Hello:

Re commercial aero. usage:

Saw this on a link:

"Aeronautical SSB Frequencies
Aircraft crossing the Atlantic still use SSB to communicate with the
National Air Traffic Service (NATS) in Shannon, Ireland and..."

I thought that all commercial aero. stuff was always just plain AM.

Can someone please explain when (and if) SSB is used rather than plain AM
for commercial air communications for
air to ground, and vice versa ?

Or, is this a very out of date link, perhaps ?

Thanks,
Bob