Land Rover Repair: rear suspension, air suspension system, loud thump

Question
Today, I was driving down the highway in my recently purchased 2001 Disco 2 (120xxx miles).  Suddenly the rear end made a loud thump as it would if it were bottoming out.  After that, the vehicle started bobbing up and down as I went down the road.  I pulled off at the first exit, wondering if I had a flat.  Tires were fine, but the rear end was practically sitting on the tires.  It wasn't really drivable so I had it towed to a nearby independent shop, but I'm not sure if they are familiar with the Land Rover's air suspension system.  Does this sound like a compressor?  I've heard that a leaky bag can also make a compressor go bad from working it too hard.
Also, no dash warning lights came on when this happened.  Both sides sank evenly and suddenly.
There was also a fair amount of snow, slush, and ice on the ground and it was terribly cold (about 1 degree F)


Answer
It sounds like an air bag blew out.  The least expensive fix - and indeed the only fix a general repair shop can do - will be to buy a coil spring conversion kit and get rid of air suspension.  The conversion kit costs less than the parts to repair a blown bag, and it can be fitted by anyone with basic hand tools.  You can buy kits from Atlantic British, 800 533 2210 x 232   Talk to Brad, say you heard of them from me and he can get you squared away.