B52s are used to carry nuclear bombs. I've seen them at March Air Force Base taking off and landing. A group will take off before the others land, ensuring a fleet is always airborne with nuclear bombs. It's been that way for a very long time and I have a feeling it's status quo at more than 1 base. I don't think they fly out of Edwards with nuclear bombs, but we never know. If the plane was going down and had nuclear bombs, the pilot may have initiated a self destruction mode. The rank of the pilot can indicate what may have been on the plane.