Current roles deemed "support" by the Navy include: carrier on-board delivery (COD), electronic surveillance (ES), electronic warfare (EW), and airborne early warning (AEW). Another possible support role for a carrier-based aircraft is that of aerial refueling.
Among combat roles, while anti-submarine warfare (ASW) and anti-surface warfare (ASUW) are sometimes also considered "support"; fighter, bomber, and ground attack roles are not.
Current carrier-based fixed-wing support aircraft used by the US Navy, and which would presumably be replaced by the CSA, include:
Other support aircraft used by the US Navy in the recent past include:
The first would be in economies of scale in manufacturing. With a lower per-unit cost for each support aircraft and its spare sparts, the expense of purchasing the support aircraft (as well as maintaining it over the course of its lifespan) is reduced.
Another cost saving would be in reduced training expenses. Maintenance crewmen would only have to be trained for one support aircraft, rather than many.
Still another would be in reduced logistical requirements. With the same spare part, such as an engine, avionics component, tire, and so on able to be used for aircraft used for multiple roles, either fewer total spare parts could be brought on board, or the same-sized pool of spare parts could be applied to any support aircraft, giving the crew more options.
Furthermore, in a constrained environment such as a budget crunch or emergency battle damage control, cannibalization of some support aircraft to keep others flying and functional is a greater possibility.
For these reasons, the US armed forces as a whole are moving toward vehicles and weapons platforms that are generalists rather than specialists, capable of performing a wide variety of missions, or serving as a base from which variants can be produced to fill specialized roles.
Examples include the replacement of many different aircraft by the F-35 Lightning II; and the production of the Stryker armored vehicle, which serves as a base for a wide array of variants.
It may be noted that the Navy is already some steps toward a CSA, rather than having a completely different and separate aircraft type for each support mission. The C-2 Greyhound is a derivative of the E-2 Hawkeye, and the two aircraft have significant parts commonality. The ES-3 Shadow was a derivative of the S-3 Viking. And the S-3 Viking fills at least three different roles, not just one.
The Navy seems to favor the role of EW to filled by converted attack aircraft. The EA-6B Prowler, based on the A-6 Intruder, is slated to be replaced by the EA-18G Growler, based on the F/A-18E/F Super Hornet. (Also note the U.S. Air Force's EF-111 Raven EW aircraft, based on the F-111 Aardvark fighter-bomber.) Moreover, the Super Hornet is also capable of serving as an aerial refueler for other Super Hornets. While these airframes were not designed in advance for the support role, their use is nonetheless evidence that the US military prefers versatility and multi-capability in its vehicles, and to avoid designing a new platform for each possible role unless it is necessary.
Such trends would seem to point toward adopting the CSA as in line with current policy priorities and needs.