As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FIFTEEN MINUTES INTO THE FLIGHT, THE NR 1 ENGINE EXPERIENCED A MOMENTARY POWER LOSS OF ABOUT TEN PERCENT TORQUE. ALL THE GAUGES INDICATED THE SAME AND THE ACFT YAWED IN THAT DIRECTION. THIS LASTED ONLY A SECOND OR TWO, BUT A FEW MINUTES LATER THE SAME THING HAPPENED. AT THIS POINT THE ACFT RETURNED TO BASE. ON THIS FLIGHT IT HAPPENED A TOTAL OF THREE TIMES.