Incident Details
The aircraft was 38 miles from the destination airport when the captain notified the flight attendant to be seated due to the possibility of encountering turbulence. After completing the approach checklist, the flight attendant was given the signal to perform the final cabin check. At 9 miles from the airport, the flight encountered a single strong windshear, which caused the flight attendant to be thrown against the ceiling and then to the floor.
At the time of the occurrence, the airplane was operating within a weak Level I weather radar return, within 6 miles of a Level II return, and within 9 miles of a very strong Level IV return.
Operator Procedures
The operator's Flight Operations Manual states that the captain will advise the flight attendant as to whether he or she should be seated with the seatbelt fastened. However, neither the Flight Operations Manual nor the Flight Attendant Manual provided any instructions regarding when the flight attendant should resume duties after being told to be seated, nor was the captain instructed to notify the flight attendant to resume duties.