Boeing 737-724 N16709 accident near Winnie, Texas

Probable cause

the flight crew's penetration of a rapidly developing thunderstorm cell in an area of forecasted convective activity. The serious injuries were the result of a misunderstanding between the captain and cabin crew regarding the potential for turbulence.

NTSB analysis

The flight encountered an area of severe turbulence during the climb at about flight level 221 on departure that seriously injured two flight attendants (FA). The flight crew was aware of the forecasted convective conditions and potential for turbulence forecast along their route of flight. The captain and FAs differed in their recollection about the turbulence discussion during the pre-flight briefing. The FAs were not aware of the turbulence potential during the flight and began their service before the captain instructed them as he intended. The weather radar tilt setting of +1 degree used by the flight crew would be useful for detecting the tops of medium range and distant storms but would not be useful in detecting the rapidly developing nearby cells below and in front of the airplane. A negative tilt setting on the weather radar was recommended by the company to detect cells building in front of the airplane. As a result, the flight penetrated a rapidly developing area of "extreme" convective activity that produced severe convectively induced turbulence.

Text from the NTSB. Open the NTSB docket for DCA12LA091 for the full record.