# NTSB WPR10LA134: Boeing 737-7H4, N221WN, Santa Clarita, CA, February 13, 2010 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: February 13, 2010, 14:45 local (22:45 UTC) - Place: Santa Clarita, CA - Coordinates: 34.46389, -118.51361 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.4639&lon=-118.5136&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-IFR initial approach: Abrupt maneuver](https://openairdocs.org/ntsb-events/270) - Highest injury: Serious injuries - Injuries: 1 serious, 1 minor, 83 uninjured - Status: Completed, report February 12, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administratin, Southwest Airlines Co. - NTSB case key (mKey): 75365 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR10LA134 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/75365/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=75365 - Page: https://openairdocs.org/ntsb/WPR10LA134 ## Probable cause The pilot’s abrupt airplane pitch change maneuver. Contributing to the accident was the flight crew’s failure to maintain the heading specified by the air traffic controller, which would have avoided the near collision course with an unidentified airplane that triggered the traffic alert and collision avoidance system resolution advisory. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: pitch control](https://openairdocs.org/ntsb-findings/01062022): Aircraft › Aircraft oper/perf/capability · Incorrect use/operation (probable cause); cases with it: [Boeing 737-7H4, 1 case](https://openairdocs.org/ntsb-findings/01062022/cases.md?model=1384404), [All aircraft, 526 cases](https://openairdocs.org/ntsb-findings/01062022/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Boeing 737-7H4, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=1384404), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Air traffic/operating proc](https://openairdocs.org/ntsb-findings/03014000): Environmental issues › Operating environment · Compliance w/ procedure (probable cause); cases with it: [Boeing 737-7H4, 2 cases](https://openairdocs.org/ntsb-findings/03014000/cases.md?model=1384404), [All aircraft, 13 cases](https://openairdocs.org/ntsb-findings/03014000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-IFR initial approach: Collision avoidance alert](https://openairdocs.org/ntsb-events/420); cases with it: [Boeing 737-7H4, 1 case](https://openairdocs.org/ntsb-events/420/sequence.md?model=1384404), [All aircraft, 11 cases](https://openairdocs.org/ntsb-events/420/sequence.md) - [Approach-IFR initial approach: Abrupt maneuver](https://openairdocs.org/ntsb-events/270) (defining event); cases with it: [Boeing 737-7H4, 1 case](https://openairdocs.org/ntsb-events/270/sequence.md?model=1384404), [All aircraft, 346 cases](https://openairdocs.org/ntsb-events/270/sequence.md) ## Analysis During descent to landing, the flight crew inadvertently turned about 27 degrees off their air traffic controller-assigned heading. When advised by the controller to check the airplane’s heading, the flight crew noted the heading discrepancy and immediately initiated a turn back to the assigned heading. During the turn, the flight crew received a traffic alert and collision avoidance system resolution advisory (RA). The captain responded to the RA by initiating an estimated 1,500- to 2,000-foot-per-minute rate of descent followed by an approximate 2,000-foot-per-minute climb. During the RA response maneuvers, three flight attendants were standing in the aft galley, one of whom was seriously injured. ## Factual narrative On February 13, 2010, about 1445, Pacific standard time, a Boeing 737-7H4, N221WN, abruptly maneuvered during radar vectors for initial approach to the Bob Hope Airport, Burbank, California. At the time, the airplane was about 20 miles northwest of Burbank. The 2 pilots, 80 passengers and 1 of the 3 flight attendants were not injured. The remaining 2 flight attendants sustained a minor and a serious injury. The airplane was not damaged. The airplane was registered and operated by Southwest Airlines as Flight #2534, under the provisions of Title 14 Code of Federal Regulations Part 121. Visual meteorological conditions prevailed for the flight which was operated on an instrument flight rules flight plan. The scheduled domestic passenger flight originated from Las Vegas, Nevada, at 1354. The Airline Transport Pilot (ATP) captain stated that he was the pilot flying and the ATP First Officer was the pilot monitoring, as they descended for landing. The Approach Air Traffic Controller (ATC) issued the flight a clearance to fly a 190-degree heading and descend to and maintain 6,000 feet. The captain stated that he set a 190 degree heading in the heading window and selected 6,000 feet in the altitude window of the airplane's mode control panel (MCP) used to set autopilot functions and was subsequently verified by the first officer. The captain stated that as the flight continued, the controller issued a traffic information alert