I think you need to read my post again - when trying to bring one of these down you would aim at the engines and cupola,
not the envelope and main structure. Knocking out an engine on a HAV that relies on 30-40% lift from its shape is a serious design flaw for survivability - take out the engine or its fuel supply or controls and the HAV will go down.
As for proximity detonation of surface or air to air weapons, then there are many weapons out there that would not 'pass right through' the HAV. If you look at something like ASRAAM (
Matra-BAe AIM-132 ASRAAM ASRAAM - The RAAF's New WVR AAM) that has many transputers on board, it could be programmed to to recognise the shape of a HAV and then aim at the vulnerable points - plus even if the impact fue failed the EMI laser proximity fuse would do its job. ASRAAM is not the only missile with this type of technology.
A FROGFOOT, FULCRUM, FLANKER, Mirage or other FJ with gun(s)/missiles would make mincemeat of a HAV. As would a fighting warship.
Finally, what is the point of an AEW and Comms capability if you can't think of using it in a contested environment?
The E-3 AWACS, in the same role as is being proposed by some on here, relies upon speed and an ability to run away from any adversary at least at one third the speed that the advervesary bears down on them. So a FULCRUM approaching at 16miles a minute can have its progress cut down to 8 miles a minute by the E-3. At the range that the E-3 would detect/recognise the adversary FULCRUM that buys it a good 20 minutes for friendly fighters to be vectored in (plus it can descend and hide behind terrain/clouds quickly). 20 minutes is a lot of fuel to a fast jet and so the difference between an E-3 retrograding at 8 miles a minute and a HAV at 1.5 miles a minute is HUGE when it comes to survivability.
Sorry, but using a HAV for AEW and C2 is absolutely crazy!!! Indeed, buying it for anything military related seems dumb: as strategic airlift the C17 can carry more (at least 5 times as much) and get it there faster (at least 7 times as fast which is key to strat airlift), for tactical airlift the Chinook is quicker and likely to be far more survivable, for ISTAR/C2 then I have already made my points and I can't think of any other use that the HAV could realistically find a niche. Flying for 3-4 days is also a fallacy, 3 platforms fkying 'Relief in Place' provides far greater flexibility when it comes to servicibility and ability to switch the capability's effect in various areas of the battelspace.
Sorry, I want to believe this is a great idea but I have come to the same conclusions as the post made by John Wood (former Airship Industries) in 2009.
The B Word