As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
GEAR UNSAFE LIGHT REMAINED ON AFTER TAKEOFF WITH GEAR HANDLE IN THE UP POSITION. ALSO HAD THE HYD PRESS LIGHT, RAN THE CHECKLIST AND THE RT MAIN DROPPED FIRST. ALL 3 GEAR LOCKED AND LANDED WITHOUT INCIDENT. FOUND LARGE AMOUNT OF SAND TYPE MATERIAL ON ALL MLGS, RT UPLOCK ROLLER COVERED ALMOST COMPLETELY. CLEANED MLG LIFTED ACFT OPERATED MLG 7 CYCLES WITH NO DEFECTS NOTED OPS CHECKED SAT IAW MM 7-10-01 AND 32-01-00.