Keith,
but those components in the (earth reference) lateral and vertical planes amount to 2 g acceleration perpendicular to the planform of the plane. No drinks will be spilled unless a passenger has had too many drinks before to be able to cope with his/her glass suddenly becoming twice as heavy.
A g meter inside the plane WILL show 2g and the passengers WILL feel 2 g pulling them straight down into their seats rather than being pushed into the armrests.
In reference to another thread, in the cabin's reference system pendulums will hang straight down, tied down helium balloons will rise straight up and any flying birds will fall straight down accelerating at 1g with a very surprised look on their faces unless they figure out to flap twice as hard - especially those carrying coconuts whether they be african or european.
If you ARE in fact saying the same thing then I am afraid that I was able to misunderstand your post thoroughly.
Cheers,
/ft