What was found
AIR TURNBACK, AT APPROXIMATELY 80-85 KNOTS ON TAKEOFF ROLL, HEADING FLAG ON CAPTAIN'S HSI AND FO'S RMI WITH FILGHT DIRECTOR WARNING LIGHT ON CAPTAINS SIDE. FLAG REMAINED IN FIEW ENTIRE FLIGHT. APPROXIMATELY 5 DEGREES DIFFERENCE IN NR 1 COMPASS VS NR 2 COMPASS AIRCRAFT RRETURNED TO AMS, 24,000 KGS OF FUEL DUMPED. FOUND WIRE SHORTED TO GROUND W153-1F263-22. REPLACED WIRE FROM D1166P TO TX214H26 AND REPLACED COMPAS COUPLER IAW MM 34-12-00 SATISFACTORY. ALSO, REPLACED INU NR 1 AND NR 3 ACC MM 34-41-03 P/N 7886580-011. REPLACED CIWS COMPUTER ACC MM 34-44-01 P/N 777-1826-004. REPLACED CAPTAINS HSI ACC MM 34-41-06 P/N 2592639-901. ALL OPERATIONAL CHECKS SATISFACTORY. (M)