What is called Pipeline training for more technically specific ET Billets, "C" school is required in order to fullfill a qualification for that job. Most shipboard billets for ETs' require some form of "C" school. Even before you receive orders, you will be able to tell what schools are needed, by the billet number. Pipeline training, is usually done prior to shipboard report date. This is done, so that your pending schools and the unit's schedule do not conflict.
If for example, you are to report to Commsta Boston, you will not be attending any "C" schools prior to your report date. Although, there is a HF-80 Road Show, that comes by annually.
That is why I say it depends unit to unit. You need to wait to find where you are going.
Looks like there are three ET3 billets on a 270. One is tactical/weapons, one is comms, and one is nav.
If you fill the tac/weps billet, it is 99.99% certain that you will receive PCS orders to Yorktown for pipeline training BEFORE you report to the cutter. Most of these folks I work with go to OSS (optical sight) school later on after they have reported. Some also go to 2M school later.
I'm not a comms or nav guy so I'm not sure about those strands. Like smirfy said, I'd imagine they try to get as many pipeline schools as possible before reporting.
