# NTSB CEN15LA204: Grumman G 164A, N7951, Maysville, OK, April 15, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: April 15, 2015, 11:35 local (16:35 UTC) - Place: Maysville, OK - Coordinates: 34.834167, -97.466667 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.8342&lon=-97.4667&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report April 26, 2016 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - SAIBs cited in the narratives: [SAIB CE-09-35](https://openairdocs.org/saib/CE-09-35) (OpenAirDocs) - NTSB case key (mKey): 91051 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA204 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91051/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91051 - Page: https://openairdocs.org/ntsb/CEN15LA204 ## Probable cause The loss of engine power for reasons that could not be determined because a postaccident examination of the airframe and engine did not reveal any anomalies that would have precluded normal operation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Grumman G-164A, 7 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=3952704), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Unknown or undetermined](https://openairdocs.org/ntsb-events/000) (defining event); cases with it: [Grumman G-164A, 1 case](https://openairdocs.org/ntsb-events/000/sequence.md?model=3952704), [All aircraft, 1,703 cases](https://openairdocs.org/ntsb-events/000/sequence.md) - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Grumman G-164A, 11 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3952704), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Grumman G-164A, 11 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=3952704), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The commercial pilot had completed his second agricultural application flight of the day in the airplane. As he was returning to the departure airport, the engine experienced a loss of power. The pilot conducted a forced landing to a field, and the airplane subsequently nosed over and came to rest inverted. An examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded normal operation. The weather conditions at the time of the accident were conducive to serious icing only at glide power; the engine was likely operating at cruise power at the time of the power loss. The reason for the loss of engine power could not be determined. ## Factual narrative On April 18, 2015, about 1135 central daylight time, a Grumman G-164A airplane, N7951, was substantially damaged during a forced landing following a loss of engine power near Maysville, Oklahoma. The commercial pilot, the sole occupant, sustained minor injuries. The airplane was registered to a private individual and operated by Pro-Ag Service Inc., under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight originated from the Pauls Valley Municipal Airport (PVJ), Pauls Valley, Oklahoma, about 1030.According to initial information obtained by the responding Federal Aviation Administration (FAA) inspector, the pilot had completed his second aerial application of the day and was returning to PVJ when the engine stopped producing power. The pilot performed a forced landing to a field. During the landing, the airplane nosed over resulting in substantial damage to both wings and the vertical stabilizer. An examination of the airframe and engine by the FAA inspector did not find any anomalies which would have precluded normal operation. A review of the carburetor icing probability chart located in Special Airworthiness Information Bulletin CE-09-35 found the airplane was operating in an area conducive only to serious icing only at glide power. ## Aircraft - Registration: [N7951](https://openairdocs.org/deregistered/N7951-2018-10-23), registration cancelled 2018-10-23, S/N 829, built 1971 (OpenAirDocs) - Reported make and model: GRUMMAN G 164A - Registry model: [Grumman G-164A](https://openairdocs.org/model/grumman-g-164a) (registry code 3952704) (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: 829 - Year built: 1971 - Engines: P&W R-985 SERIES 450 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Pro-Ag Service Inc - Registered owner: Putman Jerry L - Airworthiness certificate: Special, Restricted (Special) - Departed: PVJ, PAULS VALLEY, OK - Destination: PVJ, PAULS VALLEY, OK ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; seat: single; flight hours: 9,300 total, 700 in this make and model, 18 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: 2,500 ft broken - Temperature: 70 °F, dew point 59 °F - Altimeter: 29.93 inHg - Observed at: KPVJ, 14 nm away ## Other investigations on N7951 (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 SEA98LA140](https://openairdocs.org/ntsb/SEA98LA140), Jul 17, 1998: Grumman-Schweizer G-164A (N7951), Caldwell, ID, substantial damage. Probable cause: The pilot-in-command's misjudgment of clearance with a power line, resulting in a collision with the line. Factors included a power line and dark night light conditions in the spray area. - [NTSB IAD76FLT13](https://openairdocs.org/ntsb/IAD76FLT13), Jun 21, 1976: Grumman G-164A (N7951), Covington, TN, substantial damage ## Docket (3 files) The files NTSB released with the investigation on March 8, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91051. 616 KB in all. - Correspondence with FAA (item 1, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437452&FileExtension=.PDF&FileName=Correspondence%20with%20FAA-Master.PDF - Carburetor Icing Probability Chart (item 2, .PDF, 313 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437453&FileExtension=.PDF&FileName=Carburetor%20Icing%20Probability%20Chart-Master.PDF - Photos (Courtesy of FAA) (item 3, .PDF, 2 photos, 252 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40437454&FileExtension=.PDF&FileName=Photos%20(Courtesy%20of%20FAA)-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.