As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORTED RT PACK SHUTOFF WHEN BLEEDS TRANSFERRED FROM APU TO ENGINE. CREW RETURNED TO FIELD AND LANDED WITHOUT INCIDENT. MAINTENANCE TROUBLESHOT, R & R RT AIR CONDITIONING PRESSURE REGULATING AND SHUTOFF VALVE AND PERFORMED CHECKS IAW AMM. ACFT RELEASED FOR SERVICE.