April 2,2008: The U.S. B-2 bomber has been unofficially grounded since one of them crashed shortly after taking off from an airbase on the Pacific island of Guam in February. The wreckage is still there, and being intensively investigated. The B-2 has not been officially grounded because it's uncertain what caused the crash. Without that knowledge, there's nothing to fix on the remaining 20 bombers.

The most expensive aircraft ever, each of the 21 B-2s costs over $2 billion in development and construction costs. The 170 ton bomber can carry 22 tons of bombs. There's not a big need for the B-2 at the moment, as the older B-1s and B-52s can deliver bombs cheaper, and just as reliably. Smart bombs have greatly reduced the need for heavy bombers, since one smart bomb can do the job of over a hundred "dumb" bombs. The greater accuracy and reliability of GPS guided JDAM smart bombs means that smaller bombs are now preferred. Thus a heavy bomber can carry over two hundred 250 pound SDB smart bombs. Thus equipped, it's not unusual to only need one heavy bomber over Iraq, or Afghanistan, taking care of all requests from combat troops below.

The B-2 is stealthy, and this would be a major asset in a war against a nation with a decent air defense systems (radars and missiles.) Thus the air force is taking its time to discover what went wrong with the B-2 on Guam (where four of the bombers were stationed), so that changes can be made to the other B-2s.