As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG BURNING ODOR, AIR TURN BACK. DURING CLIMB OUT A STRONG BURNING ODOR WAS SMELLED THROUGHOUT THE ACFT. IT WAS ALSO NOTED THAT THE AIR CONDITIONING WAS ONLY DELIVERING HOT AIR TO THE COCKPIT & CABIN. THE DECISION WAS MADE TO RETURN, NO EMER WAS DECLARED. THE ACFT LANDED WITHOUT FURTHER INCIDENT. TROUBLESHOOTING DISCOVERED THE NR 1 PACK FAULTY. PART ORDERED. ITEM WAS DEFERRED.