I imagine this as an upgrade program in the early 90s. Which would be interesting to see if the AA capabilities of the US Army ground forces were increased.
Debatable, because the USAF would
hate to give the Army any AA capabilities at all.
I'm assuming Sidewinders would be barely acceptable, since those have a known air-to-ground mode. Though IIRC Sidewinder capability really comes from
Sidearm capability, and those are "I
know that Zeus did
not just light my ride up with a radar... (BOOM!!!)" tools. I imagine that any helo pilot with Sidearms would be positively
twitchy on their trigger, soon as the RWR chirps and the Sidearm growls, trigger is pulled.
I suspect that any development for carrying Sparrows or AMRAAMs would come from the Navy and/or Marines, not the Army. Which would mean that the Army would get the capability only to preserve common avionics between everyone.
That's also interesting, because any successor to the AH-56 should appear in sometime between 2010 and 2015. It would depend a lot on how it would turn out and whether it would find the same number of buyers as the AH-64.
I suspect that
the replacement for the Cheyenne would end up as a tiltrotor. Equal or greater speed, greater
tactical range. Something that could escort the Osprey (and the Marines would cheer loudly to have that).
As to number of buyers, well, the US buying thousands of AH56s in the 1970s would mean that thousands of low-hour AH1s would be available. So I think there would be
lots more countries, that had bought surplus AH1s in the 1970s, that would be interested in buying the new hotness. Or that would at least be interested in buying high-time but freshly overhauled AH56s. Didn't the UK go straight for buying AH64Ds, skipping the earlier versions? Same idea (yes, I know the UK bought brand new).