The Chinese have developed and apparently also introduced into service a heavylift transport aircraft of approx. the same class as Il-76 and C-17, the Y-20.
|I simply assume you know which is which, period.|
This is a nice excuse to look into a peculiarity of transports: They may be used for attack, too.
|iconic Ju 52/3m (kind of German DC-3/C-47) used as an auxiliary bomber|
A Chinese H-6K, a dedicated heavy bomber from the early Cold War, can lift and launch six at least superficially impressive long-ranged supersonic anti-ship missiles YJ-20. To maintain this capability may require about 100 flying hours of a dedicated aircraft with a dedicated crew, good for little else (though a bit of "carpet" bombing and naval scouting with a crude but powerful long range radar is possible as well).
Now imagine a transport aircraft could be used for the same purpose. The crew could serve as transport crew in peacetime, and so could the plane. The entire naval attack training could be limited to simulator hours.
How is this possible? With a different kind of missile launch, launch by pallet. It requires no modification of the aircraft itself at all.
This approach was discussed many times, but naturally there's the bomber lobby's self-interest working against it.
Let's have a look at the YJ-12 missile, since its employment by Y-20 would compare well to the H-6s:
YJ-12 length: approx. 6.2 m
YJ-12 span: less than 1 m
YJ-12 mass: approx. 2.5 metric tons
The cargo bay of the Y-20 don't seem to have been published yet, but they're likely very similar or superior to the C-17's even though the two aircraft are unlikely to compete for orders, ever.
C-17 cargo bay length: 26.82 m
C-17 cargo bay width: 5.49 m
The cargo capacity of the Y-20 is said to be 60 or 66 metric tons (depending on publication), let's use 35 metric tons as assumption. The Y-20 is likely able to carry 35 metric tons on an entire sortie in cooperation with Su-27-based Chinese fighters, even if operating from farther inland airports or airbases.
Let's also assume that the complete rig consisting of YJ-12 missile, pallet and braking chute weighs about 3.5 tons. Weight-wide 10 of these rigs would fit in.
Width-wise it should easily be possible to store two YJ-12 side by side on different pallets, but storage side-by-side depends more on the cargo bay floor design anyway.
Length-wise I assume a complete rig length of 7 metres. This would allow for 3 missiles behind each other, but it might be possible to fit 4 behind each other as well.
Thus it should be possible to launch six YJ-12 anti-ship cruise missiles from a Y-20 transport aircraft without any daring concepts like vertical stacking, more than one missile per missile rig or more than two missile rigs side-by-side. That's the exact same capacity of a dedicated bomber, the H-6. Smaller and particularly shorter missiles would allow for more missiles carried. It might be possible to fit 20-30 missiles similar to Club-A (200+ km range) into a Y-20 transport-bomber with some rather daring storage methods.
The training required would mostly be simulator training for the cockpit crew and some training for loadmasters, in order to avoid failures of the rigging.
There are hardly any Y-20 in service so far, but dozens of other transport aircraft are in service. The addition of the concept of transport-bombers to the dedicated bombers and strike fighters would allow the PR China a saturation attack of hundreds (300+, maybe 400+) of anti-ship missiles from ~ 400 km distance to a naval battlegroup. This protects well against the battlegroup's surface-to-air missiles. Few dozen escort fighters (Su-20/-35) would suffice to all but eliminate the threat from carrier-borne fighters since it's impossible to get all of them into the air (or have them on station beforehand) and fighters usually carry few (F/A-18: typically 4 or 6, theoretical limit 12) air combat missiles.
An increase of Y-20 production to a quantity that would justify the development expenses (~100) would enable a saturation attack (~600 missiles of 300+ km range) by transport-bombers alone that no battlefleet would be confident against. The munitions cost of such a saturation attack would be less than half of a single USN destroyer's purchase price including its own munitions and maybe a third of the purchase costs of the missiles that would be expended in an attempt to defeat the attack.
I'm fairly confident that the Chinese are more keen to copy the Soviet anti-ship bomber approach of the 70's and 80's*, which used dedicated long-range bombers. They rarely seem to innovate (an exception being the anti-ship ballistic missiles which were invented but not introduced by the Soviets in the 70's), and the usual forces of bureaucratic self interest (of in this case a dedicated bomber force and the force of two-engine multirole combat aircraft) are no doubt in play against the transport-bomber concept as well.
The transport-bomber concept still adds to what one should think of the large Russian transport aircraft fleet and a likely expansion of the Chinese one.
*: background info