# NTSB CEN11LA563: Grumman Acft ENG Cor-Schweizer G-164A, N127FC, Mansfield, SD, August 10, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 10, 2011, 17:50 local (22:50 UTC) - Place: Mansfield, SD - Coordinates: 45.243331, -98.563331 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.2433&lon=-98.5633&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 27, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA-Rapid City Flight Standards - NTSB case key (mKey): 81455 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11LA563 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81455/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81455 - Page: https://openairdocs.org/ntsb/CEN11LA563 ## Probable cause The loss of engine power due to debris in the engine air intake system. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Power plant: air intake](https://openairdocs.org/ntsb-findings/01057160): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 1 case](https://openairdocs.org/ntsb-findings/01057160/cases.md?model=3952801), [All aircraft, 50 cases](https://openairdocs.org/ntsb-findings/01057160/cases.md) - [Power plant](https://openairdocs.org/ntsb-findings/01057100): Aircraft › Aircraft power plant · Malfunction (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 1 case](https://openairdocs.org/ntsb-findings/01057100/cases.md?model=3952801), [All aircraft, 198 cases](https://openairdocs.org/ntsb-findings/01057100/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 4 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=3952801), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/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) (defining event); 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); 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) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Grumman Acft ENG Cor-Schweizer G-164A, 20 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=3952801), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The engine gradually lost power after takeoff, and the pilot executed a forced landing to a field. The airplane sustained substantial damage to the wings and fuselage. A postaccident examination of the airframe and engine revealed debris in the engine air intake system, which significantly reduced the air available for combustion. The engine was subsequently removed from the airframe and run in a test cell. The test run revealed no anomalies with respect to engine operation. ## Factual narrative On August 10, 2011, about 1750 central daylight time, a Grumman G-164A airplane, N127FC, was substantially damaged during a forced landing following a loss of engine power after takeoff near Mansfield, South Dakota. The pilot was not injured. The agricultural application airplane was registered to and operated by the pilot. The commercial flight was being conducted under the provisions of 14 Code of Federal Regulations Part 137. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The aerial application flight was originating from a private airstrip near Mansfield, South Dakota, at the time of the accident. The pilot reported that the engine began to lose power shortly after takeoff, without sufficient runway remaining to land. The engine gradually lost power completely and he executed a forced landing to a bean field about 1/4 mile from the departure end of the runway. The airplane sustained substantial damage to the wings and fuselage. A postaccident examination revealed debris in the engine air intake system. Debris was found in the carburetor heat section of the intake ducting, which appeared to have nearly blocked the duct completely. Debris was also found on the pressure side of the air filter, which appeared to have blocked about 25-percent of the duct cross section. The agricultural operator noted that the debris appeared to have been composed of paper towels; possibly as a result of rodent activity. The debris was located in an area of the intake ducting not visible during a preflight inspection. The engine was subsequently removed from the airframe and run in a test cell. No components were replaced prior to the test run. The air intake assembly from the airplane was not used because the test cell provided the intake duct work. The engine started without difficulty and ran to 1,500 rpm. The crankshaft appeared to have been bent slightly in the accident, so the engine was not run above 1,500 rpm for safety reasons. The engine was overhauled in March 2011 and installed on the accident airplane in May 2011. At the time of the accident, the engine had accumulated approximately 240 hours since the overhaul. ## Aircraft - Registration: [N127FC](https://openairdocs.org/aircraft/N127FC), registered now, S/N 1393 (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 R-985-AN-1](https://openairdocs.org/engine/pratt-whitney-r-985-an-1) (registry code 51659, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 1393 - Airframe hours: 8451 - Engines: P & W R-985-AN-1 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 25, 2011, 240 hours before - Departed: PVT, Mansfield, SD - Destination: PVT, Mansfield, SD - Airport: PVT, Private ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 50; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; seat: single; flight hours: 10,000 total ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 52 °F - Altimeter: 29.88 inHg - Observed at: ABR, 14 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 20110810023549A](https://openairdocs.org/incident/20110810023549A), Aug 10, 2011: Grumman Acft Eng Cor-Schweizer G-164A, Mansfield, SD, Substantial damage. Pilot [privacy data omitted] took off from a private strip near Mansfield, SD. After take off he lost power and put the aircraft down in a soy bean field, the… ## Docket (6 files) The files NTSB released with the investigation on November 23, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81455. 1.2 MB in all. - Conversation Record -- Pilot (item 1, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357761&FileExtension=.PDF&FileName=Conversation%20Record%20--%20Pilot-Master.PDF - Conversation Record -- Agricultural Service Operator (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357744&FileExtension=.PDF&FileName=Conversation%20Record%20--%20Agricultural%20Service%20Operator-Master.PDF - Correspondence from Agricultural Service Operator (item 3, .PDF, 23 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357747&FileExtension=.PDF&FileName=Correspondence%20from%20Agricultural%20Service%20Operator-Redacted.PDF - Airplane Maintenance Log (item 4, .PDF, 224 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357748&FileExtension=.PDF&FileName=Airplane%20Maintenance%20Log-Redacted.PDF - Engine Maintenance Log (item 5, .PDF, 668 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357750&FileExtension=.PDF&FileName=Engine%20Maintenance%20Log-Redacted.PDF - Sheriff's Office Report (item 6, .PDF, 137 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40357762&FileExtension=.PDF&FileName=Sheriff%27s%20Office%20Report-Redacted.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.