As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO FIELD UNDER AMBER ALERT DUE TO FUMES IN THE COCKPIT. ODOR DISSAPATED DURING RETURN TO GATE. THE DETERGENT WASH OF THE ENGINES IS THE SORCE OF THE ODOR. PER MM 72-05-99 PAGE 701, ENGINE NEEDS HIGH POWER RUN AFTER WASH TO REMOVE ANY DETERGENT RESIDUAL FROM PNUEMATIC SYSTEM.