As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSING THROUGH 39600 FL ENG NR 4 FAILED AIRSPEED .79M DESCENDED TO 30FL AND RESTARTED WITH NORMAL OPERATION AFTER RESOLUTION. FOUND VSV OUT OF RIG. RIGGED NR 4 ENG VSV AND VBV PER MM 73-21-10. REMOVED AND REPLACED ENGINE DRIVEN FUEL BOOST PUMP (NASH) PER MM 73-10 RAN ENG NR 4 PER JRH MPA ALL OPS CHECK GOOD, NO LEAKS NOTED.