The same thought crossed my mind when I saw the C-27J at the 2008 Farnborough show.
If not for line transport, but a few for Special Forces support, a role which some C-130's do now and where a smaller payload is not so important.
So these C-27J's would release some C-130's for regular line work.
Of course, apart from the usual budget issues, it would be another type in service, along with C-17, C-130K/J, A400M.
That will no doubt have caused plenty of adverse comment at the Treasury, who fought hard to resist the original C-17 4 aircraft lease.
What has happened is that in the mid 1970's, the RAF had VC
-10's, C-130's, Andovers, Belfasts, Britannia's and some Comet 4's.
These were largely a legacy of the time when the UK maintained substantial garrisons in Singapore, Borneo, Hong Kong, Bahrain, Malta, Gibraltar and a mini tactical air force in Cyprus.
Between 1971-78 these largely disappeared, or in the cases of Hong Kong, Gibraltar and Cyprus, were reduced in size, most went in 1971 with some presence in Singapore and Malta until 1976 and 1978 respectively.
Staging posts to support these, such as Gan in the Indian Ocean went too.
What this did was to focus more heavily on the primary Cold War role in Europe, mostly Germany, with forces also to quickly deploy to the flanks such as Norway and the Mediterranean.
Starting to re-build UK air defence, the RN
staying around the same size but now an Anti sub force in the Eastern Atlantic with again, some amphibious capability for those NATO flanks.
So the result of this was that the RAF transport fleet was rationalized, they had a large (60+) and fairly new C-130K fleet, the VC
-10's still had a role to service remaining 'out of area' forces, support the NATO role, do the VIP, the rest was deemed surplus and they were expensive to run, including in manpower.
The C-130's would be busy supporting a reinforcement in NATO, both Germany and the flanks.
But most of the heavy equipment, to support and reinforce an armour heavy British Army Of the Rhine, would need to be seaborne.
There was that unexpected war in 1982, which resulted in more tanker and long range jet capacity to support the garrison afterward, in the shape of the ex BA
L1011's, as the US developed it's Mid East focused 'Rapid Deployment Force' in the 1980's, there was some UK role there, exercises in Oman, mainly with paratroops and a few RAF combat jets, after a 15 year break occasionally happened, but this was still within the Cold War context.
The wall came down, Gulf War 1 happened, where the RAF transport fleet coped well enough, but after then the issues of C-130K and VC
-10 replacements, both built in the 1960's, started to emerge.
A European solution for a C-130K replacement was years away, some of the by now very hard worked C-130's needed replacing sooner, both the 1991 Gulf War and the Falklands air-bridge had been particularly stressful on them.
So we got the only solution at the time, the C-130J to replace about half of the fleet. A very welcome boost.
It was known from the start that the C-130J would not meet all the requirements for the UK forces who had gone from the mainly European NATO role, to (or back to) 'Out Of Area'.
Hence the C-17 lease, later buy, then the A400M.
So we have gone almost full circle for the RAF transport aircraft fleet in a 30-40 year period, if anything the demands are harder now than when insurgences were being fought in the mid and far East during the 1960's, since these were near long established and very major bases, like Singapore.
Now it's all a bit more ad-hoc
A small fleet of C-27J's would then make sense, in the SF
support role or just general intra theater work like the US is planning. In both cases the in flight refueling probe would be needed, in the latter case to ease deployment.
But the only way to pay for them might just be if some were tacked on to the US order and a very good deal was struck.