# NTSB WPR15LA194: Grumman Acft ENG Cor-Schweizer G 164A, N8598H, Five Points, CA, June 21, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 21, 2015, 06:00 local (13:00 UTC) - Place: Five Points, CA - Coordinates: 36.429721, -120.103057 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.4297&lon=-120.1031&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: Minor injuries - Injuries: 1 minor - Status: Completed, report November 19, 2015 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 91411 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR15LA194 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91411/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91411 - Page: https://openairdocs.org/ntsb/WPR15LA194 ## Probable cause Maintenance personnel’s improper reassembly of the engine during overhaul, which led to the failure of the supercharger-blower due to a lack of lubrication and the subsequent total loss of engine power during takeoff. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng supercharger](https://openairdocs.org/ntsb-findings/01058560): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 3 cases](https://openairdocs.org/ntsb-findings/01058560/cases.md?model=3952801), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/01058560/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 2 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=3952801), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 7 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=3952801), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Takeoff: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 10 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3952801), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 12 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=3952801), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Post-impact: Roll over](https://openairdocs.org/ntsb-events/097); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 2 cases](https://openairdocs.org/ntsb-events/097/sequence.md?model=3952801), [All aircraft, 261 cases](https://openairdocs.org/ntsb-events/097/sequence.md) ## Analysis The pilot reported that, shortly after takeoff for the aerial application flight, the engine lost power. The pilot subsequently initiated a forced landing to a field. The airplane impacted the ground and flipped over. The engine manufacturer's table of limits specified that the minimum side clearance/tolerance between a starter shaft circumference and a starter shaft bushing should be 0.002 inch. However, during postaccident examination, there was no measurable clearance between the starter shaft circumference and the starter shaft bushing, which impeded oil flow to the impeller shaft and bearings and resulted in the failure of the supercharger-blower due to a lack of lubrication. The engine had accumulated 2.0 hours since its last major overhaul, and it is likely that maintenance personnel improperly reassembled the engine during the overhaul. ## Factual narrative On June 21, 2015, about 0600 Pacific daylight time, a Grumman Aircraft ENG COR-Schweizer G 164A, N8598H, sustained substantial damage following a loss of engine power and subsequent emergency landing near Fresno, California. The airplane was registered to, and operated by, Kenny's Crop Dusting, Inc., under the provisions of 14 Code of Federal Regulations (CFR) Part 137 as an aerial application flight. The pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight was departing a private airstrip at the time of the accident. The pilot reported that shortly after takeoff, about 50 feet above ground level, the engine lost power. The pilot initiated a forced landing to a field. The airplane impacted the ground and came to rest inverted. On August 5, 2015, the engine was examined at the facilities of Tulsa Aircraft Engines, Tulsa, Oklahoma. A complete report on the examination is part of the public docket for this accident. The starter drive gear was locked, and unable to rotate by hand inside the blower assembly. The starter drive gear exhibited heat bluing. The starter shaft circumference measured the same dimensions as the starter shaft bushing; there was zero (0) side clearance/tolerance. To lubricate the shaft and the bearings, oil was directed from a hole inside the starter shaft bushing. The Pratt & Whitney R-1340 engine table of limits indicated that the minimum required side clearance/tolerance between the starter shaft and the starter shaft bushing was 0.002 inches. The examination revealed that the engine's blower had failed due to lack of lubrication to the impeller shaft and bearings. At the time of the accident, the engine had accumulated 2.0 hours since its last major overhaul. A review of maintenance records showed that the last major overhaul was dated February 21, 2013, at a total aircraft time of 3,952.76 hours. The engine was installed on the airplane on June 4, 2015. ## Aircraft - Registration: [N8598H](https://openairdocs.org/deregistered/N8598H-2024-06-15), registration cancelled 2024-06-15, S/N 1429, built 1975 (OpenAirDocs) - Reported make and model: GRUMMAN ACFT ENG COR-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) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1429 - Year built: 1975 - Airframe hours: 3952.76 - Engines: Pratt & Whitney R-1340-59 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Kennys Crop Dusting Inc - Registered owner: Kennys Crop Dusting Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, July 7, 2014, 2 hours before - Departed: Five Points, CA - Destination: Five Points, CA - Equipment: Stall warning system, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 62; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review April 15, 2015; seat: center; restraint: 3-point; flight hours: 18,541 total, 18,141 in this make and model, 18,341 as pilot in command, 75 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 39 °F - Altimeter: 29.87 inHg - Observed at: KNLC, 9 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 20150621011339A](https://openairdocs.org/incident/20150621011339A), Jun 21, 2015: Grumman Acft Eng Cor-Schweizer G-164A, Five Points, CA, Substantial damage. Pilot reported engine seized on takeoff. Made emergency landing in plowed field. Aircraft flipped over and came to rest on canopy ## Other investigations on N8598H (4) 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 LAX96LA299](https://openairdocs.org/ntsb/LAX96LA299), Aug 8, 1996: Grumman-Schweizer G-164A (N8598H), Caruthers, CA, substantial damage. Probable cause: the loss of engine power due to the failure of a cylinder. The road's soft surface was a factor. - [NTSB LAX81FVA55](https://openairdocs.org/ntsb/LAX81FVA55), Jul 23, 1981: Grumman G-164A (N8598H), Caruthers, CA, substantial damage - [NTSB OAK78FVA72](https://openairdocs.org/ntsb/OAK78FVA72), Aug 11, 1978: Grumman G-164A (N8598H), Selma, CA, destroyed - [NTSB OAK76DVA91](https://openairdocs.org/ntsb/OAK76DVA91), Sep 22, 1976: Grumman G-164A (N8598H), Easton, CA, substantial damage ## Docket (6 files) The files NTSB released with the investigation on October 22, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91411. 4.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 621 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433067&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - NTSB Engine Examination (item 2, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433068&FileExtension=.PDF&FileName=NTSB%20Engine%20Examination-Master.PDF - Maintenance Record - 100 Hour Inspection (item 3, .PDF, 154 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433069&FileExtension=.PDF&FileName=Maintenance%20Record%20-%20100%20Hour%20Inspection-Master.PDF - Maintenance Record Engine Installation (item 4, .PDF, 132 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433070&FileExtension=.PDF&FileName=Maintenance%20Record%20Engine%20Installation-Master.PDF - Maintenance Record - Overhaul (item 5, .PDF, 148 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433071&FileExtension=.PDF&FileName=Maintenance%20Record%20-%20Overhaul-Master.PDF - Accident Photos (Courtesy of Pilot) (item 6, .PDF, 947 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40433072&FileExtension=.PDF&FileName=Accident%20Photos%20(Courtesy%20of%20Pilot)-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.