# NTSB DCA21LA133: Boeing 737-7H4, N289CT, Chicago, IL, May 21, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: May 21, 2021, 12:30 local (17:30 UTC) - Place: Chicago, IL - Coordinates: 41.785, -87.752 - Nearby events: https://openairdocs.org/map.md?lat=41.7850&lon=-87.7520&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining events: [Taxi: Ground collision](https://openairdocs.org/ntsb-events/200); [Taxi-to runway: Ground collision](https://openairdocs.org/ntsb-events/200) - Highest injury: No injuries - Injuries: 214 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Major Investigations Division - Parties: Boeing, FAA, SWA - NTSB case key (mKey): 103134 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA21LA133 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103134/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103134 - Page: https://openairdocs.org/ntsb/DCA21LA133 ## Probable cause (aircraft 1) the failure of the flight crew of N8686A to provide sufficient clearance while taxiing past N289CT, which was stopped. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Pilot of other aircraft (probable cause), aircraft 1; cases with it: [Boeing 737-7H4, 7 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=1384404), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Flight crew (probable cause), aircraft 2; cases with it: [Boeing 737-8H4, 4 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=138440A), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event), aircraft 1; cases with it: [Boeing 737-7H4, 8 cases](https://openairdocs.org/ntsb-events/200/sequence.md?model=1384404), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md) - [Taxi-to runway: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event), aircraft 2; cases with it: [Boeing 737-8H4, 3 cases](https://openairdocs.org/ntsb-events/200/sequence.md?model=138440A), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md) ## Analysis (aircraft 1) On May 21, 2021, at about 1230 central daylight time, two Southwest B737’s collided while taxiing near the gate area at Chicago Midway International Airport (MDW), Chicago, Illinois. There were no injuries to the passengers and crew onboard either airplane. One airplane was substantially damaged and the other received minor damage. According to the operator, after landing, N289CT taxied to the assigned gate B-15 and was awaiting the ground marshalling crew. The flight crew of N289CT reported that they positioned the airplane on the J-line leading to the gate parking spot and set the brake while awaiting the ground crew. The marshallers arrived and began to signal the crew into the gate. Shortly after releasing the parking brake, the flight crew reported feeling the airplane shudder. The captain looked out the left window and noticed the N8686A taxiing behind with damage to its right winglet. N289CT then proceeded to the gate and deplaned with no further incident. Post accident inspection of the airplane revealed substantial damage to both elevators. N8686A was cleared to taxi from gate B14 to runway 22L via taxiways T and Y. While taxiing NE on taxiway Y, the aircraft's right winglet struck the aft portion of N289CT's horizontal stabilizer. N8686A taxied back to the gate. Post accident inspection of the airplane revealed minor damage to the right winglet. ## Factual narrative (aircraft 1) According to the operator of both airplanes; N289CT taxied to the assigned gate B-15 and was awaiting the ground marshalling crew. The flight crew of N289CT reported that they positioned the airplane on the J-line leading to the gate parking spot and set the brake while awaiting the ground crew. The marshallers arrived and began to signal the crew into the gate. Shortly after releasing the parking brake, the flight crew reported feeling the airplane shudder and stopped moving. The flight crew noticed the other aircraft taxiing behind with damage to the right wingtip. They then proceeded to the gate and deplaned with no further incident. Inspection of the airplane revealed substantial damage to both elevators. N8686A was cleared to taxi from gate B14 to Runway 22L via taxiways T and Y. While taxiing NE on taxiway Y, the aircraft's right wingtip struck the aft portion of N289CT's horizontal stabilizer. ## Aircraft 1 - Registration: [N289CT](https://openairdocs.org/aircraft/N289CT), registered now, S/N 36633, built 2007 (OpenAirDocs) - Reported make and model: BOEING 737-7H4 (700) - Registry model: [Boeing 737-7H4](https://openairdocs.org/model/boeing-737-7h4) (registry