SAS, not saying that the PBA needs to be a big deal, and certainly not upset the aircraft. But it is something that could catch the unwary out, if they just set attitude and power, get a good safe climb and speed, then move to other tasks, without an upper mode in. In the context of the accident discussion, with a pilot who did not use the AFCS much, the lack of familiarity and confidence to engage an upper mode is clearly a contributor to the accident.