Donald McKelvy
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14 August 2009
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Airship Industries (UK) Ltd teamed up with Westinghouse Electric Corporation to develop the civilian SkyShip 5000 and the United States Navy YEZ-2A Sentinel 5000 Airborne Early Warning (AEW) airship in the mid-1980s. In 1990, Airship Industries collapsed and the company became Westinghouse Airships Inc. (WAI). In 1996, WAI and other assets were sold to a company that became Advanced Technology Group (ATG) and then World SkyCat.

Concept art for the civilian SkyShip 5000 airship.


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The Naval Airship Program (NAP) was initiated by Naval Air Systems Command in 1985 to investigate the suitability of airships in the Airborne Early Warning (AEW) role. Airship Industries and Westinghouse Electric beat Goodyear Aerospace for a $168.9 million in June 1987 for an operational development model (ODM) airship. The United States Navy designated the Sentinel 5000 as the YEZ-2A.

In October 1988, NAP evolved from an exclusively US Navy program to one by Defense Advanced Research Projects Agency (DARPA); in FY90 became funded under DoD's Air Defense Initiative. Program focused primarily on demonstration of long-range, long-endurance surveillance system capable of detecting low-observable sea-skimming cruise missiles; other potential applications included OTH (over-the-horizon) targeting, drug surveillance and interdiction functions. Original USN requirement was for independent airborne early warning system capable of operating with surface attack groups anywhere in the world. ODM vehicle planned to have unrefueled endurance of two to three days; by refueling and replenishing from surface units within a task force, a mission capability of some 30 days was intended. Designated USN missions were surveillance and targeting, AEW, and communications.

The Sentinel 5000 was to be the largest non-rigid airship ever constructed and would carry a crew of 10 to 15 in a wide-bodied and pressurized gondola. The upper deck would provide living accommodations for the crew, including double cabins, showers, separate ward room galley and a small gymnasium.

A full-scale ground test vehicle for the gondola and propulsion system was constructed at Naval Air Station (NAS) Weeksville in Weeksville, NC according to Jane's while the The Airship Heritage Trust claims NAS Lakehurst in Lakehurst, NJ.

Statistics from Jane's All the World's Aircraft 1992-93 (1992)

Dimensions External:

Length overall: 129.54 m (425 ft 0 in)
Max diameter: 32.00 m (105 ft 0 in)
Height overall: 46.33 m (152 ft 0 in)

Length overall: 25.91 m (85 ft 0 in)
Max width: 5.08 m (16 ft 8 in)
Max height: 7.32 m (23 ft 0 in)

Dimensions Internal

Envelope volume 70,792 square meters (2,500,000 cu ft)

Estimated Performance:

Max level speed (3 engines) 88 knots (163 km/h; 101 mph)
Operating height: S/L to 3,050 m (10,000 ft)
Pressure ceiling: 4,270 m (14,000 ft)
Max. endurance at 40 knots (74 km/h;46 mhp) at 1,525 m (5,000 ft) more than 60 hours.
Mission capability: 30 days.

Original NASC contract included options for up to five more Sentinels after ODM.

DARPA contract, ending May 1994, included critical design review of ODM. Major redesign of gondola and propulsion system in 1995, aimed at saving some $45 million in development costs. Present status of program is uncertain according to the Jane's web site.


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I can add some information...

The U.S. Navy had been interested in LTA technology since the early 1980s. This led to the Patrol Airship Concept Evaluation (PACE) ca. 1983, and some tests of a Skyship 500. In 1985, NAVAIR commissioned design studies for an AEW airship to work with surface action groups. Boeing, Goodyear, and a Westinghouse/Airship Industries team made proposals. These studies were for vehicles running ~3,000,000 cubic feet.

In 1986, the program was redirected toward an Operational Development Model - basically a proof-of-concept vehicle with an E-2 radar suite. Boeing dropped out, Goodyear bid a ZPG-3W with turboprop engines, WAI bid the Sentinel 5000. WAI won. A mockup of the gondola was built at the Weeksville, NC, hangar.

The USN pulled out in 1988, IIRC. Part of the A-12 eating all of Naval Aviation. But DARPA was interested in the airframe as a carrier for low-frequncy radars and pressed on with the program as funding permitted. Development went slowly, and the fire in the Weeksville hangar in 1994 (IIRC) pretty well killed the program off.

The performance numbers are off...the endurance was 60 hours, not 60 days. But it was planned to refuel at sea, making a 30-day patrol practical.

The politics of the program were very interesting. Within the Navy, the problem was that the YEZ-2 did not have a pointy nose or fire belching out the back. Not to mention that it was a direct challenge to the E-2, and a possible challenge to the P-3...and in the platform-centered communities of that era, this was politically very dangerous.

On top of that, WAI made some politically tone-deaf moves. Most of the subcontractors were in the UK...useful for the Airship Industries design team, bad for Congressional support. The Goodyear design might have been more successful, despite being technically outclassed, on that point alone.
Cool! I was enthused by the YEZ-2A announcement back in the early 1990s and was sorry not to see the program take shape. Thanks to both of you for shedding some light!
Ummm....that Harrier.

Does that even BELONG in the picture?

If it were an ASW platform a single parasite Harrier might make sense as a pouncer, sort of a`manned, recoverable Ikara or a very fast MATCH. However, this was an AEW platform so...WHAT were they going to use the Harrier for?


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I think the Harrier is there just to give a sense of scale.

Enjoy the Day! Mark
Mark Nankivil said:
I think the Harrier is there just to give a sense of scale.

Enjoy the Day! Mark

Yeah. Still, would be fun to imagine the EZ-2A as a flying mooring platform for the Harrier for refuelling and to save fuel by not having to take off vertically... Like the Akron/Macon and Curtiss F9C Sparrowhawk of olden days...


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Stargazer2006 said:
Mark Nankivil said:
I think the Harrier is there just to give a sense of scale.

Enjoy the Day! Mark

Yeah. Still, would be fun to imagine the EZ-2A as a flying mooring platform for the Harrier for refuelling and to save fuel by not having to take off vertically... Like the Akron/Macon and Curtiss F9C Sparrowhawk of olden days...

But the EX-2A could use a variation of BAe's "Skyhook" system rather than the trapeze system used by the Akron/Macon and later by the GRB-36. This could make for a more effective "flying aircraft carrier".
Yes, but why bother?

Remember, the hole idea was to operate in concert with surface ships. To be a mile-high mast for an advanced radar.

And, ultimately, a missile illuminator for SM2 missiles.

When the Regan Administration reactivated the Iowa-class battleships, strategists realized their newly created battle groups would need Airborne Early Warning radar after a British warship was lost to sea-skimming Exocet missiles. Congress finally funded a new airship program, called by many names and acronyms in its tumultuous life, with the object creating a modern radar picket airship operating without aircraft carriers. This film was made during the short period after funding was received and before an administration change pulled the plug. It is a window into the program’s goals and the technology of the mid-1980s that sought to fill the order. Following the funding cut the program limped along, building a scale prototype, but it too was never given a chance as its WWII timber hangar burned down, destroying it and any hope for a Navy or Coast Guard airship in the 1990s.

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