Airship Industries
Encyclopedia
Airship Industries was a British manufacturer of modern non-rigid airship
s (blimps) active under that name from 1980 to 1990 and controlled for part of that time by Alan Bond
. A predecessor company, Aerospace Developments, had been founded in 1971, and a successor, Hybrid Air Vehicles, remains active . In addition to its activities in non-rigid airships, the firm briefly proposed, but did not build, a number of rigid
designs; a large non-rigid for the United States Navy
was also unrealised. The historic airship facilities at Cardington, Bedfordshire
(the former Royal Airship Works), were used as a base for the firm's test flying and an assembly site for some of its airships.
—rigid airship for Shell
International Gas.
The Shell project had evidently been in progress since well before AD's formation; in 1975, Munk stated that the idea had emerged "about seven years ago." Shell planned to use the airship to transport natural gas in gaseous form, eliminating the costly equipment associated with shipping liquefied natural gas
by sea and, in particular, the need for large amounts of fixed plant in politically unstable countries. Barnes Wallis
had been involved in the airship project in its early stages but withdrew due to problems with his design for a very large non-rigid.
The natural gas would have functioned as the primary lifting gas
on the loaded voyage, with a small amount of helium, plus hot air from the airship's (gas-fuelled) engines, supporting it on the empty return leg. The ship's structure would have been "of a semi-monocoque type of stressed metal/skin honeycomb sandwich
construction."
The project was "terminated before a detailed study of the concept could be crystallised." AD's work "showed that the concept was impracticable" but "[brought] Aerospace Developments into contact with the latest materials and ideas."
symposium in 1975, dealing primarily with the Shell project, also makes reference to AD's "pursuing the development potential for relatively small non-rigid, advanced technology airships in the half to ten ton payload range for general freight, surveying and airborne jeep applications." These airships were to embody many of the innovative features eventually seen in the AD500 and Skyship 500/600, including vectored thrust and the use of modern materials such as Kevlar. Negotiations were stated to be in process with the governments of Peru
, Ecuador and Nigeria
concerning sales of such airships.
In a May 1976 Flight International
article, Multi-Modal Transport Analysis, an associate of AD (the two firms shared offices in London, with "perhaps a dozen people working full-time" on the project), said contracts had been signed with Venezuela
n company Aerovision for the construction and delivery in 1977 of an initial airship, with a further 21 (which would be "of similar design to the first ship, but...vary in payload and therefore size") to be delivered over the following 10 years. The first airships would be assembled and tested in Britain, with production being "transferred gradually to Venezuela." A family of five airship types was proposed:
The first airship (later to be designated the AD500) was to be of Type B. It would be used experimentally to supply isolated communities in Venezuela's interior and for night-time advertising flights to recoup the ship's cost.
requirements for airships, something that took six months) but also by factors including a change of envelope supplier and revision of the engine and propeller design. The AD500, as it was by then known, first flew from Cardington on 3 February 1979.
The AD500 was "a new-generation airship making use of advanced materials and technology." It was 164 feet (50 m) long and contained 181200 ft3 of helium. Materials used in the ship included thin single-ply polyester
, coated with titanium dioxide
-polyurethane
, for the envelope; Kevlar
for the cables suspending the gondola from the top of the envelope; a Kevlar nosecone moulded in the same manner as glass-reinforced plastic
; and a gondola moulded by Vickers–Slingsby
from Kevlar-reinforced plastic. Other innovations featured in the AD500 included simplified controls and thrust vectoring
— an old airship idea revived — via inboard-mounted Porsche
engines driving vectoring ducted fan
s.
Unfortunately, on 8 March 1979, the month-old AD500 was seriously damaged when the nosecone failed while the ship was moored in high winds. Aerovision subsequently withdrew its financial support, and AD was liquidated
on 8 June.
