# NTSB DCA11CA014: Boeing 737-7H4, N913WN, Philadelphia, PA, December 18, 2010 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 18, 2010, 11:00 local (16:00 UTC) - Place: Philadelphia, PA - Coordinates: 39.872222, -75.240837 - Nearby events: https://openairdocs.org/map.md?lat=39.8722&lon=-75.2408&mi=10 - Phase of flight: [Pushback/towing](https://openairdocs.org/ntsb-phases/200) (OpenAirDocs' grouping) - Defining events: [Pushback/towing: Ground handling event](https://openairdocs.org/ntsb-events/080); [Pushback/towing: Ground handling event](https://openairdocs.org/ntsb-events/080) - Highest injury: No injuries - Injuries: 222 uninjured - Status: Completed, report June 27, 2011 - Report: Approved by Office Director - NTSB office: Major Investigations Division - NTSB case key (mKey): 78035 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA11CA014 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78035/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78035 - Page: https://openairdocs.org/ntsb/DCA11CA014 ## Probable cause (aircraft 2) the failure of the ground operations personnel to maintain awareness of the relative position of the two airplanes. ## 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 · Ground crew (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) - [Personnel issues](https://openairdocs.org/ntsb-findings/02060000): Personnel issues › Task performance · Ground crew (probable cause), aircraft 2; cases with it: [Boeing 737-3H4, 2 cases](https://openairdocs.org/ntsb-findings/02060000/cases.md?model=138447K), [All aircraft, 137 cases](https://openairdocs.org/ntsb-findings/02060000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Pushback/towing: Ground handling event](https://openairdocs.org/ntsb-events/080) (defining event), aircraft 1; cases with it: [Boeing 737-7H4, 4 cases](https://openairdocs.org/ntsb-events/080/sequence.md?model=1384404), [All aircraft, 108 cases](https://openairdocs.org/ntsb-events/080/sequence.md) - [Pushback/towing: Ground handling event](https://openairdocs.org/ntsb-events/080) (defining event), aircraft 2; cases with it: [Boeing 737-3H4, 3 cases](https://openairdocs.org/ntsb-events/080/sequence.md?model=138447K), [All aircraft, 108 cases](https://openairdocs.org/ntsb-events/080/sequence.md) ## Analysis (aircraft 2) On December 18, 2010, at 1100 eastern standard time, a Boeing 737-700, registration number N913WN, operated by Southwest Airlines as flight 2592 to Fort Lauderdale, Florida, collided with a Boeing 737-300, registration number N650SW, operated by Southwest Airlines as flight 3944 to Tampa, Florida, during pushback from the gate at Philadelphia International Airport, Philadelphia, PA. The left wing and horizontal stabilizer of N913WN contacted the right winglet and horizontal stabilizer of N650SW. N650SW had been previously pushed back and awaiting taxi clearance at the time of the incident. The tug operator reported he looked away at an uninvolved airplane and when he looked back, the wing walker was signalling him to stop, but he was unable to stop prior to impact. N913WN was substantially damaged due to the impact to the wing spar. N650SW had minor damage. There were no injuries to the 10 total crew members, 215 total passengers, and 2 ground operations personnel. ## Factual narrative (aircraft 2) On December 18, 2010, at 1100 eastern standard time, a Boeing 737-700, registration number N913WN, operated by Southwest Airlines as flight 2592 to Fort Lauderdale, Florida, collided with a Boeing 737-300, registration number N650SW, operated by Southwest Airlines as flight 3944 to Tampa, Florida, during pushback from the gate at Philadelphia International Airport, Philadelphia, PA. The left wing and horizontal stabilizer of N913WN contacted the right winglet and horizontal stabilizer of N650SW. N650SW had been previously pushed back and awaiting taxi clearance at the time of the incident. The tug operator reported he looked away at an uninvolved airplane and when he looked back, the wing walker was signalling him to stop, but he was unable to stop prior to impact. N913WN was substantially damaged due to the impact to the wing spar. N650SW had minor damage. There were no injuries to the 10 total crew members, 215 total passengers, and 2 ground operations personnel. ## Aircraft 1 - Registration: [N913WN](https://openairdocs.org/aircraft/N913WN), registered now, S/N 29840, built 2008 (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 CFM56-7B24 series](https://openairdocs.org/engine/cfm-international-cfm56-7b24-series) (registry code 13044, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 29840 - Airframe hours: 9987 - 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 - Last inspection: Continuous airworthiness, December 18, 2010 - Departed: KPHL, Philadelphia, PA - Destination: KFLL, Fort Lauderdale, FL - Flight