As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 4 ENGINE OIL PRESSURE LOW LIGHT ILLUMINATED ON DESCENT. OIL PRESSURE READ 30 PSI. THROTTLE WAS IN IDLE. SHUT DOWN NR 4 ENGINE. WINDMILLING OIL PRESSURE WAS 3 PSI. REPLACED OIL PRESSURE RELIEF VALVE IAW PRATT AND WHITNEY MM 72-00 AND ADJUSTED OIL PRESSURE. GROUND RAN ENGINE, OPS CHECKED GOOD.