use semi-recessed bomb bays. Weapons Large-sized bombs, which may be nuclear, are dropped from hook-type releases or bomb cradles. When a bomber carries many smaller bombs (e.g. iron bombs, JDAMs), the bombs are typically loaded onto mechano-electrical devices known as ejector racks, which allow for larger bomb loads to be dropped with greater accuracy. Guided missiles (frequently standoff missiles) are often carried in the bomb bays of modern aircraft; the missiles are dropped from the aircraft and then accelerate into autonomous flight while the bomber aircraft "stands off" at a safe distance from the target. There are multiple different bomb bay configurations, which can include: Conventional bomb rack The more traditional, fixed bomb rack, a conventional bomb rack like that of the B-52 would have mounted stores in vertical columns making individual store selection and release impossible without releasing all stores ahead in the column line. The advantage of a conventional bomb rack is a prompt release of all stores in short order. Bombers like the B-52, the B-1 or the B-2 use custom designed bomb rack support structures with their own designation e.g. Common Bomb Rack (CBR), Common Bomb Module (CBM), or Smart Bomb Rack Assembly (SBRA). These bomb racks may have special store release control mechanisms. Aside from the release options of a rack a pilot can select release mode for releasing one or multiple stores. Stores can be jettisoned selectively in single mode or ripple mode or salvo mode. The term ripple applies to the single- or ripple and single- continuous release mode from one or from mirror stations. Salvo release mode applies to a combination of several stations together e.g. adjacent stations. For multiple store release an interval timer can be set to release stores in fixed time steps. For an external store emergency release there may be a panic button to release all of the weapons. Rotary launcher A rotary launcher is a rotating suspension equipment mounted inside the bomb bay. Rotary launchers have stations of their own and offer the ability to select certain stores within the bomb bay for release. Advantages include the selection ability for different weapons and easier loading for the ground crew. The disadvantage of a rotary launcher is a slow release of stores. The rotary launcher of the B-1 for example requires seven seconds until the next store is rotated into release position. An example of the concept is