What was found
EN ROUTE TO TOL, DURING CRUISE, THE NR 1 ENGINE LOST OIL AND QTY WENT TO ZERO. SHUT DOWN ENGINE AND DECLARED AN EMERGENCY. THE AIRCRAFT LANDED AT TOL WITHOUT FURTHER DIFFICULTY. FOUND A BAD HELI-COIL FOR A GEARBOX FITTING. INSTALLED NEW HELI-COIL AND CHECKED ENGINE OIL FILTER. FILTER FOUND TO BE CLEAN. RAN ENGINE AND NO LEAKS WERE NOTED. THE AIRCRAFT WAS RETURNED TO SERVICE. (M)