As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE ACCOMPLISHING TSR815527, FOUND NR 1 BLEED AIR REGULATOR CRACKED AT CONNECTOR ATTACH. ACFT GROUNDED. REPLACED NR 1 BLEED AIR REGULATOR. OPS CHECKED GOOD. REF MM 36-11-03. IAW TSR EXISTING FAULT ON INITIAL EVALUATION 47-30027 WAS PRESENT. STEPS 1-3 ACCOMPLISHED. REPLACED NR 1 PRECOOLER CONTROL VALVE SENSOR, LEAK CHECK GOOD.