code 1384404) (OpenAirDocs) - Registry engine: [CFM International CFM56-7B24 series](https://openairdocs.org/engine/cfm-international-cfm56-7b24-series) (registry code 13044, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 36633 - Year built: 2007 - Engines: CFM INTL CFM56-7B24 24200 lbs thrust turbo fan; CFM INTL CFM56-7B24 24200 lbs thrust turbo fan - Damage: Substantial damage - Flight: Part 121 - Operator: Southwest Airlines Co - Registered owner: Southwest Airlines Co - Airworthiness certificate: Standard, Transport - Departed: KIAD, Washington, DC - Destination: Same as departure - Flight plan: IFR - Airport: KMDW, Midway - Equipment: Data recorder ## Aircraft 2 - Registration: [N8686A](https://openairdocs.org/aircraft/N8686A), registered now, S/N 36938, built 2016 (OpenAirDocs) - Reported make and model: BOEING 737-8H4 (800) - Registry model: [Boeing 737-8H4](https://openairdocs.org/model/boeing-737-8h4) (registry code 138440A) (OpenAirDocs) - Registry engine: [CFM International CFM56-7B27E/F series](https://openairdocs.org/engine/cfm-international-cfm56-7b27e-f-series) (registry code 13100, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 36938 - Year built: 2016 - Airframe hours: 17191 - Engines: CFM INTL CFM56-7B27E/F 27300 lbs thrust turbo fan; CFM INTL CFM56-7B27E/F 27300 lbs thrust turbo fan - Damage: Minor damage - Flight: Part 121 - Operator: Southwest Airlines Co - Registered owner: Southwest Airlines Co - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, May 18, 2021 - Destination: KBHM, Birmingham, AL - Flight plan: IFR - Equipment: ADS-B, Stall warning system, Angle of attack indicator, Auto-pilot, Onboard weather, Heads up display, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device, Data recorder ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N289CT; age 60; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: left; restraint: 5-point; flight hours: 25,000 total, 22,000 in this make and model, 20,000 as pilot in command, 150 in the last 90 days, 100 in the last 30 days, 5 in the last 24 hours - Co-pilot, aircraft N289CT; age 46; injuries: none; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: right; restraint: 5-point; flight hours: 6,300 total, 3,274 in this make and model, 5,300 as pilot in command, 213 in the last 90 days, 70 in the last 30 days, 4 in the last 24 hours - Pilot, aircraft N8686A; age 56; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review November 20, 2020; seat: left; restraint: 5-point; flight hours: 18,485 total, 4,050 in this make and model, 13,000 as pilot in command, 171 in the last 90 days, 55 in the last 30 days, 7 in the last 24 hours - Co-pilot, aircraft N8686A; age 48; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: helicopter, airplane; medical: class 1, without waivers/limitations; last flight review October 5, 2020; seat: right; restraint: 5-point; flight hours: 7,564 total, 2,606 in this make and model, 1,400 as pilot in command, 154 in the last 90 days, 33 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 210° at 15 knots, gusting 25 - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 82 °F, dew point 54 °F - Altimeter: 30.34 inHg - Observed at: KMDW ## FAA reports on this event (2) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20210521004232A](https://openairdocs.org/incident/20210521004232A), May 21, 2021: Boeing 737-7H4, Chicago, IL, Substantial damage. On may 21, 2021 at Midway International Airport, Chicago, IL, [privacy data omitted], was proceding on their ATC clearance to taxi to runway 22L, from gate… - [Accident 20210521004242A](https://openairdocs.org/incident/20210521004242A), May 21, 2021: Boeing 737-8H4, Chicago, IL, Minor damage. On may 21, 2021 at Midway international airport, Chicago, IL, [privacy data omitted], operating as [privacy data omitted], was proceding on their ATC clearance… ## Docket (3 files) The files NTSB released with the investigation on January 6, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103134. 4.2 MB in all. - N8686A pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12665789&FileExtension=pdf&FileName=r_SWA%20654_MDW_N8686A-Rel.pdf - N289CT pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12666138&FileExtension=pdf&FileName=r_SWA%20751_MDW_N289CT-Rel.pdf - Pilot's statements (item 3, PDF, 2 pages, 129 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12666412&FileExtension=pdf&FileName=MDW%20Accident%20Pilot%20Statements-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.