# NTSB DCA24LA124: Boeing 737, N411WN, Aylett, VA, March 9, 2024 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 4 · Limited · Final report - Date: March 9, 2024, 13:31 local (18:31 UTC) - Place: Aylett, VA · lat long as provided by SWA (same as IS on 6120), also explained as 95 mi SW of BWI, @ 23,030 ft - Coordinates: 37.846, -77.232 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.8460&lon=-77.2320&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-descent: Turbulence encounter](https://openairdocs.org/ntsb-events/360) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor, 105 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Major Investigations Division - Parties: FAA - NTSB case key (mKey): 193920 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA24LA124 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193920/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193920 - Page: https://openairdocs.org/ntsb/DCA24LA124 ## Probable cause An encounter with clear air turbulence during descent. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Turbulence: clear air turbulence](https://openairdocs.org/ntsb-findings/03032015): Environmental issues › Conditions/weather/phenomena · Effect on personnel (probable cause); cases with it: [Boeing 737-7H4, 7 cases](https://openairdocs.org/ntsb-findings/03032015/cases.md?model=1384404), [All aircraft, 78 cases](https://openairdocs.org/ntsb-findings/03032015/cases.md) - [Turbulence: clear air turbulence](https://openairdocs.org/ntsb-findings/03032015): Environmental issues › Conditions/weather/phenomena · Awareness of condition; cases with it: [Boeing 737-7H4, 7 cases](https://openairdocs.org/ntsb-findings/03032015/cases.md?model=1384404), [All aircraft, 78 cases](https://openairdocs.org/ntsb-findings/03032015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-descent: Turbulence encounter](https://openairdocs.org/ntsb-events/360) (defining event); cases with it: [Boeing 737-7H4, 16 cases](https://openairdocs.org/ntsb-events/360/sequence.md?model=1384404), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) ## Analysis On March 9, 2024, at 1331 eastern standard time, Southwest Airlines flight 4318 encountered turbulence during initial descent into Baltimore Washington International airport (BWI), Baltimore, Maryland. The flight was a regularly scheduled passenger flight from Northwest Florida Beaches International Airport (ECP), Panama City, Florida to BWI. As a result of the turbulence, one flight attendant sustained serious injuries. The airplane was not damaged, and the flight continued to BWI without further incident. The flight deck crew reported that they were aware of, and had received, pilot reports of turbulence at lower altitudes on arrival into BWI. They had coordinated with the cabin crew during their preflight briefing about securing the cabin early and reiterated this again (as well as asking them to take their seats afterward) just prior to starting a standard terminal arrival (the RAVNN SIX) into BWI. As they began the arrival, they learned of a pilot report of severe turbulence at flight level (FL) 250 from an airplane on arrival into nearby Ronald Reagan Washington National Airport (DCA), Arlington, Virginia. While the cabin crew were securing the cabin and galleys, the airplane encountered severe turbulence as it descended through FL270. The captain immediately made a public address announcement to the cabin for the flight attendants to take their seats. Flight attendants B and C were “tossed around….sent into the air” before landing on the floor of the aft galley. Flight attendant C sustained a hairline fracture to the left arm. A non-revenue Southwest Airlines flight attendant who was seated in the rear of the airplane rendered assistance to flight attendant C. The captain declared a medical emergency and received an expedited approach into BWI. The first officer coordinated with airline operations and arranged for medical personnel to meet the airplane at the gate. A post-accident review of weather records revealed that there were four pilot reports of moderate to severe turbulence from FL160 to FL250 in an area to the southwest of the accident location. A high-resolution rapid refresh numerical model computed for the time and location of the accident revealed that conditions were conducive for moderate clear air turbulence from FL250 to FL280. Infrared and visible satellite imagery depicted a transverse wave cloud pattern (often observed in turbulent conditions) over the accident area. The cloud temperatures were consistent with cloud tops near 33,000 ft above mean sea level. A graphical Airmen’s Meteorological (G-AIRMET) information Tango (turbulence), issued by the National Weather Service, valid at the time of the accident advised of occasional moderate turbulence between FL180 and FL380 for much of the mid-Atlantic and northeast states. Graphic turbulence guidance products predicted areas of moderate turbulence over central Virginia moving northwest between 1300 and 1400 eastern standard time, at FL240. ## Aircraft - Registration: [N411WN](https://openairdocs.org/deregistered/N411WN-2025-09-29), registration cancelled 2025-09-29, S/N 29821, built 2001 (OpenAirDocs) - Reported make and model: BOEING 737 (7H4) - Registry model: [Boeing 737-7H4](https://openairdocs.org/model/boeing-737-7h4) (registry code 1384404) (OpenAirDocs) - Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 29821 - Year built: 2001 - Airframe hours: 74369 - Engines: CFM INTL. CFM56-7B24 24000 lbs thrust turbo fan; CFM INTL. CFM56-7B24 24000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: Southwest Airlines Co - Registered owner: Southwest Airlines Co - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, March 6, 2024 - Departed: ECP, Panama City, FL - Destination: BWI, Baltimore, MD - Flight plan: IFR - Equipment: Stall warning system, Satellite tracking device, Onboard weather, Heads up display, Electronic primary flight display, Electronic multifunction display, Data recorder, Auto-pilot, Angle of attack indicator, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 1, without waivers/limitations; last flight review July 27, 2023; seat: left; restraint: 5-point; flight hours: 19,000 total, 11,500 in this make and model, 7,600 as pilot in command, 194 in the last 90 days, 65 in the last 30 days, 0 in the last 24 hours - Co-pilot; age 49; injuries: none; airline transport; airplane ratings: multi-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review August 6, 2023; seat: right; restraint: 5-point; flight hours: 10,473 total, 5,369 in this make and model, 190 in the last 90 days, 83 in the last 30 days, 6 in the last 24 hours - Cabin crew; injuries: serious; seat: none; restraint: none ## Weather - Conditions: Instrument (IMC), Day - Wind: 180° at 8 knots, gusting 21 - Visibility: 4 statute miles - Lowest ceiling: 9 ft broken - Temperature: 54 °F, dew point 54 °F - Altimeter: 29.75 inHg - Turbulence: Severe - Observed at: KOFP, 13 nm away - METAR: KOFP 091832Z AUTO 13008G21KT 100V160 4SM RA BR BKN009 OVC014 12/12 A2975 RMK AO2 PRESFR P0006 T01220117= ## Docket (3 files) The files NTSB released with the investigation on April 30, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193920. 5.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16980431&FileExtension=pdf&FileName=01-01%206120_DCA24LA124_print_redacted_Redacted2-Rel.pdf - Crew statements (item 2, PDF, 3 pages, 199 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16949331&FileExtension=pdf&FileName=01-23%20SWA4318%20Crew%20Statements_Redacted-Rel.pdf - Weather reports and records (item 3, PDF, 11 pages, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16979687&FileExtension=pdf&FileName=06-01%20Weather%20Reports%20and%20Records5-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.