As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED SEVERE POWER LOSS WAS NOT ABLE TO MAINTAIN 100KTS. UNSCHEDULED LANDING AT THE CHALLIS AIRPORT, IDAHO (C53) MECHANICS INVESTED GATED ISSUE FOUND THE TURBO WAS LEAKING INTERNALLY, AND TURBO IMPELLOR WAS RUBBING INTO HOUSING. TT AIRFRAME 73.1 HOURS TT ENGINE 94.7 HOURS TURBO MANUFACTURE AERO FORCE.