What was found
(CAN) DURING LANDING THROUGH APPROXIMATELY 60 KNOTS, AIRCRAFT EXPERIENCED A COMPLETE LOSS OF 'A' SYSTEM HYDRAULICS. (NOTE: 'A' PUMPS ON WITH LOW PRESSURE LIGHTS ILLUMINATED - MAX 1.5 MINUTES) MAINTENANCE INSPECTION REVEALED POSITION NR 1 LOWER AILERON PCU FILTER HOUSING COMPLETELY CRACK AROUND CIRCUMFERENCE OF HOUSING (DETACHED FROM UNIT). MAINTENANCE REPLACED PCU PER MM 27-11-71, LEAK CHECK AND ADJUSTMENT TEST OF AILERON ACTUATOR COMPLETE. NO LEAKS TO REPORT.AIRCRAFT RETURNED TO SERVICE WITH NO FURTHER INCIDENTS TO REPORT.