# NTSB FTW99LA207: Boeing 737-3H4, N650SW, Lafayette, LA, June 26, 1999 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: June 25, 1999, 19:45 local (Jun 26, 1999, 00:45 UTC) - Place: Lafayette, LA - Location: 30.2241° N, 92.0198° W: Placed by OpenAirDocs: center of Lafayette, LA, within about 6 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=30.2241&lon=-92.0198&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 141 uninjured - Status: Completed, report December 4, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46933 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW99LA207 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46933/pdf - Page: https://openairdocs.org/ntsb/FTW99LA207 ## Probable cause The pilot's inadvertent flight into an adverse weather condition. A factor was the turbulence. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, cruise - normal - flight into adverse weather - inadvertent, pilot in command (cause) - weather condition - turbulence in clouds (contributing factor) ## Analysis The flight encountered turbulence while at FL330. The destination airport was reporting thunderstorm activity near the airport. The fasten seat belt light had been turned on and the passengers briefed about the possibility of encountering turbulence during the approach. The airplane entered a stratus layer of clouds with a small cell approximately 20 miles to the left of the airplane's flight path. The captain reported that the airplane experienced a 'sudden jolt' followed by 10 to 12 seconds of light to occasionally moderate turbulence. The turbulence ceased once the airplane exited the clouds, with smooth air prevailing for the rest of the flight. A flight attendant in the aft cabin sustained a broken ankle. ## Factual narrative On June 25, 1999, approximately 1945 central daylight time, a Boeing 737-3H4 transport category airplane, N650SW, operating as Southwest Airlines Flight 1257, was undamaged during an in-flight encounter with turbulence near Lafayette, Louisiana. A flight attendant working in the aft galley was seriously injured. The 137 passengers, 2 flight crewmembers, and 2 other flight attendants were not injured. The airplane was owned and operated by Southwest Airlines Co., of Dallas, Texas. Instrument meteorological conditions prevailed for the Title 14 Code of Federal Regulations Part 121 flight for which an instrument flight rules (IFR) flight plan was filed. The scheduled domestic passenger flight was dispatched from the Houston Hobby Airport (HOU) at approximately 1918, with the New Orleans International Airport/Moisant Field (MSY) near New Orleans, Louisiana, as its intended destination. The captain, who was the non flying pilot, reported that while in cruise flight at FL330, approximately 125 miles west of MSY, he became aware of thunderstorm activity over MSY after receiving the current ATIS for MSY. The captain stated that he informed the first officer of the weather, and the first officer turned on the seat belt sign and made an announcement to the passengers that the flight was about to initiate a descent into MSY. He briefed the passengers about the possibility of encountering turbulence while in the vicinity of thunderstorms during the descent and approach phase of the flight. The captain further stated that several minutes later, the flight entered an area "of stratus-like clouds" with a small cell approximately 20 miles to the left of their flight path. The captain reported that the airplane experienced a "sudden jolt" which he described as "similar to crossing the wake of another 737 at 90 degrees." The jolt was followed by 10 to 12 seconds of light to occasional moderate turbulence. The turbulence ended when the airplane exited the clouds, and smooth air prevailed for the remainder of the flight. A flight attendant in the aft galley of the airplane reported that she was reaching inside one of the galley cabinets when the turbulence occurred. She reported that "the plane dropped, she went up in the air and when she came down, she landed on her ankle." The injured flight attendant called the captain on the intercom and reported her injury. The captain asked her to try to reach the jump seat and strap in, which she did. An uneventful landing was made at MSY. The flight attendant was transported to a local hospital. The injuries to the flight attendant were initially reported as minor. Three days after the occurrence, the NTSB learned that she had sustained "a broken distal fibula that was displaced." ## Aircraft - 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 - Engines: Cfm CFM-56 20000 lbs thrust turbo jet - Damage: No damage - Flight: Part 121 - Registered owner: Southwest Airlines Co. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, June 24, 1999 - Departed: HOU, HOUSTON, TX - Destination: MSY, NEW ORLEANS, LA - Flight plan: IFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; airline transport, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 14,000 total, 8,000 in this make and model, 9,200 as pilot in command, 240 in the last 90 days, 95 in the last 30 days, 6 in the last 24 hours ## Weather - Conditions: Instrument (IMC), Day - Wind: 70° at 5 knots - Visibility: 2 statute miles - Lowest ceiling: 800 ft overcast - Temperature: 73 °F, dew point 73 °F - Altimeter: 29.00 inHg - Observed at: MSY, 125 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 19990625043779A](https://openairdocs.org/incident/19990625043779A), Jun 25, 1999: Boeing 7373H4, Lafayette, LA, No damage. (-23) On June 25, 1999, at approximately 1945 central daylight time, a Boeing 737-3H4 transport airplane, N650SW, operating as southwest airlines, flight 1257,… ## Other investigations on N650SW (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 DCA11CA014](https://openairdocs.org/ntsb/DCA11CA014), Dec 18, 2010: Boeing 737-3H4 (N650SW), Philadelphia, PA, minor damage. Probable cause: the failure of the ground operations personnel to maintain awareness of the relative position of the two airplanes. 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.