Jamie,
sorry for the ambiguity, with "the lad is just 18 and needs his 4 and a bit years to even become licensed." If you give the CAA ELGD a looking over you will see that there are a number of options/routes into becoming an engineer.
While there are exceptions to the rule, special courses, apprenticeships etc, there is a requirement to demonstrate four and a half years experience on aircraft and be over 21 years old. Like I said there are exceptions, some courses require less practice experience, list options go on.... coming back to my original post, to clarify... were you to decide for any number of reasons to go down the military route you would get your time on spanners, however due to changes in the regulatory standard when coming into the commercial sector from the military as well as having passed all your exams you would need one years experience from the commercial sector.
As for your question about availability of jobs... well I don't know any licensed engineers who are out of work that are willing to move about, and that is something that you may want to consider if you want to enter the Helicopter world.
Aberdeen is "fairly" stable a place to work with it's cycles of people moving hangars, changing overalls and the occasional cycle like we have just seen where people have been made redundant, but it is probably the most stable market of size in the UK. However moving job normally means moving house as a helicopter engineer, or working away from home. This may sound a bit like the "you should start a pensions" lecture, and at 17 it may not mean a lot to you but at some stage in your life you may meet someone nice you want to live with; all this means you may end up working away from home, or moving home with every job change.
All that aside, its not a bad job and can be a great deal of fun.