# NTSB CEN20LA276: Rockwell S2R R1340, N3104S, Keokuk, IA, July 12, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 12, 2020, 11:10 local (16:10 UTC) - Place: Keokuk, IA - Coordinates: 40.442779, -91.424163 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.4428&lon=-91.4242&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Fuel related](https://openairdocs.org/ntsb-events/190) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA FSDO - NTSB case key (mKey): 101583 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN20LA276 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101583/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101583 - Page: https://openairdocs.org/ntsb/CEN20LA276 ## Probable cause The improper installation of a fuel vent line during maintenance, which resulted in fuel starvation and a total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Ayres S2R-R1340, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=0970210), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Ayres S2R-R1340, 1 case](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=0970210), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Fuel related](https://openairdocs.org/ntsb-events/190) (defining event); cases with it: [Ayres S2R-R1340, 1 case](https://openairdocs.org/ntsb-events/190/sequence.md?model=0970210), [All aircraft, 361 cases](https://openairdocs.org/ntsb-events/190/sequence.md) - [Approach: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341); cases with it: [Ayres S2R-R1340, 1 case](https://openairdocs.org/ntsb-events/341/sequence.md?model=0970210), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) ## Analysis The agricultural airplane was on final approach to a planned fuel stop during the cross-country flight when the accident occurred. About 3-4 miles from the airport, the engine temperature surged then decreased. The engine stopped running and the pilot decided to land in a field, resulting in substantial damage to the right wing. Examination of the airplane revealed a kinked rubber fuel vent line in the right wing. The line was creased across a structural beam, which restricted the air flow to the fuel tank. Just before the accident flight, the airplane was at a maintenance facility for repairs. During the repairs, the wings had been removed and replaced. The right wing’s fuel vent line was not installed properly. This most likely resulted in an air blockage and drop in fuel pressure as the fuel quantity was reduced during the 2.5-hour flight, resulting in the loss of engine power. ## Factual narrative On July 12, 2020, about 1110 central daylight time, a Rockwell Thrush S2R R1340, N3104S, was substantially damaged when it was involved in an accident near Keokuk, Iowa. The commercial pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 ferry flight. The agricultural airplane had just completed repairs at a certified repair facility. Part of the repairs included the removal and reinstallation of both wings. The intent of the flight was to ferry the airplane cross-country from the repair station to its home base in Vinton, Iowa. A planned fuel stop was at the Keokuk Municipal Airport (EOK), Keokuk, Iowa. According to the pilot, he had topped off the airplane with 197 gallons of fuel before departing the repair station. The pilot set up on a straight-in approach to at EOK and was flying about 1,500 -1,800 ft above ground level when the engine temperature surged then decreased. The engine stopped running and the pilot attempted restart procedures. The pilot determined that he was not going to make it to the airport so he decided to land the airplane in a field. During the landing, the airplane sustained substantial damage to the right wing. Examination of the airplane after the accident revealed that a rubber fuel vent line in the right wing was bent across a structural beam kinking the line in a manner that would restrict the airflow through the line. The creased fuel vent was not related to impact damage. The installation of the right wing's vent line was improper. ## Aircraft - Registration: [N3104S](https://openairdocs.org/deregistered/N3104S-2022-06-04), registration cancelled 2022-06-04, S/N R1340-025, built 1990 (OpenAirDocs) - Reported make and model: Rockwell S2R R1340 (No Series) - Registry model: [Ayres S2R-R1340](https://openairdocs.org/model/ayres-s2r-r1340) (registry code 0970210) (OpenAirDocs) - Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: R1340-025 - Year built: 1990 - Engines: Garrett TPE331-6 650 horsepower turbo prop - Damage: Substantial damage - Flight: Ferry, Part 91 - Operator: Wayson Air - Registered owner: Wayson Air - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, July 11, 2020, 7,157 hours before - Departed: M28, Hayti, MO - Destination: VTI, Vinton, IA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 21; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; seat: center; restraint: 5-point; flight hours: 2,500 total, 300 in this make and model, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 360° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 63 °F - Altimeter: 29.93 inHg - Observed at: EOK, 50 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 20200712016229A](https://openairdocs.org/incident/20200712016229A), Jul 12, 2020: Ayres Corporation S2R-R1340, Keokuk, IA, Substantial damage. On 07/12/2020 Ayres thrush S2R N3104S was flying from hayti, Missouri to vinton, Iowa the aircraft was full of fuel prior to departure. During the decent into… ## Other investigations on N3104S (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 CEN11CA301](https://openairdocs.org/ntsb/CEN11CA301), Apr 25, 2011: Ayres S2R-R1340 (N3104S), Estelline, SD, substantial damage. Probable cause: The pilot's failure to maintain directional control of the airplane during takeoff. - [NTSB FTW04LA159](https://openairdocs.org/ntsb/FTW04LA159), Jun 11, 2004: Ayres S-2R (N3104S), Eagle Lake, TX, substantial damage. Probable cause: The partial collapse of the left main landing gear as a result of a failure of the fuselage structure due to corrosion. ## Docket (3 files) The files NTSB released with the investigation on June 29, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101583. 1.3 MB in all. - Memorandum for the record pilot statement summary CEN20LA276 (item 1, PDF, 1 page, 132 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14004811&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Pilot%20Statement%20Summary%20CEN20LA276_Redacted-Rel.pdf - Memorandum for the record wreckage examination findings CEN20LA276 (item 2, PDF, 1 page, 157 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14004933&FileExtension=pdf&FileName=Memorandum%20for%20the%20Record%20Wreckage%20Examination%20Findings%20CEN20LA276_Redacted-Rel.pdf - Photo array CEN20LA276 (item 3, PDF, 1 page, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14005092&FileExtension=pdf&FileName=Photo%20Array%20CEN20LA276-Rel.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.