# NTSB ERA21LA134: Cessna 421, N84HA, St. Marys, PA, February 22, 2021 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 3 · Limited · Final report - Date: February 22, 2021, 11:45 local (16:45 UTC) - Place: St. Marys, PA - Coordinates: 41.412288, -78.498793 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.4123&lon=-78.4988&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: Minor injuries - Injuries: 1 minor, 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: Cossin - NTSB case key (mKey): 102658 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA21LA134 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102658/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=102658 - Page: https://openairdocs.org/ntsb/ERA21LA134 ## Probable cause The pilot’s decision to continue the approach to a snow-covered runway in low-visibility conditions with limited ability to visually differentiate the left runway edge from the snow berm that ran along that side of the runway. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Cessna 421C, 6 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=2076016), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Environmental issues](https://openairdocs.org/ntsb-findings/03030000): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Cessna 421C, 1 case](https://openairdocs.org/ntsb-findings/03030000/cases.md?model=2076016), [All aircraft, 57 cases](https://openairdocs.org/ntsb-findings/03030000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Cessna 421C, 3 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2076016), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Cessna 421C, 9 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2076016), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis After the pilot performed a GPS approach in light snow and with 0.5-mile visibility, the airplane touched down on the left edge of the snow-covered runway and struck a snow berm. The airplane slid along the snow berm before it rotated about 210° and came to a stop. The airplane sustained substantial damage to the forward fuselage, the pressure bulkhead, and the floor area forward of the bulkhead. The runway, its markings, and the runway lighting were covered in snow that was 3 to 4 inches deep. The snow depth, combined with the limited visibility, likely resulted in the pilot’s difficulty in identifying the runway edge from the snow berm on the left side of the runway. The notices to air mission (NOTAM) published for the airport did not contain any field conditions noting the snow depth or the snow-covered runway lights. Furthermore, the airport manager, who was new to the position, was not able to issue a NOTAM about the runway conditions because he had not yet been authorized to do so. ## Factual narrative On February 22, 2021, about 1145 eastern standard time, a Cessna 421C, N84HA, was substantially damaged when it was involved in an accident at St. Marys Municipal Airport (OYM), St. Marys, Pennsylvania. The airline transport pilot sustained minor injuries, and the two passengers were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 corporate flight. The pilot recalled that, while the airplane was inbound to OYM, the automated weather observing system reported the cloud conditions as 600 ft broken and 1,000 ft overcast and the visibility as 1.5 miles in snow. Before being cleared for the GPS approach to runway 28, air traffic control provided notices to air mission (NOTAM) regarding an inoperative remote communications outlet and several lighted obstructions (towers) near the airport. The pilot also recalled these NOTAMs were the same as the ones that he had reviewed before departure. As the pilot began the approach, he was able to “pick up ground contact,” and, just before the airplane reached the minimum descent altitude, he saw the approach lights. As the airplane flew over the approach lights, the pilot could see the “outline of the runway.” After touchdown, the airplane struck a snow berm on the left side of the runway. Examination of the accident site revealed ground scars in the snow to the left of the runway edge, beginning about 1,000 ft from the approach end of runway 28. The marks were about 250 ft long and tracked along and through a snow berm on the left side of the runway. The airplane came to rest at the end of the snow marks and was oriented on a magnetic heading of about 130° (rotated about 210° from the runway 28 heading). At the time of the accident, the runway was covered in snow estimated to be about 3-4 inches deep. The runway edge lights, and runway end identifier lights were beneath the snow. Examination of the airplane revealed bending/displacement of the forward pressure bulkhead, buckling of the floor just forward of the pressure bulkhead, and a slight displacement of the left wing from the fuselage at the wing root. The pilot reported that the day before the accident, he contacted officials at the airport, advising of his planned arrival. It was the pilot’s understanding that airport personnel would plow the runway prior to his arrival. After the accident, the pilot learned that the airport snowplow had become stuck while plowing a side road adjacent to the airport prior to his arrival. A review of Federal Aviation Administration records revealed no NOTAMs regarding the snow on the runway, the obscuration of the runway lights, or any other field condition before the accident. According to the Federal Aviation Administration, the airport manager reported that he was relatively new in his position and that he had not been placed on the list of personnel who were authorized to issue NOTAMs. After the accident, the airport manager coordinated with the Federal Aviation Administrationto be placed on that list. The 1135 weather conditions reported at OYM included clouds broken at 700 ft and overcast at 1,100 ft and visibility 0.5 mile in light snow. The visibility was reported as 0.5 mile in snow or light snow during the three previous observations (recorded at 1035, 1055, and 1115). ## Aircraft - Registration: [N84HA](https://openairdocs.org/deregistered/N84HA-2024-02-15), registration cancelled 2024-02-15, S/N 421C-1407, built 1984 (OpenAirDocs) - Reported make and model: CESSNA 421 (C) - Registry model: [Cessna 421C](https://openairdocs.org/model/cessna-421c) (registry code 2076016) (OpenAirDocs) - Registry engine: [Continental GTSI0-520-F-K](https://openairdocs.org/engine/continental-gtsi0-520-f-k) (registry code 17031, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 421C-1407 - Year built: 1984 - Airframe hours: 4211 - Engines: CONT MOTOR GTSI0-520-N 375 horsepower reciprocating; CONT MOTOR GTSI0-520-N 375 horsepower reciprocating - Damage: Substantial damage - Flight: Executive/Corporate, Part 91 - Operator: Wheels Up LLC - Registered owner: Wheels Up LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, February 19, 2021, 2 hours before - Departed: BDR, Bridgeport, CT - Destination: Same as departure - Flight plan: IFR - Airport: OYM, St Marys Muni, runway 28, 4,300 × 75 ft, asphalt - Equipment: Stall warning system, ADS-B, Auto-pilot, Electronic multifunction display, Onboard weather ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: minor; commercial, flight engineer, airline transport; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review August 10, 2019; seat: left; restraint: 3-point; flight hours: 31,000 total, 196 in this make and model, 30,600 as pilot in command, 4 in the last 90 days, 1.7 in the last 30 days, 1.7 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 160° at 7 knots - Visibility: 0.5 statute miles - Lowest ceiling: 700 ft broken - Temperature: 28 °F, dew point 28 °F - Altimeter: 29.72 inHg - Observed at: OYM ## 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 20210222005269A](https://openairdocs.org/incident/20210222005269A), Feb 22, 2021: Cessna 421C, St. Mary'S, PA, Substantial damage. On February 22, 2021, pilot in command [privacy data omitted], obtained a preflight weather briefing via foreflite prior to departure for a flight originating… ## Docket (5 files) The files NTSB released with the investigation on December 19, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=102658. 6.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 7 pages, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12762134&FileExtension=pdf&FileName=01-01%20NTSB%20Form%206120_print_Redacted-Rel.pdf - Memorandum for record - information from FAA inspector (item 2, PDF, 2 pages, 215 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12761423&FileExtension=pdf&FileName=01-04%20%20MFR%20-%20Information%20from%20FAA%20Inspector_ERA21LA134-Rel.pdf - Weather reports and records (item 3, PDF, 2 pages, 108 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12761626&FileExtension=pdf&FileName=04-01%20Metars_KOYM_Feb_22_2021-Rel.pdf - Records of published notices to airmen (oym) (item 4, PDF, 1 page, 141 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12761806&FileExtension=pdf&FileName=05-01%20OYM%20NOTAMs%202-23-21-Rel.pdf - Investigative photographs (item 5, PDF, 4 pages, 4 photos, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12762144&FileExtension=pdf&FileName=06-01-%20photo%20array_ERA21LA134-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.