With regards to the difference between CTC and pay to fly, if you go back a year then it would seem there was a big difference; with CTC you were pretty much guaranteed a full time job after the 6 months so it can perhaps be described as a sponsorship scheme as such, or maybe 'pay to train, be paid to fly' .
Now however, if the line training only lasts 6 months, then yes it appears it is effectively pay to fly; however, it has been argued that there aren't many places where you can get a fully accomodated fATPL, MCC, Advanced handling, TR and 6 months line training for £47500 (bond minus funds returned)?? Or maybe you can, I haven't done enough research to have a valid opinion on that, am working on the basis that Ryanair for example demand £20,000 for TR alone (not accomodated). And note the IF, there haven't been enough 6 month only placements to demonstrate this is now the norm.
I don't think BALPA would be of much help in this instance? Needs to be some sort of independent attempt?