Investigation brief · generated 2026-10-09 · source: NTSB public docket and accident database
BOEING 737-7H4 — Laverne, OK, USA, 2012-03-20
NTSB number
WPR12LA144
Operator
SOUTHWEST AIRLINES CO
Registration
N247WN
Highest injury
Serious injury
Regulation
Part 121
Damage
—
Cohort
Part 121 airline
Recorder data
Tier 1 — decoded recorder tables
Every sentence below is taken directly from NTSB records — the accident database, the docket's recorder reports and the Board's findings — with its source noted. Nothing is paraphrased or inferred.
NTSB summary
The flight had been experiencing moderate turbulence along its route. Once the turbulence had subsided, the seatbelt sign was turned off. The flight attendants had resumed their service when the flight encountered three additional turbulence jolts. The aft galley flight attendant was trying to get seated and strapped into the jumpseat but was injured when another turbulence jolt occurred. She was thrown across the galley and hit her back/ribs on an object. Flight data recorder information showed that vertical accelerations fluctuated between about 0.75 g and 1.2 g; lateral accelerations also fluctuated during this period, between about +/- 0.05 g. An airmen’s meteorological information advisory for moderate turbulence was active for the accident location at the time. A significant meteorological information advisory for occasional severe turbulence was active for an area west of the accident location.
The airplane’s encounter with severe turbulence during cruise flight, which resulted in a serious injury to a flight attendant.
Verbatim, NTSB determination.
Sequence of events (FDR factual report)
Time
Event
Page
05:45
Figure 1 basic parameter plot begins, covering entire flight through landing at 10:05
3
shortly after departure
Aircraft climbed to flight level 380
3
08:24
Winds aloft speed calculated by the FMC was about 140 knots from about 160 degrees true
3
08:22 to 08:28 (about 5-6 minutes)
Vertical accelerations fluctuated between about 0.75g and 1.2g; lateral accelerations fluctuated between about +/- 0.05g
3
08:27
Aircraft descended from flight level 380 to flight level 340
3
08:27:15
Shortly after starting a descent to flight level 340, the fluctuating accelerations decreased significantly
4
after descent to FL340 (approx 08:28 onward)
Fluctuations in vertical and lateral accelerations decreased, fluctuating between 0.997g and 1.004g and +/- 0.01g, respectively
3
08:38:20
During otherwise decreased vertical and lateral accelerations at FL340, the vertical acceleration varied from about 0.255g to 1.7g within a 1 second period of time
3
08:38:20 (1 second period)
Elevator surface deflection varied between 2.78 to -5.07 degrees; rudder surface varied between about -1.5 and 1.8 degrees
4
about 15 seconds after 08:38:20
Altitude hold mode was disengaged and the aircraft began a descent to flight level 320
4
about 20 minutes after 08:38:20
FMC calculated a decrease in winds aloft at flight level 320 to under 30 knots for about 12 minutes; during this period the winds aloft shifted from about 160 degrees true to 340 degrees true
4
08:17:15 through 08:30:45
Expanded scale plots (Figures 3 and 4) show aircraft at FL380 experiencing fluctuations in vertical and lateral accelerations for about 6 minutes from 08:22 until 08:28
4
08:35:30 through 08:42:00
Expanded scale plots (Figures 5 and 6) show the time period around the 0.255g to 1.7g vertical acceleration encounter at about 08:38:20
4
Extracted by claude-sonnet-5; 0 of 1 stated events verified against the raw recorder data.