plan: IFR - Airport: KPHL, Philadelphia ## Aircraft 2 - Registration: [N650SW](https://openairdocs.org/deregistered/N650SW-2017-11-06), registration cancelled 2017-11-06, S/N 27720, built 1997 (OpenAirDocs) - Reported make and model: BOEING 737-3H4 - Registry model: [Boeing 737-3H4](https://openairdocs.org/model/boeing-737-3h4) (registry code 138447K) (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: 27720 - Airframe hours: 44479 - Engines: CFM INTL. CFM56 SERIES 2200 horsepower turbo fan; CFM INTL. CFM56 SERIES 2200 horsepower 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, December 18, 2010 - Departed: KPHL, Philadelphia, PA - Destination: KTPA, Tampa, FL - Flight plan: IFR - Airport: KPHL, Philadelphia ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N913WN; age 44; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review February 15, 2010; seat: left; flight hours: 12,106 total, 7,800 in this make and model - Co-pilot, aircraft N913WN; age 36; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review February 15, 2010; seat: right; flight hours: 5,620 total, 3,000 in this make and model - Pilot, aircraft N650SW; age 57; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1; seat: left; flight hours: 13,000 total, 9,500 in this make and model - Co-pilot, aircraft N650SW; age 39; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1; seat: right; flight hours: 6,586 total, 4,086 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 280° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 34 °F - Altimeter: 30.18 inHg - Observed at: KPHL ## 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 20101218054602A](https://openairdocs.org/incident/20101218054602A), Dec 18, 2010: Boeing 737-7H4, Philadelphia, PA, Substantial damage. On December 18, 2010, southwest airlines (swa) flight 3944 (N650SW) received clearance from phl ramp control 2 for pushback from gate E-11 at 1103 EST. It was… - [Accident 20101218054652A](https://openairdocs.org/incident/20101218054652A), Dec 18, 2010: Boeing 737-3H4, Philadelphia, PA, Minor damage. On December 18, 2010, southwest airlines (swa) flight 3944 (N650SW) received clearance from phl ramp control 2 for pushback from gate E-11AT 1103 EST. It was… ## Other investigations on N913WN (1) 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. - [NTSB WPR13IA226](https://openairdocs.org/ntsb/WPR13IA226), May 10, 2013: Boeing 737-7H4 (N913WN), Phoenix, AZ, incident, minor damage. Probable cause: The failure of the tug operator and wing walker to adequately monitor the environment during pushback of the airplane from the gate in preparation for flight, which led to the collision of the… ## Docket (11 files) The files NTSB released with the investigation on June 27, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78035. 4.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - N650SW (item 1, .PDF, 579 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343038&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20N650SW-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - N913WN (item 2, .PDF, 428 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343039&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20N913WN-Redacted.PDF - Operations 2 - Flight Ops Statements (item 3, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343044&FileExtension=.PDF&FileName=Operations%202%20-%20Flight%20Ops%20Statements-Redacted.PDF - Operations 2 - Ground Ops Statements (item 4, .PDF, 138 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343043&FileExtension=.PDF&FileName=Operations%202%20-%20Ground%20Ops%20Statements-Redacted.PDF - Witness Statement - Aircraft Maintenance Technician (item 5, .PDF, 546 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343041&FileExtension=.PDF&FileName=Witness%20Statement%20-%20Aircraft%20Maintenance%20Technician-Redacted.PDF - Survival Factors 6 - Inflight Crew Statements (item 6, .PDF, 11 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343042&FileExtension=.PDF&FileName=Survival%20Factors%206%20-%20Inflight%20Crew%20Statements-Redacted.PDF - Structures 7 - Damage Assessment (item 7, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343045&FileExtension=.PDF&FileName=Structures%207%20-%20Damage%20Assessment-Redacted.PDF - Photo 1 (item 8, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343067&FileExtension=.PDF&FileName=Photo%201-Master.PDF - Photo 2 (item 9, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343068&FileExtension=.PDF&FileName=Photo%202-Master.PDF - Photo 3 (item 10, .PDF, 78 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343069&FileExtension=.PDF&FileName=Photo%203%0D%0A-Master.PDF - Photo 4 (item 11, .PDF, 129 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40343070&FileExtension=.PDF&FileName=Photo%204-Master.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.