As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT AND MEDICAL STAFF REPORTED A LOUD SOUND AND SUBSEQUENTLY SMELLED SMOKE. PILOT NOTED THAT THE AIRCONDITIONING SYSTEM WAS NO LONGER BLOWING AND THE C/B WAS TRIPPED. HE OPTED TO RETURN TO BASE WHERE MAINTENANCE NOTED THE AFT AIRCONDITIONER BLOWER HAD FAILED.