"You would think Sikorsky would have been really focused on all the ways oil could be lost, especially the appendages, like the filter among others"
squib66,
The problem is not just with Sikorsky, it happens at Rolls-Royce too. Structural failure in an oil system component is apparently the root cause of the catastrophic uncontained turbine failure on the Qantas A380's Trent 900 engine.
riff_raff