# NTSB DCA24LA043: Boeing 787, N30913, Chicago, IL, October 19, 2023 - Type: NTSB incident investigation - Classification: Incident · No injuries · Class 4 · Limited · Final report - Date: October 18, 2023, 23:55 local (Oct 19, 2023, 04:55 UTC) - Place: Chicago, IL - Coordinates: 41.991893, -87.927607 - Nearby events: https://openairdocs.org/map.md?lat=41.9919&lon=-87.9276&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-from runway: Ground collision](https://openairdocs.org/ntsb-events/200) - Highest injury: No injuries - Injuries: 2 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 AVP-100 - NTSB case key (mKey): 193541 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA24LA043 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193541/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=193541 - Page: https://openairdocs.org/ntsb/DCA24LA043 ## Probable cause The flight crew’s misperception of the distance required to safely pass the hangar and failure to request additional ground handling support while taxiing, which resulted in a collision with a hangar. Contributing to the accident was United Airlines Maintenance Ramp personnel’s ambiguous taxi instructions and lack of obstruction clearance guidance. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Perception/orientation/illusion: perception](https://openairdocs.org/ntsb-findings/02022040): Personnel issues › Psychological · Flight crew (probable cause); cases with it: [Boeing 787-8, 1 case](https://openairdocs.org/ntsb-findings/02022040/cases.md?model=1388002), [All aircraft, 61 cases](https://openairdocs.org/ntsb-findings/02022040/cases.md) - [Communication (personnel): accuracy of communication](https://openairdocs.org/ntsb-findings/02063515): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Boeing 787-8, 1 case](https://openairdocs.org/ntsb-findings/02063515/cases.md?model=1388002), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/02063515/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi-from runway: Ground collision](https://openairdocs.org/ntsb-events/200) (defining event); cases with it: [Boeing 787-8, 2 cases](https://openairdocs.org/ntsb-events/200/sequence.md?model=1388002), [All aircraft, 618 cases](https://openairdocs.org/ntsb-events/200/sequence.md) ## Analysis United Airlines (UAL) flight 3885, a Boeing 787, impacted a hangar with its right-wing tip while taxiing to parking at Chicago O’Hare International Airport (KORD), Chicago, Illinois. The flight was a maintenance ferry flight conducted under Title 14 Code of Federal Regulations Part 91 from Newark Liberty International Airport (KEWR), Newark, New Jersey. According to the flight crew, after landing on runway 10C at ORD they were cleared to taxi to a UAL maintenance facility via taxiways P to Z. After receiving an air traffic control (ATC) clearance, they crossed runway 10L, continued via taxiway Z crossing both runways 9R and 9C before making a right turn onto taxiway D. Ground control cleared them to enter the ramp at taxiway YY1 and to contact UAL’s Maintenance Ramp frequency. UAL maintenance subsequently instructed them to make a left on YY, which was incorrect, and proceed to the north side of the ramp, where a truck with marshallers would be waiting to guide them to parking. After completing the left turn on YY, the flight crew realized they were about to enter an American Eagle ramp area instead of their intended destination of the UAL ramp area. Unfamiliar with the area they stopped the airplane and queried UAL maintenance as to where they should park. UAL maintenance asked the flight crew to proceed onto the American Eagle ramp and make a 180° turn. The captain noted no wingspan restrictions on the airport charts and no obstacles other than hangars in the area. He stated that there were no taxiway lights; however, there was adequate overhead lighting on the ramp. The captain then asked the first officer (FO) if they were clear to the right, to which the FO responded “yes”. Shortly thereafter, while proceeding onto the ramp and on the associated taxiway line they heard a loud bang and the airplane veered to the right. The FO looked out his window and stated, “we hit the hangar”. UAL Maintenance Ramp Area Figure 1 - Google Earth image with taxi route in red. The inset photo of accident site was provided by United Airlines. Green arrow indicates the location of United Airlines maintenance ramp area. The right-wing tip of the airplane struck a hanger resulting in minor damage to the wing. The damage to the hanger was estimated at about $236,000. A B787 has a wingspan of 197 feet 3 inches. The distance from the taxiway centerline to the hangar was about 98 ft accommodating a wingspan of about 196 ft. Had the marshallers met the airplane at American Eagle ramp and provided obstruction clearance guidance and/or the flight crew requested additional ground handling support before attempting to turn around in an unfamiliar area it is likely that the collision would not have occurred. ## Aircraft - Registration: [N30913](https://openairdocs.org/aircraft/N30913), registered now, S/N 35879, built 2014 (OpenAirDocs) - Reported make and model: BOEING 787 (8) - Registry model: [Boeing 787-8](https://openairdocs.org/model/boeing-787-8) (registry code 1388002) (OpenAirDocs) - Registry engine: [GE GENX-1B70/P2](https://openairdocs.org/engine/ge-genx-1b70-p2) (registry code 30228, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 35879 - Year built: 2014 - Airframe hours: 33459 - Engines: General Electric GEnx-1B 70000 lbs thrust turbo fan; General Electric GEnx-1B 70000 lbs thrust turbo fan - Damage: Minor damage - Flight: Ferry, Part 91 - Operator: United Airlines Inc - Registered owner: United Airlines Inc - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, December 11, 2023 - Departed: Newark, NJ - Destination: Same as departure - Flight plan: VFR/IFR - Airport: ORD, Chicago O'Hare Intl - Equipment: Onboard weather, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device, Data recorder, Angle of attack indicator, ADS-B, Stall warning system, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review September 24, 2023; seat: left; restraint: 5-point; flight hours: 26,480 total, 3,673 in this make and model, 3,673 as pilot in command, 250 in the last 90 days, 89 in the last 30 days - Co-pilot; age 44; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review October 5, 2023; seat: right; restraint: 5-point; flight hours: 14,552 total, 980 in this make and model, 1,500 as pilot in command, 131 in the last 90 days, 5 in the last 30 days ## Weather - Conditions: Visual (VMC), Night - Wind: 190° at 12 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: 9,000 ft overcast - Temperature: 59 °F, dew point 52 °F - Altimeter: 29.81 inHg - Observed at: KORD, 2 nm away - METAR: METAR KORD 190451Z 19012G18KT 10SM -RA FEW055 SCT075 OVC090 15/11 A2981 ## Docket (3 files) The files NTSB released with the investigation on March 12, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=193541. 5.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 5.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16555034&FileExtension=pdf&FileName=6120%20DMS_Redacted-Rel.pdf - Flight crew statements (item 2, PDF, 2 pages, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16556146&FileExtension=pdf&FileName=Crew%20Statements%20DMS-Rel.pdf - Photos (item 3, PDF, 2 pages, 684 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16556744&FileExtension=pdf&FileName=Photo%20Array-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.