# NTSB CEN23LA326: Robinson Helicopter R44 II, N4174L, Charles City, IA, July 26, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: July 26, 2023, 11:00 local (16:00 UTC) - Place: Charles City, IA - Coordinates: 43.023485, -92.767075 - Nearby events: https://openairdocs.org/map.md?lat=43.0235&lon=-92.7671&mi=10 - Phase of flight: [Prior to flight](https://openairdocs.org/ntsb-phases/100) (OpenAirDocs' grouping) - Defining event: [Prior to flight: Aircraft loading event](https://openairdocs.org/ntsb-events/010) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: Federal Aviation Administration, Des Moines FSDO - NTSB case key (mKey): 192720 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN23LA326 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192720/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192720 - Page: https://openairdocs.org/ntsb/CEN23LA326 ## Probable cause The pilot’s improper preflight of the helicopter to ensure that it was within the loading and performance limitations that resulted in settling and impact with terrain during initial climb. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Planning/preparation: weight/balance calculations](https://openairdocs.org/ntsb-findings/02061015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Robinson Helicopter R44 II, 3 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md?model=7640122), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/02061015/cases.md) - [Aircraft capability: maximum weight](https://openairdocs.org/ntsb-findings/01061035): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [Robinson Helicopter R44 II, 9 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md?model=7640122), [All aircraft, 152 cases](https://openairdocs.org/ntsb-findings/01061035/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft loading event](https://openairdocs.org/ntsb-events/010) (defining event); cases with it: [Robinson Helicopter R44 II, 5 cases](https://openairdocs.org/ntsb-events/010/sequence.md?model=7640122), [All aircraft, 84 cases](https://openairdocs.org/ntsb-events/010/sequence.md) - [Initial climb: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Robinson Helicopter R44 II, 74 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=7640122), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Robinson Helicopter R44 II, 24 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=7640122), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [Robinson Helicopter R44 II, 40 cases](https://openairdocs.org/ntsb-events/092/sequence.md?model=7640122), [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The pilot of the aerial application flight stated that when the flight returned to the load truck, it still had aerial application product aboard, which he was unaware of. He requested and received an additional 60 gallons of product that was loaded onto the helicopter for the accident flight. After loading the helicopter with the additional product, it now was about 172 lbs over the helicopter’s gross weight. When the helicopter departed from the load truck on the accident flight, the helicopter experienced a decay in rotor rpm and settled into an adjacent corn field about 75 ft from the truck. The helicopter sustained substantial damage to the main and tail rotor blades and tail boom. The pilot stated that he was not properly prepared to jettison the load in the event of an emergency and his power cross checks were not adequate. The pilot stated that there was no mechanical malfunction/failure of the helicopter. An excessive load would have reduced the climb performance capability of the helicopter and resulted in settling. ## Aircraft - Registration: [N4174L](https://openairdocs.org/aircraft/N4174L), registered now, S/N 12495, built 2008 (OpenAirDocs) - Reported make and model: ROBINSON HELICOPTER COMPANY R44 II - Registry model: [Robinson Helicopter R44 II](https://openairdocs.org/model/robinson-helicopter-r44-ii) (registry code 7640122) (OpenAirDocs) - Registry engine: [Lycoming IO-540-AE1A5](https://openairdocs.org/engine/lycoming-io-540-ae1a5) (registry code 41899, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: 12495 - Year built: 2008 - Airframe hours: 1913.7 - Engines: Lycoming IO-540 245 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 91 - Operator: Back Nine Aerial LLC, doing business as Recon Helicopters - Registered owner: Cst & Sons LLC - Airworthiness certificate: Special, Restricted (Special) - Departed: West Union, IA - Destination: Charles City, IA - Equipment: ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review April 11, 2022; seat: front; restraint: 4-point; flight hours: 2,057 total, 1,204 in this make and model, 2,032 as pilot in command, 208 in the last 90 days, 189 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 72 °F - Altimeter: 29.82 inHg - Observed at: CCY, 7 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 20230726008029A](https://openairdocs.org/incident/20230726008029A), Jul 26, 2023: Robinson Helicopter Company R44 II, Charles City, IA, Substantial damage. Helicopter returned to tender truck for load of product and fuel. Shortly after departing tender truck helicopter descended into a corn field. ## Docket (3 files) The files NTSB released with the investigation on October 17, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192720. 2.5 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16138784&FileExtension=pdf&FileName=6120%20Master_Redacted-Rel.pdf - Email from pilot 6120.1 form (item 2, PDF, 4 pages, 156 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16138248&FileExtension=pdf&FileName=Re_%20FW_%20NTSB%20Accident%20Report%20Form%206120,%20Robinson%20R44%20N4174L_Redacted-Rel.pdf - Photos (item 3, PDF, 1 page, 265 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16148413&FileExtension=pdf&FileName=Photo%20ver2-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.