Need book title help.
 

I'm trying to remember the title of this fiction novel I once read. It was about some people on an airplane and while they are in the air, nuclear war breaks out all over the world; so they head to Azores and then to Antarctica in order to be safe from the radiation cloud. Anybody read this book and know what it's called?

is it Down To A Sunless Sea, by David Graham ?

That's the one, Thx smokedragon!