for traffic at their 11 o'clock position and roughly 4 miles away. The captain said that the flight crew began scanning for the traffic and received a Traffic Collision Avoidance System (TCAS) traffic advisory (TA), which identified that the traffic was about 500 feet below their airplane's altitude. The captain stated that he began to shallow the airplane's rate of descent to its assigned altitude of 6,000 feet to avoid the traffic. Subsequently, the controller advised the flight crew to check the airplane's heading. The captain said that he noticed that he had inadvertently allowed the airplane to turn to a 163-degree heading and immediately initiated a turn back to the assigned heading of 190 degrees. During the turn, the crew received a TCAS resolution alert (RA) to descend at 1,500 to 2,000 feet per minute (fpm), followed by a command to climb at 2,000 fpm. The captain further reported that the RA commands were followed and that during the climb portion, they observed traffic ahead of their position about 2 miles away and slightly higher in altitude. The captain stated that he responded by making a shallow turn to the right to avoid the traffic. At the time of the accident, all of the passengers were seated with their seatbelts fastened. The flight attendants stated that all three of them were standing in the aft galley and were making their final preparations for landing. One flight attendant sustained a fractured left scapula. ## Aircraft - Registration: [N221WN](https://openairdocs.org/aircraft/N221WN), registered now, S/N 34259, built 2005 (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: [GE CFM56 series](https://openairdocs.org/engine/ge-cfm56-series) (registry code 30016, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 34259 - Airframe hours: 16848 - Engines: GE CFM56 SERIES 24000 lbs thrust turbo fan; GE CFM56 SERIES 9800 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, February 7, 2010 - Departed: LAS, Las Vegas, NV - Destination: BUR, Burbank, CA - Flight plan: IFR - Airport: BUR, Bob Hope, runway 08, 5,802 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; flight engineer, airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review October 28, 2009; seat: left; flight hours: 21,688 total, 9,377 in this make and model, 11,413 as pilot in command, 218 in the last 90 days, 77 in the last 30 days, 4 in the last 24 hours - Co-pilot; age 45; injuries: none; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review January 8, 2009; seat: right; flight hours: 5,505 total, 1,730 in this make and model, 3,370 as pilot in command, 218 in the last 90 days, 57 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 170° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 72 °F, dew point 37 °F - Altimeter: 30.03 inHg - Observed at: BUR, 20 nm away ## 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 20100213036019A](https://openairdocs.org/incident/20100213036019A), Feb 13, 2010: Boeing 737-7H4, Santa Clartia, CA, No damage. Southwest airlines flight 2534 was on the lynxx 8 arrival to bur. ATC vectored the aircraft off the lynxx 8 arrival. ATC instructed the aircraft to turn left… ## Docket (8 files) The files NTSB released with the investigation on December 12, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=75365. 3.9 MB in all. - Flight Data Recorder 10 - Specialist's Factual Report (item 1, .PDF, 219 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341966&FileExtension=.PDF&FileName=Flight%20Data%20Recorder%2010%20-%20Specialist%27s%20Factual%20Report-Master.PDF - Flight Data Recorder 10 - Attachment 1 - Tabular Data - Flight - (CSV Format) (item 2, .CSV, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40341968&FileExtension=.csv&FileName=Flight%20Data%20Recorder%2010%20-%20Attachment%201%20-%20Tabular%20Data%20-%20Flight%20-%20(CSV%20Format)-Master.csv - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 3, .PDF, 514 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337961&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Statements of Captain and First Officer (item 4, .PDF, 513 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40381393&FileExtension=.PDF&FileName=Statements%20of%20Captain%20and%20First%20Officer-Redacted.PDF - Statements of Flight Attendants, A, B and C (item 5, .PDF, 714 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40381396&FileExtension=.PDF&FileName=Statements%20of%20Flight%20Attendants,%20A,%20B%20and%20C-Redacted.PDF - Flight Track Map (item 6, .PDF, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337965&FileExtension=.PDF&FileName=Flight%20Track%20Map-Master.PDF - Aircraft Log Sheet (item 7, .PDF, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40381397&FileExtension=.PDF&FileName=Aircraft%20Log%20Sheet-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 8, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40337964&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.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.