As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION ON MLG HYD LINES SUPPORT PLATE (IN BK, LG EXT, LG RET) AT LH RH W/W MLG. MLG HYD LINES SUPPORT PLATE (IN BK, LG EXT, LG RET) P/N: CC670-10337-1 AND P/N: CC670-10337-2 AT L/H R/H W/W MLG WERE REPLACED PER CRJ900 AMM 20-21-00-910-801-A01