As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IAD/ORF - FLT 6489 - DURING TAKEOFF AT 1630 HRS ON 4-21-96, ABORTED TAKEOFF DUE TO THE HEADING COMPUTER SHOWING ERRORS. AIRCRAFT RETURNED TO GATE WITH NO FURTHER INCIDENTS. MAINTENANCE RERACKED THE NR 1 AND NR 2 AHRS. AIRCRAFT WAS RELEASED AND APPROVED FOR RETURN TO SERVICE. (X)