Hmm...I'm sure I've posted on this recently. The Lynx, and I suspect all the others that have so called "negative" pitch for sticking to ship decks, don't actually have negative, ie below zero degrees, pitch. They can go to sub minimum(sub min) which is a setting below the normal minimum pitch on the ground. With the Lynx, it's about +2 degrees.
The Lynx also uses this sub min setting for certain ground runs.