What was found
SEA - AFTER SELECTING "GEAR DOWN" ON APPROACH, THE RIGHT MAIN GEAR INDICATED AMBER DOOR OPEN AND RED GEAR UNSAFE SITUATION CONTINUED FOR 60- 90 SECONDS AND THEN INDICATED GREEN. ALTERNATE EXTENSION CHECKLIST ACCOMPLISHED AMBER RE-ILLUMINATED DURING ALT EXTENSION CHECK LIST. LANDING UNEVENTFUL. RIGGED RGDLK1 PROXIMITY SENSOR IAW AMM TASK 32-61-06-830-801. PERFORMED OPS TEST OF THE PRIMARY EXTENSION AND RETRACTION SYSTEM IAW AMM TASK 32-31-00-710-801. PERFORMED OPS TEST OF THE ALTERNATE EXTENSION SYSTEM IAW AMM TASK 32-34-00-710-801. OPS CHECKS GOOD, NO FURTHER DEFECTS NOTED. RETURNED TO SERVICE. NO PARTS REPLACED.