@Noviz - Airships are much harder to shoot down than you'd think
I agree with 'heliumblimp', airships are much harder to shoot down than you'd think.
In WW-I there were many accounts of where German airships over London were shot at and the bullets passed right through them without significant damage. Even filled with highly flammable hydrogen, the airships did not catch fire. The only damage to the ship was to the gas cells (bags) that were specifically hit, these simply lost their gas (hydrogen). As there were many gas cells, the buoyancy lost by bullets passing though a few bags was small; even then--with a cell taking a finite time to deflate--any noticeable loss of buoyancy only occurred after the ship had left the combat zone.
It was not until the British developed incendiary 'bullets' that would specifically catch the hydrogen on fire that airships were very vulnerable.
However, today, any such airship would use helium and not hydrogen, thus both bullets and incendiary shells would have little effect. In fact, the cellular nature of the airship combined with helium and the use of modern materials not available back then, would make the airship quite a formidable device (especially so given that its size and large lifting capacity would also allow it to be extremely well armed both with attack and defensive weaponry).
Unlike a plane, even if hit with a missile and badly damaged, its large size and that it's mostly cellular 'packets' of helium, large parts of it would likely remain buoyant (at least until it could escape the danger zone--as did the German Zeppelins of WW-I).
Combine the airship's intrinsically buoyant properties with an operationally redundant design (i.e.: where multiple copies of operational systems are widely distributed across the airship) and it's likely to still function, even with significant damage.