What was found
IAD/MHT - FLT 6388 - DURING CLIMB AT 0735 HOURS ON 8-15-97, MADE AN UNSCHEDULED LANDING DUE TO RT TORQUE FLUCTUATION AND ROLLED BACK ON TAKEOFF FROM 78 PERCENT TO 55 PERCENT. AIRCRAFT RETURNED TO GATE WITH NO FURTHER PROBLEMS. MAINTENANCE INSPECTED AND COULD NOT DUPLICATE PROBLEM. AIRCRAFT WAS FERRIED TO LYH FOR TROUBLESHOOTING. MAINTENANCE CLOSED OPEN SDR BY REMOVING AND REPLACING RT ENGINE. OPS CHECK OK, AIRCRAFT RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)