5" crack in a 16" cymbal... Your not looking too good, but don't despiar there's a few things you can do to get some use out of it.
Once a cymbal cracks it is impossible to fix. Period. You can drill it then cut the crack etc. and it can prolong the life of the cymbal, but it will change the sound, so is not technically fixing it. This is not a bad thing though, my favourite ride is an old paiste Rude that had a 1 & 1/2" chunk taken out and it sounds amazing.
This technique has far better results on larger cymbals too .i.e 18" +, you take a piece out of a 16" crash that doesn't have that much mass to begin with...? 20" crash - different story.
A cracked cymbal is a great excuse to be creative and experiment with making some interesting effects cymbal, here's some things I've tried:
1) Turn it into a chime/bell. Think Gavin Harrison and those little chime things he uses. Get in their with some good cutting tools and basically just leave the bell and you got yourself an interesting little effects cymbal.
2) Cutting the cymbal down to from 16" to say 10". Dependent on how thick the cymbal was to begin with you'll end up with something sounding like a Will Calhoun 'Alien Disc' makes for someinteresting effects by itself, but I would get that modified 10" crash/disc and stack it in a 12" or 14" china, or put a 10" splash on it for some interesting mini hats.
3) Cut the crack out, or put holes in it like a Sabian Evo crash, then put some rivets/washers/anything! in the deformed result. You'll get a real nasty 'white noise' cymbal. Dirty, nasty, awesome. As long as the result sounds good to your ear.
So don't chuck that wrecked cymbal away, get all mad scientist on it and turn it into something interesting and new.