What was found
PILOT REPORTED THAT HE WAS NOT GETTING A DOWN AND LOCK INDICATION ON LEFT MAIN. AFTER HE WAS ON GROUND, INSPECTION REVEALED THAT THE LEFT RETRACT ARM PN 42042-000 WAS CRACKED AND SEPARATED SUFFICIENTLY ENOUGH TO PREVENT THE DOWN LOCK SWITCH FROM CLOSING. REPLACED RETRACT ARMS ON BOTH SIDES OF ACFT, AFTER LEARNING OF PIPER SL 1092C.