N.W.S. on a Harrier grip?

Hi,

I have a Harrier GR.3/T.4 grip, one switch has the letters N.W.S. next to it, can someone please tell me what this switch would be used for. (What does N.W.S. meam?).

cheers & thanks in advance,

-John:)

P.S. I’m still looking for an original GR.1/T.2 – GR.3/T.4 Harrier aircrew manual.