During the past decade’s operations in Afghanistan and Iraq, the U.S. military has come to rely heavily on the continuous presence overhead of both manned and unmanned aircraft. Unmanned aircraft are particularly attractive for such missions because they can be designed to remain in the air beyond the physical endurance of human air crews and because they do not put people at risk during operations in potentially hostile airspace.
Airships—also known as lighter-than-air vehicles—have been proposed as alternatives to some of the aircraft (such as the Predator) that the Department of Defense (DoD) currently uses for those missions. At the request of the Chairman of the Senate Armed Services Committee, CBO examined DoD’s plans and proposals for airships in a collection of exhibits with descriptive text shown below.Recent Development Efforts for Military Airships
Unmanned airships—such as those depicted in Exhibit 1—have the potential to remain in the air many times longer than would be practical for conventional aircraft. Consequently, the military services are exploring a variety of designs for unmanned airships capable of carrying ISR (intelligence, surveillance, and reconnaissance) sensors (see Exhibit 3). The technology needed to field airships for ISR could also be applied to airships meant for airlift (that is, the transportation of people, equipment, or other cargo). Whether airships designed to carry cargo would be manned or unmanned would depend on the specific missions they would perform.
CBO examined the potential capabilities of airships for ISR and airlift missions, and found that:
Because the development of the technology needed for modern military airships is at an early stage, in most cases cost estimates would be highly speculative; therefore, CBO did not examine the costs of airships. Although CBO compared the capabilities of airships with those of other aircraft, assessing their cost effectiveness would require analyzing costs as the relevant technologies are developed.
As shown in Exhibits 4 through 9, CBO examined two types of airships—high-altitude and low-altitude models—when providing comparisons with conventional unmanned aircraft systems for ISR. The Air Force and the Army have already entered into contracts to purchase low-altitude ISR airships for eventual use in Afghanistan. High-altitude models are in earlier stages of development. CBO found that:
As discussed in Exhibits 10 through 13, although most current interest in airships is in ISR platforms, airships could also be developed to move equipment, supplies, or people within or between combat theaters. Airships would have several advantages over other means of transportation. In particular:
Airships used for airlift would still have the disadvantages discussed above for ISR missions, such as greater sensitivity to weather conditions and vulnerability to hostile fire if required to fly over unsecured territory. Whether or not airships would be worthwhile additions to the military’s mobility forces will depend on the progress of their technological development, their acquisition and operation costs relative to those of conventional aircraft, and the utility of their unique combination of payload, speed, and basing flexibility.
Alec Johnson, formerly of CBO’s National Security Division, prepared the analysis, with assistance from David Arthur.