As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AT CRUISE THE FLIGHT CREW NOTICED E1 OIL PRESSURE DROPPING INTO THE AMBER RANGE AND OIL QUANTITY WAS DOWN TO 3 QUARTS. THE QRH WAS FOLLOWED AND POWER WAS REDUCED TO IDLE BUT THE PRESSURE CONTINUED TO DROP INTO THE RED RANGE. E1 WAS THEN SHUTDOWN AS A PRECAUTION AND THE ACFT LANDED WITHOUT INCIDENT. THE O-RINGS ON THE AFT SCAVENGE SUMP MAGNETIC CHIP DETECTOR WERE MISSING. THE O-RINGS WERE INSTALLED AND THE ENGINE SERVICED WITH OIL WITH NO FURTHER DEFECTS NOTED.