As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
OIL CAP WAS NOT FULLY ENGAGED IN OIL TANK CAUSING LOSS OF APPROX 6 QUARTS OIL DURING CLIMB OUT. DISCOVERED OIL CAP UNLATCH ASSIST SPRING HAD DISENGAGED FROM HOLE IN CAP LATCH BAR. THIS ALLOWED OIL CAP LOCKING TAB TO LOCK WITHOUT OIL CAP FULLY ENGAGED IN OIL TANK. INSPECTED SIX ENGINES AND FOUND TWO CAPS WITH THIS SPRING AND FOUR WITH A SPRING DESIGN WHICH WAS BENT OVER DURING MFG TO PREVENT DISENGAGEMENT. NO OIL CAP PN CHANGE OR SB FOUND FOR CHANGE. REPLACED BOTH OIL CAPS.