Outwest : I don't think the REAL cause has been identified or at least I can find no reference to it.
Why did the titanium stud break in the first place? Over torquing during installation? Harmonic vibration? What are the pros and cons of steel over titanium and vise versa?
I think Outwest was onto something but the normally secretive Australians are being true to stereotype. What was the cause of the Broome incident stud failure? Did they break one or two studs? Did they fatigue slowly and progressively or snap without prior indications? Have any of the 600 or so titanium studs being removed now showing any sign of pending failure?
The MGB has a max oil pressure of only 130 psi, the three studs to hold the filter body on should be plenty for that. Probably even Canadian Tire bolts would be fine.
BTW, an AD may be out tomorrow calling for grounding until they are replaced. So far it is just the TSB (Canadian Transportation Safety Board) that has grounded Canadian S92. In the meantime some operators outside of Canadian jurisdiction are grounding their fleets, some aren't.