What happened
The flight crew announced the possibility of turbulence to passengers and crew members during the aircraft's descent and final approach phase. Despite this warning, there were periods of relative calm where cabin attendants felt it was safe to leave their jump seats and perform their duties.
While the cabin staff were attending to their tasks, the aircraft encountered intermittent jolts of rough air. Two of the attendants were not secured in their seats at the time of these encounters. The sudden movements caused by the turbulence resulted in injuries to both individuals. Despite these incidents within the cabin, the aircraft successfully completed its landing at Washington National Airport without any further complications or safety issues.
Findings
The primary contributing factor to the injuries was the failure of two cabin attendants to remain buckled in their seats during a period when turbulence was anticipated. Although the possibility of turbulence had been announced, the lulls in the activity created a false sense of security, leading the crew members to neglect safety protocols regarding restraint systems until rough air was actually encountered.