Hi cfschris,
Apparently AVSIM's site has been hacked and they've lost most of their site including their File Library (and it sounds very severe)!
There is an alternative HUD posted here on the FSDT board. It isn't several variations like the AVSIM one, but hope it helps:
http://www.fsdreamteam.com/forum/index.php?topic=416.0Here is a press release from AVSIM that I found over on the ukmil.org.uk site:
PRESS RELEASE: AVSIM Hacked!!
Tom Allensworth, CEO and Publisher of AVSIM, today issued the following announcement; “We regret to inform the flight simulation community that on Tuesday, May 12, AVSIM was hacked and effectively destroyed. The method of the hack makes recovery difficult, if not impossible, to recover from. Both servers, that is the library / email and web site / forum servers were attacked. AVSIM is totally offline at this time and we expect to be so for some time to come. We are not able to predict when we will be back online, if we can come back at all. We will post more news as we are able to in the coming days and weeks.