Ah, right, break a leg.. Somehow didn't occur to me since I hardly use or hear that saying.. lol.. must be getting old.
Dake, I haven't got in yet la, don't jinx it la..lol.. I'm still jumping the hurdles to get in. Not sure I'll make it through all the way yet.
And yes, it is definately possible, and has happened in SIA, MAS and AA where cadets get ejected from the training programme. You usually get ejected for not being able to pass the exams, and well, if you're not fit to fly. There has been cadets that don't keep the proper discipline and study when they should, and resulting them in failing exams. It's written in the contract that if you fail to observe the company's regulations (usually means you have to graduate in the duration stipulated to you), the company can terminate your contract. In MAS, you'd even have to pay back MAS for the fees that was incurred. There seems to be a number of cabin crew/ground crew in MAS whom had failed the programme and now serving MAS under a different capacity. Of course if you commit a crime, say for robbery, you still can be sacked by the company.
In SIA, as I was told, some got terminated because they couldn't fly. This was because they suffer from air sickness. In this case, they just terminate your contract as its due to health reasons. Some got terminated because of failing exam papers which they expect you to pass.
It's not an easy thing being a pilot. Even once you finish flying school, there's a whole bunch of exams to go through before going 'online', meaning, to fly the actual commercial jet. You'd have jet conversion, type ratings and every 6 months, go through a basecheck. This career is perpetually about keeping you on your toes. It's by no means an easy career, because if you fail these exams, you'd be reviewed by the company's flight operations and can be sacked. That's not even mentioning the annual medical you go through. You fail that, you loose your license to fly. You even need to know how to swim and save passengers in an event to ditching an aircraft. You fail that, you're not fit to fly. Scary? Well, this is the job of a pilot. You can say this is an exam-oriented career, and if you're not prepared and don't keep on your toes and slack away, your career as a pilot won't last long.
Sorry for the dramatic paragraph, but this is what pilots go through.
I think forumer m732 could tell you more with what he does. I think he should be a First Officer by now.