# NTSB WPR09LA227: Grumman G-164B, N6628Q, Colfax, WA, May 4, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 4, 2009, 16:20 local (23:20 UTC) - Place: Colfax, WA - Coordinates: 46.858612, -117.414169 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=46.8586&lon=-117.4142&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report May 19, 2011 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration Spokane FSDO - NTSB case key (mKey): 73773 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA227 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73773/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73773 - Page: https://openairdocs.org/ntsb/WPR09LA227 ## Probable cause A total loss of engine power due to excessive wear in several carburetor components that led to a malfunction of the carburetor. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 2 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=3952802), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) - [Terrain: wet/muddy terrain](https://openairdocs.org/ntsb-findings/03021035): Environmental issues › Physical environment · Effect on equipment; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 4 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md?model=3952802), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md) - [Engine fuel and control: fuel control/carburetor](https://openairdocs.org/ntsb-findings/01057322): Aircraft › Aircraft power plant · Fatigue/wear/corrosion (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 2 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md?model=3952802), [All aircraft, 195 cases](https://openairdocs.org/ntsb-findings/01057322/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 13 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3952802), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-flare/touchdown: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 17 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=3952802), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis The pilot stated that the airplane was about 100 feet above ground level following takeoff when the engine lost power. He landed straight ahead in a muddy dirt field. During the landing roll, the airplane nosed over and the engine separated from the airframe. Postaccident examination of the engine core revealed no anomalies that would have precluded normal operation. Examination of the carburetor revealed that the bushings on the throttle shaft and pump stem were worn, which allowed excessive play. The economizer linkage was also found to be loose; there was evidence of fretting on the mating surface to the engine and around the mounting bolt holes. The carburetor fuel screen was clean. The floats exhibited hydraulic crush damage consistent with fuel in the bowl, and the accelerator pump was worn. Based on the findings of the postaccident examination, excessive wear of the carburetor likely led to the loss of engine power. ## Factual narrative On May 4, 2009, about 1620 Pacific daylight time, a Grumman G-164B, N6628Q, collided with terrain during a forced landing at Colfax, Washington. The owner was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 133. The certificated commercial pilot was not injured. The airplane sustained substantial damage to the firewall, fuselage, and empennage by impact forces. The local aerial application flight was departing when the accident occurred. Visual meteorological conditions prevailed, and no flight plan had been filed. The operator reported that the accident flight was the 14th flight of the day. The pilot fueled the airplane prior to the 13th flight. The pilot stated that the airplane was about 100 feet above ground level following takeoff when the engine lost power. The pilot landed straight ahead in a muddy dirt field. During the landing roll, the airplane nosed over, and the engine separated from the airframe. Gustin Aviation, Lewiston, Idaho, examined the engine under the supervision of a Federal Aviation Administration (FAA) inspector. Examination notes are in the public docket. Pertinent parts of the examination follow. The engine was not runable. Technicians placed it on a stand, and removed the spark plugs. Gaps for all spark plugs were similar with no mechanical deformation. The electrodes for the front spark plugs were oval. Electrodes for the front plugs for cylinders 2, 3, and 6 were gray, which corresponded to normal operation according to the Champion Aviation Check-A-Plug AV-27 Chart. Electrodes for the front plugs for cylinders 1, 4, 5, 7, 8, and 9 were black and sooty, which corresponded to excessive ground idle time or rich idle mixture when compared to the AV-27 chart. Electrodes for the back plugs for cylinders 2, 3, 7, 8, and 9 were gray; 2 and 7 had hard, cylinder like deposits, which indicated lead fouling per the AV-27 chart. Electrodes for the back plugs or cylinders 1 and 4 were black and sooty. Electrodes for the back plugs for cylinders 5 and 6 were wet and oily. Technicians manually