What was found
DFW - FLT 9898 - TRAINING FLIGHT, ON APPROACH TO DFW, RT OIL PRESSURE DROPPED INTO THE CAUTION RANGE. CREW CONSULTED QRH AND FEATHERED ENGINE. OIL PRESSURE CONTINUED TO FALL AND ENGINE WAS SHUT DOWN AND SECURED APPROXIMATELY 10 MILES FROM DFW. AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED RT ENGINE AND FOUND OIL 5 QUARTS LOW. NO SIGNS OF OIL LEAK WERE IDENTIFIED. ENGINE WAS SERVICED WITH 5 QUARTS OF OIL AND GROUND RUN TO DETERMINE IF LEAKING. NO SIGNS OF LEAKAGE FOUND. AIRCRAFT RETURNED TO FLIGHT TRAINING STATUS. PART TOTAL CYCLES, 9,255.