Does it mean full Hull Value or current Hull Value? ie: are Y-wings immune? I'm guessing no as afaik Damage doesn't actually reduce your hull value, but I'm not sure.
Edited by LagomorphiaFlechette
Hull value always refers to the printed hull value on the card.
You don't actually ever lose hull points, you are destroyed when the number of damage cards = hull value. But for a lot of us we tend to think of them in terms of HP's because it's almost the same thing, and we're used to thinking that way.
Correct. Your hull value is the yellow number. You are destroyed when the number of damage cards drawn is equal to or exceeds your hull value.
Which means Y wings, Bombers, Firesprays, YT-1300s, and Shuttles are currently immune to the stress effect of the Flechette. Also, a HWK can become immune with a hull upgrade.
Edit: 
'd
Edit:
Every time I see a rules post with 0 replies I figure I'll either be 'd or will someone else.
Edit:
Every time I see a rules post with 0 replies I figure I'll either be
At least we don't run around yelling "FIRST!" at each other.
Edit:
Every time I see a rules post with 0 replies I figure I'll either be
At least we don't run around yelling "FIRST!" at each other.
That is most embarassing when you do that and aren't. This board is even nice enough to let us know when changes are made so you couldn't go back and add it if you are first without getting caught.
I'm glad the OP had the right answer to start with and for the right reason. A ship's "hull" is fixed at the start of the game and only serves to show how many damage cards it takes to destroy it. Now with this Flechette weapon it has another use but the general rules will still apply.
SEVENTH!
But yes, I believe the consensus is correct. Your hull value does not actually change (well, barring Hull Upgrade); you simply accumulate damage equal to or greater than your static hull value, at which point you go boom. So certain ships - and other ships, should they take a hull upgrade - are immune to the stress effect of Flechettes.