These are Aircraft Maintenance Mechanics, or FLMs of old.
A common misconception which has led to most of the AMMs being criminally underemployed on their 1st tour. Even their SNCOs didn't (and possibly still don't) understand that although streamed as Av or Mech, they all did the same AMM course. As well as flight line training, they covered both Av and Mech 1st line maintenance tasks (replacing batteries, igniters, oil filters, LRIs etc), and because of this they will retain 1st signature capability in both trades throughout their careers.
Instead of being given the opportunity to assist the trade desks, developing their own skills and knowledge (SAKS?) and becoming a productive tradesman, most were treated as line swine. You can't complain down the line when they are your new Cpls and no effort has been invested in them.
Leave Cosford as LACs and are advanced to SAC upon completion of TATs.
And their TATs consisted of.....becoming Line trained! An object lesson in sending out all the wrong signals. Most of them may as well have gone back for FT after a couple of months.