The part of your post I've highlighted was/is not always the case. And based on the trends I see in naval weapon development, I see the advantage tipping towards the surface platform going forward, so we're likely to see the helo-launched anti-ship cruise missile (ASCM) fall even further out of favour than it already is.
Broadly speaking, naval SAMs can be classified into two categories: Area Air Defence (AAD) and Point Defence. In a classic naval task group concept, at least one ship will be an AAD platform, designed to be able to protect the entire TG against air threats because its missiles are sufficiently long-ranged. A point defence SAM is a short range missile generally designed to only protect the ship they're carried in from air threats.
If we look at common ASCMs, say a Harpoon
, Wikipedia says we're looking at a ~110 NM range for air-launched variants. A common point defence SAM like the Sea Sparrow
has a range of about 10 NM. An AAD SAM like the SM-2
can reach out to about 100NM.
Air-based surface search radars are pretty good, again thanks to the advantage of altitude. This Leonardo
radar claims a surveillance range of 200NM, so theoretically a helo carrying ASCMs could organically target and fire upon a ship in a TG without being able to be counter fired upon.
So why isn't every navy in the world using helo-launched ASCMs to increase their offensive range? My guess is that this is primarily due to weight/range limitations of the helo. Missiles are super heavy, and each time you load one onto an aircraft you're paying a significant range/endurance price. By the time you've loaded two, flown far enough away to get within weapons release range of the enemy (assuming you don't waste gas searching because you don't know exactly where they are), and fire, you probably have to return home almost immediately. You have no guarantee that 1-2 missiles is going to be effective against a modern defensive suite on your target, and now the enemy probably knows exactly where your force is because the helo probably had to fly in a nearly straight line from blue to red based off the fuel limitations.
Extended range missiles seem to be the name of the game moving forward. Russia is developing Zircon
, a hypersonic ASCM which they claim has a range of ~550-1100 NM. China is claiming that new variants of the HQ-9
SAM have a range of over 160 NM. This is going to put the nail in the coffin of the helo as a viable ASCM launch platform IMO (at least in a peer-to-peer conflict, some countries might continue to use them to attack less capable ships or shore targets without GBAD).