Recently I've done a very hard track outing at the "Ring"...
Since then, my brakes make a howling noise when braking from speeds above 100 mph.
I have Prodrive discs and Pagid Bleu RS42 pads, half worn....
I checked the discs and pads and there are a few cracks on the half worn pads...
Could this be the problem or what else ??
There is also no problem with the wheel bearings or so...
The car brakes still very well, except from a slight judder and that howling noise.
Maybe it's time for a pad change or is this normal ?
I had it never heard before, but the brake shop where I bought the pads told me that Pagid pads a more noisier then the standard crap...

Creepy,....

you need to get any carcks in the pads looked at professionally as it is highly possible that this is causing the problem and it could potentially lead to other more serious issues (based on your post and not knowing how big, serious these cracks are!!)..........
it sounds like you have over-heated the pads and wouls be better of with a higher spec material.........
alyn - asperformance.com

The cracks are from one side to another, and there are also small pieces missing on the syrface of the pad. I bought this RS42 pads especially for track racing, that what they advised me. But I don't know if you can use them fully or if you have to replace them when half worn. I think they're good for 12500 miles now...

Creepy

Get the pads replaced , you don't want to risk life and limb on these pads. REPLACE THEM STRAIGHT AWAY.