Southside
It would appear that you have confused too issues here. If you are talking about officers leaving then this is by PVR (not by NGR) where the Services can set the waiting times to suite the manning situation at the time. The same applies to the RAF where several cadres (including airmen) have a waiting time of 12 months and many have shorter waiting times. As the Gorilla states this is something offered by the Services - it is not a right.
Details on NGR arein AP3392 Vol2 Leaflet 708
GENERAL RIGHT TO GIVE NOTICE
1. This leaflet gives guidance on the submission of applications to the RAF PMA for termination of regular RAF service on giving 18 months notice; see QRs 584(3) and (4).
2. All Engagements. Personnel serving on any type of engagement have the right, on completion of 9 years reckonable service, or at any time thereafter, to give 18 months notice to terminate their regular RAF service. The earliest time at which this right can be effected by giving notice at the 9 year point is therefore, on completion of 10½ years reckonable service. Previous regular whole time service which is reckonable in accordance with QR 3017 will qualify for inclusion when reckoning the length of service necessary to determine eligibility to give notice. Previous service will not however, release personnel from any reserve liability if the engagement on which they are currently serving includes a period in the reserve.
3. Notice Engagements. Personnel serving on Notice Engagements have the right, exercisable at the end of 18 months formal notice, to be transferred to the RAF Reserve of Airmen on completion of 3 years service from the end of basic trade training, or at any time thereafter, and to be given a free discharge at the end of 6 years service in the Reserve.
Note: Personnel who enlisted into the Royal Air Force on a Notice Engagement and who subsequently extend their service retain the right to give notice even though their terms of service change as a result of accepting an offer of further service.
Technically, the Trg RoS is not to amortize the costs of training. Amortization means to pay back the monetary value of the course; however, it is near impossible to ascertain the exact cost of an individuals aprticipation on an MOD course (there are differing views on where the boundaries of the costs should be drawn). Trg RoS is set at a level that takes into accounrt of both the invsestment placed in an individual (not just in monetary value) and the value of that trained individual to the system. This is why, for insitance, the Army graduates of Islander training have a longer Trg ROS - the comprise such a small cadre of individuals that the Army percieved that that trg justified a longer ROS.