19990302016819I

(-5)On March 2, 1999, while climbing in the vicinity of the carleton VOR, Michigan, 3 of the four flight attendants in the extreme aft portion of united airlines flight 648 were thrown up to the ceiling and then fell to the floor of the passenger compartment. One of the flight attendants received minor injuries as a result. While in a normal climb to 35,000 feet and approaching the point at which a normal level off would be commenced, the mach number rapidly accelerated from .80 to approxiamtely .85 accompanied by a 2000 foot per minute rate of climb. The copilot, who was the pilot flying at the time, disengaged the autopilot, reduced the rate of climb and leveled the aircraft at 34,800 feet in what was described by the captain as a "smooth" recovery. The aircraft was then climbed normally to 35,000 feet and proceeded to destination without further incident. There was neither a forecast for turbulence nor were there any pirep's reporting any unusual flight conditions. The climb to altitude was normal with no turbulence prior to the incident event and the seat belt sign had been extinguished.