Iver - from what was said at the Qatar Wings CTC open day they told us that an A320 FO position would last about 2-3 years, then you would move on to say an A330 for I'm not sure how many years as FO and then looking towards Captain after that... Of course it is too hard to say whether these time figures are correct but you certainly won't be locked in to the A320 forever. Those are the rough figures they gave us and it will be interesting to see how future cadets progress... I will be applying in February.