# NTSB WPR09LA228: Ayres S2R-T34, N40208, Marysville, CA, May 6, 2009 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: May 5, 2009, 17:41 local (May 6, 2009, 00:41 UTC) - Place: Marysville, CA - Coordinates: 39.097778, -121.569725 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.0978&lon=-121.5697&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining events: [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250); [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250) - Highest injury: Serious injuries - Injuries: 1 serious, 1 uninjured - Status: Completed, report April 22, 2010 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 73781 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR09LA228 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73781/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73781 - Page: https://openairdocs.org/ntsb/WPR09LA228 ## Probable cause (aircraft 2) The failure of both pilots to see and avoid the other airplane while making their final approach for landing. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot (probable cause), aircraft 1; cases with it: [Ayres S2R-T34, 1 case](https://openairdocs.org/ntsb-findings/02021540/cases.md?model=0970106), [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md) - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Ayres S2R-T34, 1 case](https://openairdocs.org/ntsb-findings/02021540/cases.md?model=0970106), [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md) - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot (probable cause), aircraft 2; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02021540/cases.md?model=3952802), [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md) - [Attention/monitoring: monitoring other aircraft](https://openairdocs.org/ntsb-findings/02021540): Personnel issues › Psychological · Pilot of other aircraft (probable cause), aircraft 2; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02021540/cases.md?model=3952802), [All aircraft, 231 cases](https://openairdocs.org/ntsb-findings/02021540/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 1; cases with it: [Ayres S2R-T34, 1 case](https://openairdocs.org/ntsb-events/250/sequence.md?model=0970106), [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md) - [Approach-VFR pattern final: Midair collision](https://openairdocs.org/ntsb-events/250) (defining event), aircraft 2; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-events/250/sequence.md?model=3952802), [All aircraft, 196 cases](https://openairdocs.org/ntsb-events/250/sequence.md) ## Analysis (aircraft 2) An Ayers S2R crop duster entered a left base for the runway at 500-600 feet, then turned left for a 3/4 mile final. At the same time a Grumman G164B entered a long final for the same runway. Neither aircraft had a VHF radio on board and neither pilot had visually acquired the other airplane. As the Grumman crossed the approach end of the runway for landing, the Ayers impacted it from above and behind. Both airplanes crashed entangled onto the runway. ## Factual narrative (aircraft 2) On May 5, 2009, at 1741 Pacific daylight time, a Ayres S2R-T34, N40208, and a Grumman G164B, N6617K, collided while landing on runway 23 at Yuba County Airport, Marysville, California. GN Diddle, Inc., operated the Ayres S2R, and Onstott Dusters operated the Grumman G-164B. Both were operating under the provisions of Title 14 of the Code of Federal Regulations Part 137. The commercial pilot of the Ayres S2R was not injured, and the commercial pilot of the Grumman G-164B was seriously injured. Both airplanes were substantially damaged. Visual meteorological conditions prevailed, and no flight plans had been filed. The pilot of the Ayres S2R stated in his NTSB Pilot Accident Report that he was at 500-600 feet above ground level (agl), entered left base, and then turned on to a 3/4-mile final for runway 23. About 30 feet above the ground he impacted with something underneath him, and the airplane fell to the runway. After the crash he realized that his airplane and another airplane had come together over the runway. At no time, prior to the collision, did he have visual contact with the other airplane. The pilot of the Grumman G-164B stated in his NTSB Pilot Accident Report that he entered a straight in for runway 23, looked for traffic and did not see any. He was over the runway numbers, preparing to land, when he violently lost control of the airplane and hit the ground. As he was being helped out of his airplane he realized his airplane had been struck from behind by another airplane. Yuba County Airport is an uncontrolled airport. Traffic is coordinated between aircraft using a common traffic advisory frequency (CTAF), and pilot visual lookout. Neither airplane was equipped with a VHF radio. ## Aircraft 1 - Registration: [N40208](https://openairdocs.org/deregistered/N40208-2010-04-19), registration cancelled 2010-04-19, S/N T34-023, built 1980 (OpenAirDocs) - Reported make and model: AYRES CORPORATION S2R-T34 - Registry model: [Ayres S2R-T34](https://openairdocs.org/model/ayres-s2r-t34) (registry code 0970106) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PT6A-60A](https://openairdocs.org/engine/pratt-whitney-canada-pt6a-60a) (registry code 52043, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: T34-023 - Airframe hours: 6508 - Engines: P&W CANADA PT6A-60A 1050 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: G N Dibble Inc - Registered owner: G N Dibble Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: 100 hour, April 23, 2009 - Departed: Nicolas, CA - Destination: KMYV, Marysville, CA - Airport: KMYV, Yuba County, runway 23, 6,006 × 150 ft, asphalt ## Aircraft 2 - Registration: [N6617K](https://openairdocs.org/deregistered/N6617K-2018-01-08), registration cancelled 2018-01-08, S/N 392B, built 1978 (OpenAirDocs) - Reported make and model: GRUMMAN ACFT ENG COR-SCHWEIZER 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 R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 392B - Airframe hours: 21133 - Engines: P&W R1340 SERIES 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Onstott Dusters - Registered owner: Vince Crop Dusters Inc - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, April 4, 2009 - Departed: KMYV, Marysville, CA - Destination: KMYV, Marysville, CA - Airport: KMYV, Yuba County, runway 23, 6,006 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N40208; age 47; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review March 20, 2008; seat: single; flight hours: 8,900 total, 3,100 in this make and model, 8,800 as pilot in command, 150 in the last 90 days, 100 in the last 30 days - Pilot, aircraft N6617K; age 62; injuries: serious; commercial; airplane ratings: single-engine land, multi-engine land; medical: class 2, without waivers/limitations; last flight review February 13, 2009; seat: single; flight hours: 36,000 total, 33,000 in this make and model, 36,000 as pilot in command, 180 in the last 90 days, 80 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 12 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 55 °F - Altimeter: 30.01 inHg - Observed at: KMYV ## Docket (2 files) The files NTSB released with the investigation on February 10, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73781. 868 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 501 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325108&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 2, .PDF, 367 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40325109&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.