rotated the crankshaft with a wrench. The crankshaft rotated freely, and the valves moved approximately the same amount of lift in firing order. The oil sump screen and oil filter were free of debris. The FAA inspector stated that he noted no anomalies during the engine examination that would have precluded normal operation. The Safety Board investigator-in-charge (IIC) oversaw examination of the Stromberg carburetor (part number nay9e1, serial number 5966358), at S&T Aircraft Accessories in New Braunfels, Texas. It sustained substantial crush damage. Technicians pointed out that the bushings on the throttle shaft were worn, and there was excessive play. The pump stem bushing was worn, and there was excessive play. The economizer linkage was loose. There were fretting signatures on the mating surface to the engine, and fretting on the mounting bolt holes. The carburetor fuel screen was clean. Thefloats exhibited crush damage, and the accelerator pump was worn. Following the initial engine examination and release of wreckage, it was sent to Covington Aircraft, Covington, Oklahoma, for a propeller strike inspection. The engine was repaired and returned to the owner who installed it on the airplane. Following a test flight, the owner reported that it was running rough, and he returned the engine to Covington for further examination. They reported that they found a defective exhaust camshaft lobe, and replaced it, which remedied the engine roughness. Covington reported that a defective camshaft lobe could cause roughness, and if ignored, could lead to multiple lobe failure and a loss of engine power. However, they noted that this lobe was not defective to that point, and would not have been a cause for the reported loss of power. They felt that the carburetor was the reason for the loss of engine power. ## Aircraft - Registration: [N6628Q](https://openairdocs.org/aircraft/N6628Q), registered now, S/N 154B, built 1976 (OpenAirDocs) - Reported make and model: GRUMMAN 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 R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 154B - Airframe hours: 9447 - Engines: Pratt & Whitney R1340-AN2 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Darrell L Fender - Registered owner: Darrell L Fender - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, January 15, 2009, 116 hours before - Departed: S94, Colfax, WA - Destination: S94, Colfax, WA - Airport: S94, Colfax, runway 07, 3,200 × 60 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 36; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review March 27, 2009; seat: single; flight hours: 1,170 total, 503 in this make and model, 979 as pilot in command, 119 in the last 90 days, 65 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 13 knots - Visibility: 10 statute miles - Lowest ceiling: 10,000 ft broken - Temperature: 59 °F, dew point 34 °F - Altimeter: 29.75 inHg - Observed at: KPUW, 16 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 20090504006449A](https://openairdocs.org/incident/20090504006449A), May 4, 2009: Scwzer G164B, Colfax, WA, Substantial damage. (-23) Aircraft collided with the terrain following takeoff from runway 7 at Colfax, was airport (S94). The owner was operating the airplane under the… ## Other investigations on N6628Q (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 WPR11LA384](https://openairdocs.org/ntsb/WPR11LA384), Aug 15, 2011: Grumman Acft ENG Cor-Schweizer G-164B (N6628Q), Oakesdale, WA, substantial damage. Probable cause: The pilot's decision to land with a high tailwind, which resulted in a nose-over. - [NTSB LAX91LA299](https://openairdocs.org/ntsb/LAX91LA299), Jul 9, 1991: Grumman G-164B (N6628Q), Crows Landing, CA, destroyed. Probable cause: THE PILOT LANDING HIS AIRPLANE ERRONEOUSLY ON THE WRONG LANDING SURFACE. FACTORS IN THIS ACCIDENT WERE: SUNGLARE AND ITS INTERFERENCE WITH THE PILOT'S VISION AND THE SOFT TERRAIN. - [NTSB LAX83LA009](https://openairdocs.org/ntsb/LAX83LA009), Oct 26, 1982: Grumman G-164B (N6628Q), Coolidge, AZ, substantial damage ## Docket (4 files) The files NTSB released with the investigation on March 15, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73773. 4.9 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344764&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation with FAA Inspector on Engine Exam Findings (item 2, .PDF, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342807&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20FAA%20Inspector%20on%20Engine%20Exam%20Findings-Master.PDF - NTSB Carburetor Exam Notes with 2 Embedded Photos (item 3, .PDF, 931 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40344762&FileExtension=.PDF&FileName=NTSB%20Carburetor%20Exam%20Notes%20with%202%20Embedded%20Photos-Master.PDF - Covington Engine Examination Findings (item 4, .PDF, 47 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40342809&FileExtension=.PDF&FileName=Covington%20Engine%20Examination%20Findings-Master.PDF 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.