Old Grubber said: 'Secondly, the problems solved by having one force (RN) operating the aircraft to one set of standards and very importantly managing the logistic support in one way (RN) will increase the availability of spares that are common to MK1 and MK3 Merlins (lots)'......................................So thats why over 50% of the Mk1 fleet are on the ground for spares and snags at any given time. The logistics route is the same for both fleets. AW, DE&S and Defence transport. The only single service logs input is from the supply R&D or gang plank to the customer, with a bit of EMBAV thrown in for good measure. If you have no spares the logs route can be as good as its likes but still won't overcome the basic lack of spares issue. BTW there is only 45% commonality between the two fleets - not really lots - so thats not really a valid point as most of those are not the important 'makes it fly' bits. Lastly Mk3 is hugely complicated due to its integrated systems. Everything goes through two very clever but unreliable computers./ Its a pinkies nightmare when it starts playing up as it can report snags on 'S' systems and not report on U/S ones. I've worked both and SK is far simpler in almost all respects.