A LOSS OF POWER DUE TO A FAILED ENGINE CYLINDER. FACTORS INCLUDE A PARTIAL MAGNETO FAILURE. ## 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, descent - ignition system,magneto - failure,partial (contributing factor) - engine assembly,cylinder - failure,total (cause) - Forced landing, descent - emergency - Nose over, landing - roll - terrain condition - soft (cause) ## Analysis THE AIRCRAFT DEVELOPED A SEVERE MISS WHILE DESCENDING TO APPLICATION HEIGHT. THE PILOT ATTEMPTED A FORCED LANDING, BUT THE AIRCRAFT NOSED OVER. WHEN THE ENGINE WAS INSPECTED, ONE CYLINDER WAS FOUND SPLIT. THE PILOT STATED THAT HE BELIEVED THAT THE MAGNETO MICARTA GEAR FAILED, CAUSING CROSS-FIRING, BLOWING THE DOOR OFF THE AIR CLEANER AND SPLITTING A CYLINDER. ## Factual narrative On March 2, 1994, approximately 1435 Pacific standard time, a Grumman G-164, N6612Q, nosed over and sustained substantial damage after a loss of power while in a descent, eight miles southwest of Walla Walla, Washington. The commercial pilot, who was uninjured, was conducting aerial application operations under 14CFR137. There was no fire, and no ELT was installed in the aircraft. The pilot stated that while on descent, the aircraft lost power, and he attempted a forced landing, but the aircraft nosed over during rollout from the landing, due to soft ground. He stated that he was on his sixth load of the day, and the second flying day of the season. When the engine was inspected it was determined that an engine cylinder had split. The pilot/operator believed that a magneto micarta gear had failed, resulting in the engine cross firing, blowing the door off the air cleaner when it backfired and splitting the cylinder. ## Aircraft - Registration: [N6612Q](https://openairdocs.org/aircraft/N6612Q), registered now, S/N 163B (OpenAirDocs) - Reported make and model: GRUMMAN G-164 - Registry model: [Grumman Acft ENG Cor-Schweizer G-164B](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164b) (registry code 3952802) (OpenAirDocs) - Category: Airplane - Serial number: 163B - Airframe hours: 4840 - Engines: P&W R-1340-AN1 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Blue Mountain Aviation - Registered owner: Blue Mountain Aviation - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, January 3, 1994, 7 hours before ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 2,690 total, 1,200 in this make and model, 2,630 as pilot in command, 12 in the last 90 days, 6 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 20 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 63 °F, dew point 46 °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 19940302003459A](https://openairdocs.org/incident/19940302003459A), Mar 2, 1994: Scwzer G164, Walla Walla, WA, Substantial damage. Lost power descending for spray run nosed over landing. Mag micarta gear broke caused cross firing. Split cylinder. ## Other investigations on N6612Q (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 WPR24LA151](https://openairdocs.org/ntsb/WPR24LA151), May 12, 2024: Grumman G164 (N6612Q), Maxwell, CA, destroyed. Probable cause: The pilot’s failure to ascertain a proper touchdown point and late decision to initiate a go-around, which resulted in a subsequent collision with vegetation. - [NTSB LAX78DUJ28](https://openairdocs.org/ntsb/LAX78DUJ28), Feb 12, 1978: Grumman G-164B (N6612Q), Coolidge, AZ, 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.