Waiting for the smartarse to retort anything different!!
Not a smart arse but with over 30 years in the industry hopefully a bit of experience.....
Four years from zero to a type rating/company approval may have been possible but is very unlikely in the current climate unless you are extraordinarily switched-on and find the right employer!
A more realistic timescale for an Ab-Initio would be two years classroom work with "very limited" hands-on experience that these type of courses offer. Then, two years “suitable” maintenance experience (if you then can manage to find an employer!) Bear in mind that during the two years "on the tools" you will need to learn a massive amount that the books didn't teach you, build your confidence and knowledge of how complex modern transport aircraft are maintained.
Whilst you might then persuade the CAA into issuing you a License after four years from starting, most airline employers would expect far more "hands on" maintenance experience before issuing a full B1/B2 company approval (which is when you start to reap the rewards for all the hours of studying etc!) Apart from holding an appropriate type rating, you will need to show that you are experienced and capable of making important decisions affecting the airworthiness of an aircraft.
Be aware that the "A" License is now heavily used by many Airlines/MRO's to save money (particularly in Line Maintenance) You may be given the opportunity to start Certifying this way with limited & simple tasks and then gain a B1/B2 approval as vacancies open up and you prove your suitability.
Either way, in my experience (major UK Airline) I would say a realistic timescale from starting to a full type approval on an airliner is more likely to be in the region of 7 - 8 years.
Hope this helps
