As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(AUS) RT ENGINE EXPERIENCED 20 PERCENT TO 30 PERCENT TORQUE DROP WITH ASSOCIATED EGT FLUCTUATIONS. MAINTENANCE INVESTIGATION COULD NOT FIND ANY FAULTS AND ENGINE PARAMETERS WERE NORMAL. AIRCRAFT RETURNED TO SERVICE. (CASA NR 510001937)