# NTSB WPR21LA350: Cessna 404, N5409G, Sheridan, WY, September 18, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: September 18, 2021, 07:50 local (13:50 UTC) - Place: Sheridan, WY · Side of runway - Coordinates: 44.774496, -106.98766 - Nearby events: https://openairdocs.org/map.md?lat=44.7745&lon=-106.9877&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Medical event](https://openairdocs.org/ntsb-events/850) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: FAA FSDO - NTSB case key (mKey): 103932 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR21LA350 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103932/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103932 - Page: https://openairdocs.org/ntsb/WPR21LA350 ## Probable cause The pilot experiencing an episode of impaired behavior and incapacitation for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Impairment/incapacitation: other loss of consciousness](https://openairdocs.org/ntsb-findings/02012055): Personnel issues › Physical · Pilot (probable cause); cases with it: [Cessna 404, 1 case](https://openairdocs.org/ntsb-findings/02012055/cases.md?model=2075901), [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/02012055/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 404, 3 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2075901), [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. - [Landing-flare/touchdown: Medical event](https://openairdocs.org/ntsb-events/850) (defining event); cases with it: [Cessna 404, 1 case](https://openairdocs.org/ntsb-events/850/sequence.md?model=2075901), [All aircraft, 63 cases](https://openairdocs.org/ntsb-events/850/sequence.md) ## Analysis The pilot stated that the flight and landing approach were uneventful. He recalled configuring the airplane for landing by extending the landing gear and flaps then began the landing flare. His next recollection was of being in the airplane at the right side of the runway surrounded by a cloud of dust. He did not have any recollection of how the airplane got there. Examination of the airplane found the landing gear had collapsed; the nose structure was deformed. While the exact cause of the pilot’s behavior change could not be determined from the available evidence, it is likely he was impaired by a medical event during landing and then possibly incapacitated for a short time. A number of possibilities could explain this event, none of which would have left any direct evidence and all of which could have caused a period of unconsciousness or amnesia. Although he was diagnosed with COVID-19 following the accident, symptoms would have been unlikely to suddenly severely impair the pilot and his memory but allow him to fully recover within a few minutes. ## Factual narrative On September 18, 2021, about 0750, a Cessna 404, N5409G, was substantially damaged when it was involved in an accident near Sheridan, Wyoming. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 135 scheduled cargo flight. The pilot stated that he loaded the airplane, along with help from ground handlers, and that there were no HAZMAT packages presented during loading. The total weight of cargo was 154 lbs, and it was loaded behind a net in the aft cargo area. He stated that the flight and landing approach were uneventful, and he recalled configuring the airplane for landing by extending the landing gear and flaps. He began the landing flare, but his next recollection was of being in the airplane at the right side of the runway surrounded by a cloud of dust. He did not have any recollection of how the airplane got there. Examination of the airplane revealed that it had departed runway 15 shortly after landing. The landing gear had collapsed, the nose structure was deformed, and the runway surface exhibited a set of gouges that matched the dimensions of the right wheel rim, and two sets of slash marks consistent with propeller strike. The pilot refused emergency medical treatment at the accident scene, and visited his personal physician three days later, complaining of back and neck pain following the accident. During that visit, his vital signs, including his pulse oximetry, were normal. The pilot recounted the accident circumstances to the physician and was concerned about why he couldn’t remember the events. The medical record stated, “He does not believe he lost consciousness but is unclear.” The physical examination was unremarkable. The physician obtained a chest X-ray, which showed patchy infiltrates, and the pilot tested positive for COVID-19 the following day. He had blood tests that were normal and a brain MRI on October 11, 2021, did not reveal any acute findings. The pilot had reported remote surgeries and seasonal allergies to the FAA at his last medical examination without any use of medications. According to personal medical records, in February 2021, he reported having gastroesophageal reflux disease and using omeprazole to treat it. ## Aircraft - Registration: [N5409G](https://openairdocs.org/aircraft/N5409G), registered now, S/N 404-0028 (OpenAirDocs) - Reported make and model: CESSNA 404 - Registry model: [Cessna 404](https://openairdocs.org/model/cessna-404) (registry code 2075901) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 404-0028 - Year built: 1977 - Airframe hours: 27377 - Engines: CONT MOTOR TSIO-520 SER 375 horsepower reciprocating; CONT MOTOR TSIO-520 SER 375 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 135 - Operator: Richland Aviation Inc, doing business as Richland Aviation - Registered owner: Richland Aviation Inc - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, August 30, 2021, 23 hours before - Departed: BIL, Billings, MT - Destination: Same as departure - Flight plan: VFR - Airport: SHR, Sheridan County, runway 15/33, 8,301 × 100 ft, asphalt - Equipment: ADS-B, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 20, 2021; seat: left; restraint: 3-point; flight hours: 12,859 total, 3,217 in this make and model, 12,742 as pilot in command, 92 in the last 90 days, 40 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 57 °F, dew point 34 °F - Altimeter: 29.92 inHg - Observed at: KSHR, 1 nm away - METAR: METAR KSHR 181353Z AUTO 00000KT 10SM CLR 14/01 A2992 RMK AO2 SLP114 T01440011= ## 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 20210918015899A](https://openairdocs.org/incident/20210918015899A), Sep 18, 2021: Cessna 404, Sheridan, WY, Substantial damage. At 0740 on sept. 18, 2021 the airman lost consciousness upon landing at the Sheridan, WY (shr) airport. The aircraft, a Cessna 404 registered as N5409G went… ## Docket (3 files) The files NTSB released with the investigation on March 1, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103932. 2.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13204397&FileExtension=pdf&FileName=r_6120_1_Redacted-Rel.pdf - Photos (item 2, PDF, 2 pages, 407 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13204943&FileExtension=pdf&FileName=Photos-Rel.pdf - NTSB factual medical report (item 3, PDF, 3 pages, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15099091&FileExtension=pdf&FileName=WPR21LA350_Medical%20Factual%20Report%20V3-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.