As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION ON LOWER RIGHT HAND TCAS ANTENNA AREA ***AIRCRAFT REMOVED FROM SERVICE*** REMOVED CORROSION AT LWR R/H TCAS ANTENNA AREA, 5.5"L X 2.20"W X 0.008"D. IN LIMITS IAW ASAP EA# AWAC CRJ253-01583 REV IR DATED 3/8/2021. HFEC INSPECTION PERFORMED WITH NO INDICATIONS.