As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
QRF TO THE ORIGIN AIRPORT DUE TO BLEED TRIP OFF ENGINE NUMBER ONE LIGHT ILLUMINATES. QRH APPLIED BY CREW AND FAIL RECURRENT AGAIN. RETURN REQUIRED.CORRECTIVE ACTION: WAS REPLACED PRECOOLER CONTROL VALVE SENSOR IAW AMM 36-12-03/401 AND REPLACED 450 THERMOSTAT IAW AMM 36-11-05/401. IN TEST NORMAL.