As the subject reads, how common is a person to not check out of a stream and then re-apply and get into another stream? Or is it a one and done situation usually?

I would really like to know if that situation already happened to someone here, because i'll try to re-do the process after my unsuccesful phone interview, i Know i got the potential to land a career with Nav Canada. Still some hope if somebody can confirm that re-doing the process was sucessful for them.

Do some digging through the forum here. There are definitely people who have made it through to a course offer on their second or third try.

I think 2 different things are being talked about here. It sounds like the OP is asking about people who go through training and get CT'd. In that case, it is not uncommon to be offered an opportunity somewhere else. Often that opportunity will be in the same stream (another Tower for example) but not always. If you do switch streams, you need to first complete the basic course of the other stream, which means more training resources for the company and a longer training time for you. Being CT'd, not being offered another opportunity within a couple of months, and then re-applying successfully down the road would be quite rare.

Not being successful in the initial application and then re-applying successfully is fairly common. If you don't progress at any stage or time out, and you're still interested, just keep applying and eventually you might get a chance.