# NTSB WPR15LA230: Grumman G164 - B, N48452, Princeton, CA, August 4, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 4, 2015, 08:30 local (15:30 UTC) - Place: Princeton, CA - Coordinates: 39.383609, -122.033607 - Nearby events: https://openairdocs.org/map.md?lat=39.3836&lon=-122.0336&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report November 30, 2015 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - ADs cited in the narratives: [AD 99-11-02](https://openairdocs.org/ad/99-11-02) (OpenAirDocs) - NTSB case key (mKey): 91701 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15LA230 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91701/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91701 - Page: https://openairdocs.org/ntsb/WPR15LA230 ## Probable cause The loss of engine power during an agricultural application flight due to a cylinder failure. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 4 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=3952802), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 7 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=3952802), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 2 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=3952802), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 8 cases](https://openairdocs.org/ntsb-events/342/sequence.md?model=3952802), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 19 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=3952802), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, during the agricultural spray run, the engine lost power. The airplane was unable to maintain altitude, so the pilot made a forced landing to a rice field. After touchdown, the airplane nosed over, which resulted in substantial damage to the rudder. A postaccident examination of the engine revealed that the No. 2 cylinder head had cracked and lifted under the cooling fins on the cylinder's left side. The crack continued across the top and inside of the head to the intake valve seat, which would have allowed hot gases to enter the induction system and resulted in the subsequent loss of power. A review of the airplane's maintenance records revealed that a mandatory 100-hour repetitive visual inspection of the cylinder had been performed 66.7 flight hours before the accident flight. ## Factual narrative On August 4, 2015, about 0830 Pacific daylight time, a Grumman G-164B agricultural airplane, N48452, was substantially damaged during a forced landing due to a loss of engine power near Princeton, California. The airplane was operated by Valley Air Service, LTD. The commercial pilot, the sole occupant of the airplane, was not injured. Visual meteorological conditions prevailed for the local aerial application flight, which was being operated in accordance with 14 Code of Federal Regulations Part 137, and a flight plan was not filed. The flight departed Colusa County Airport (O08), about 0800. In a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot reported that the accident occurred on the second load of the morning while applying a fungicide to a rice field. The pilot stated that during a spray run the engine lost power, and unable to maintain altitude, he made a forced landing to the rice field he was treating. The pilot added that the airplane nosed over during the landing, which resulted in substantial damage to the airplane's rudder, and right upper and lower wing panels. On August 18, under the supervision of a Federal Aviation Administration (FAA) Aviation Safety Inspector, the engine was examined by a licensed FAA airframe and powerplant mechanic. The examination revealed that the number 2 cylinder head had cracked and lifted under the cooling fins on the left side of the cylinder. The crack then continued across the top and inside of the head to the intake valve seat, which resulted in the loss of power after the hot gases entered the induction system. The examination revealed no other anomalies with the engine or the airframe that would have precluded normal operation. An examination of the airplane's maintenance records revealed that the most recent annual inspection was performed on March 7, 2015. Records further revealed that on March 16, 2015, FAA Airworthiness Directive (AD) 99-11-02, a mandatory 100-hour repetitive visual inspection to prevent cylinder head cracking, was performed at an engine tachometer time of 3,661.4 hours. At the time of the accident, the engine tachometer read 3,728.1 hours, or 66.7 hours since the AD had been complied with. ## Aircraft - Registration: [N48452](https://openairdocs.org/aircraft/N48452), registered now, S/N 24B, built 1976 (OpenAirDocs) - Reported make and model: GRUMMAN G164 - B (B) - 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: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: 24B - Year built: 1976 - Airframe hours: 16060 - Engines: Pratt & Whitney R-1340 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Valley Air Service LTD - Registered owner: Valley Air Service LTD - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, March 7, 2015, 66 hours before - Departed: O08, Colusa, CA - Destination: O08, Colusa, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 71; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review April 30, 2014; seat: single; restraint: 3-point; flight hours: 13,000 total, 13,000 in this make and model, 13,000 as pilot in command, 100 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 64 °F, dew point 54 °F - Altimeter: 29.94 inHg - Observed at: MYV, 8 nm away ## Docket (6 files) The files NTSB released with the investigation on October 30, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91701. 7.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433352&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Weather Data (item 2, .PDF, 266 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433353&FileExtension=.PDF&FileName=Weather%20Data-Master.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 3, .PDF, 226 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433354&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Master.PDF - FAA Inspector's Report (item 4, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433355&FileExtension=.PDF&FileName=FAA%20Inspector%27s%20Report-Master.PDF - Maintenance Records (item 5, .PDF, 740 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433356&FileExtension=.PDF&FileName=Maintenance%20Records-Master.PDF - FAA Airworthiness Directive 99-11-02 (item 6, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433357&FileExtension=.PDF&FileName=FAA%20Airworthiness%20Directive%2099-11-02-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.