Over Iraq, as over Afghanistan, the heavy bombers dropped most of the bombs, by weight. The B-2 was fine, the few times it was used. But the massive amount of maintenance required on the B-2s radar absorbent skin restricted the number of times the B-2 flew. Most of the heavy lifting was performed by B-1s and B-52s. While the B-1 is twice as expensive to operate, per flight hour, there were adequate ground crews and spare parts to keep "The Bone" (as the B-1s are nicknamed) in the air. The B-52 was old reliable. Literally. The B-1s carried full loads of JDAMs. The B-52s would often carry dumb bombs and cluster bombs internally and JDAMs hung under the wings. Two of the B-52s were equipped with Litening Targeting pods, which had sensors for spotting targets and lasers for pinpointing them for laser guided bombs. This made the B-52s very effective bombing machines. Aerial refueling would keep B-52s and B-1s in the air for hours, providing ground troops with firepower when they needed it. There were 14 B-52s flying out of a base in Britain, contributing over a hundred sorties. These aircraft are on their way back to the United States. Other B-52s also operate out of the Indian Ocean island of Diego Garcia, where they also provide support in Afghanistan.