After the death of the US Navy's Airship programs in the early 1960s, the USN has at various times attempted to bring back this capability. One such attempt was the YEZ-2A Program. Following a series feasibility studies, in 1985 the USN decided to issue a proposal for a new AEW airship to provide early warning of low flying bombers and sea skimming missile attacks on task groups. There were three contenders for the program, Goodyear offering a modernized derivative of the ZPG3-W, a Boeing – Wren Skyships for which little details are available, and Westinghouse-Airship Internationals Sentinel 5000. In 1987 the WAI proposal was selected for further development in the form of the subscale Sentinel 1000. Should the demonstrator prove successful a projected 40-50 Sentinel 5000 airships were expected to be ordered. A civilian variant, the Skyship 5000 was also planned. Funding was cut dramatically in 1989 however funds were provided to complete construction of the Sentinel 1000. The Sentinel 1000 first flew in 1991 and test flights began. Testing continued until 1995 when the prototype was destroyed in a hangar fire.
The Sentinel 5000 was to have been the largest class of non-rigid airships to be built at the time. The intended endurance was for 2-3 days, extended to 30 through refueling/replenishment. The crew were to be housed in a 3 deck gondola. The lowest deck was the flight deck above which was the operations deck where the consoles for the AEW radar would be located. The topmost deck of the gondola was to be dedicated to the crew facilities which would have been substantial. Double cabins for the crew, showers, a full galley and even a small gym. Capping the gondola, within the envelope of the airship was to have been the AEW radar. Other features included internally mounted engines for reduced IR signature, ECM countermeasures composite material construction and a fly-by-light control system.