bmibaby 737's are capable of both Cat 3 and Cat 2 approaches. It is possible for a runway to be Cat 3 but NOT Cat 2 - I think Manchester 06L is an example of this. This is because at decision on a Cat 2 approach you are not over the runway where as on a Cat 3 (A) approach at 50ft RA you are actually over the tarmac. If the ground is uneven just prior to the runway it may not be possible to do a Cat 2. I do not however know the specifics for Cork.