At VS the process seems a little more straightforward than others reported here. Currently, once a pilot has 6000 hours, including at least 1000 hours in Virgin (realistically it'll be at least 9000TT with at least 5000 in Virgin), and the appropriate seniority, he or she will be assessed in absentia by a command board. If found suitable after a perusal of trainers' reports, the candidate will be invited to complete 3 Pre-Command Assessment simulator sessions, which are complex LOFT scenarios. Success at PCA puts them in the waiting list for a command course, which is 20 LHS longhaul sectors. No groundschool, but lots of in-seat examination.
The system is due to change slightly in that a First Officer Development Programme is being instituted in which FO's will receive an extra, assessed, LOFT sim each year. As they approach the seniority for command, the Command Board will decide whether their performance in the FODP justifies them being entered for Command Training. Whether there will be any kind of PCA I don't know. There is a move afoot to reduce the number of sectors in command training, as, it is considered, the experience levels of our new commanders is such that they should be quite capable of doing the job from the off. However, it would be nice to see some groundschool that covered the legal responsibilities of a commander and went into more detail about the various trades that support the flying operation.