 Large submarines (for example, Echo and Oscar classes) were developed to carry these weapons and shadow United States battle groups at sea, and large bombers (for example, Backfire, Bear, and Blackjack models) were equipped with the weapons in their air-launched cruise missile (ALCM) configuration.Cruise missiles generally consist of a guidance system, payload, and aircraft propulsion system, housed in an airframe with small wings and empennage for flight control.Payloads usually consist of a conventional warhead or a nuclear warhead.