On June 11, 1997, approximately 1135 mountain daylight time, a Boeing 737-291A, N980UA, operated by United Air Lines, Inc., as flight 441, sustained no damage when it encountered clear air turbulence while on descent to Albuquerque, New Mexico. One flight attendant was seriously injured, but there were no injuries to the airline transport rated captain and first officer, two other flight attendants, and 103 passengers. Visual meteorological conditions prevailed, and an IFR flight plan had been filed for the scheduled domestic passenger flight operated under Title 14 CFR Part 121. The flight originated at Denver, Colorado, approximately 1035. The following is based on information provided by a United Air Lines safety department spokesman. The airplane was descending through FL180 when the crew was advised of light to moderate turbulence. The captain instructed passengers and flight attendants to return to their seats and fasten their seatbelts. Shortly thereafter, the airplane encountered turbulence. Prior to getting into her seat and restraining herself, a flight attendant was injured when she struck her back against a seat armrest. Paramedics who examined her at the airport said she had sustained a contusion. The flight attendant continued in her duties on the return flight to Denver. She was later examined by her personal physician, and X-rays indicated she had fractured a bone in her shoulder.