darobstacraw
The PW4077 as used on the 777-200 is a unique sub-variant as it is the only one to use hollow titanium alloy fan blades (similar to many RR Trent engines).
The 744 case in Maastricht was a completely different failure mode and a different variant of the engine. It seems to have suffered some catastrophic turbine blade failure, for reasons yet unknown, but also contained.