As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON PREFLIGHT CREW NOTICED LT ENG OIL DIPSTICK WAS DETACHED FROM FILLER CAP ASSEMBLY & NOT VISIBLE INSIDE FILL TUBE. MX RETRIEVED OIL DIPSTICK FROM INSIDE OIL TANK. LATEST CONFIGURATION OIL FILLER TUBE & DIPSTICK ASSEMBLY WITH BALL CHECK VLV INSTALLED IAW SB 72-13487. ENG SERVICED WITH OIL. LEAK CHECK PERFORMED. ACFT WAS RETURNED TO SERVICE.