United Airlines flight 963 encountered convective turbulence while descending into Newark Liberty International Airport (EWR), Newark, New Jersey. As a result of the turbulence, one flight attendant (FA) sustained serious injuries and three sustained minor injuries. The aircraft continued to its destination without further incident. The flight originated at Berlin Brandenburg Airport (BER), Berlin, Germany. The flight crew reported that before initiating the descent, they briefed threats to the approach and arrival phase of the flight and noted pilot reports (PIREPs) in the area of light to moderate turbulence, including a turbulence report from a previous aircraft that had reported turbulence during the descent. The flight crew stated that the Purser was advised to expect turbulence during the descent, and they recommended that the cabin crew complete their duties sooner than normal. The seatbelt sign was illuminated for the descent. A significant meteorological information (SIGMET) for moderate turbulence was in effect between 20,000 and 30,000 ft altitude valid from 1200 -1600 local time across the area of the flight’s descent. A previous SIGMET had been in effect from 0900 ? 1200 local time for the same altitude range. Additionally, there were numerous PIREPs of light and moderate turbulence between 21,000 and 29,000 ft across much of New York state into northern New Jersey in the hour before the accident. The flight crew stated that while level at 23,000 feet altitude and just past the Albany very high frequency omnidirectional range (VOR), they received clearance to descend to 16,000 ft altitude. They were clear of clouds in smooth air above a much lower broken layer of clouds. At 22,500 ft altitude, the airplane began an uncommanded roll to the right of about 45ø, followed by an uncommanded roll to the left of about 45ø. The pilot flying stated he corrected for the roll with aileron control and reduced thrust to slow the airplane below turbulence penetration speed. The Relief Officer made a ?flight attendants take your jump seats’ announcement, followed immediately by ?flight attendants be seated immediately’ announcement. The flight continued the descent in light to moderate turbulence for about a minute. After the event the Relief Officer asked the FAs to check in, the Purser reported that there were FAs with injuries in the aft galley in need of medical assistance. No passengers were injured. The flight crew contacted Newark operations via VHF to ensure that they were aware of the situation and to request that paramedics meet the airplane upon arrival. The flight landed at EWR uneventfully and an injured FA was transported to a local hospital and was diagnosed with a broken clavicle and punctured lung. Probable Cause: An inadvertent encounter with clear air turbulence during descent.