Five more 500s were subsequently built — one at Cardington, two in Toronto, one in Tokyo, and one in the United States. The ships were mainly used in advertising and filming. However, other notable uses of the craft included sightseeing flights over London, a trial shuttle service between Paris's Orly and Charles de Gaulle airports, and trials with NASA
and the United States Air Force
, United States Navy and United States Coast Guard
. Four 500s were later upgraded to 500HL standards by replacing the 500 envelope with a 600 one to increase lift for heavy payloads or hot and high
applications. Additionally, two more 500 gondolas were commenced but never completed.
, with four Pratt & Whitney Canada PT6
engines. It would have been capable of carrying payloads of up to 58 tonnes (57.1 LT).
Redcoat Air Cargo
proposed acquiring four R40s by 1984 and "opt[ing] out permanently from conventional aircraft."
A second design, the R150, followed. The R150 was to have been 174 metres (570.9 ft) long, with 152000 cubic metre of gas and a payload of 75 tonnes (73.8 LT), and propelled by four Garrett AiResearch
turboprops, with an additional Allison
turboshaft providing air to nose- and tail-mounted thrusters for purposes of low-speed control. The use of natural gas, or a combination of natural gas and LPG, as fuel was considered. Unlike the R40/R130, which was to have had a traditional rigid structure, the R150 was intended to be a metal-clad airship
, with a thin metal shell stabilised by an internal pressure of around 2 kilopascal (0.290075475467502 psi).
Federal Express (FedEx) was reportedly "negotiating the possible purchase of a non-rigid training airship" in early 1981, with the possibility of an order for "75-tonne payload R.150 cargo airships" to follow, and Redcoat—through which FedEx had approached AI—switched its order to the R150, ordering four airships with options
on another 10. FedEx was motivated by fuel-efficiency concerns and considered airships suitable for lower-priority 48-hour package deliveries.
However, FedEx stated in late 1981 that its airship plans had been "put aside for the time being" and Redcoat went into voluntary liquidation in mid-1982.
The R150 design was inherited by Wren Skyships when AI's rigid division was split off (see below), and Wren went on to propose new metal-clads of varying sizes.
on the Isle of Man
. The firm continued metal-clad development and began work on a non-rigid design, the Advanced Non-Rigid (ANR). Wren Skyships became the Advanced Airship Corporation (AAC) in 1988. Construction of the prototype ANR was commenced, but envelope problems delayed its completion, and AAC went into liquidation during the early 1990s recession.
Airship Industries followed the Skyship 500 with the similar but larger Skyship 600, 59 metres (193.6 ft) long with 6666 cubic metre of helium and seating for up to 18 passengers and two crew. The first Skyship 600 flew from Cardington on 6 March 1984. In all, ten Skyship 600s were built: two at Cardington; three at Weeksville, near Elizabeth City, North Carolina
; one at Sydney; two in Japan; and one at Lakehurst, New Jersey
. As was the case with the 500, two additional gondolas were commenced but never completed.
Like the 500, the 600 was employed in the traditional blimp role as an advertising and camera platform and tested in a variety of other civil and military roles. The sightseeing operations begun with the 500 were expanded to take in a number of additional cities worldwide, including Paris, Toronto, Montreal
, Sydney, Brisbane
, Melbourne, San Francisco and Zurich
, as well as London.
in 1983 was followed by a second for £7 million, this time underwritten by Alan Bond
's Bond Corporation, the following year. The firm had posted a £2.3 million loss for the six months to 30 September 1983, as a result of delays in the 500's testing and certification, difficulties in setting up a Canadian subsidiary and revenue lost due to the certification delays. It had lost almost £10 million between June 1978 and September 1983, and its share price fell from a 1983 high of 147p to 56p in March 1984. However, AI reported its first profit, some £50,000, in the 15 months to 30 June 1985.
for a radar-carrying Battle Surveillance Airship System (BSAS). AI responded with the Skyship 5000, "a concept airship of about 70000 cubic metre" The BSAS programme was subsequently renamed the Naval Airship Surveillance Program (NASP), then the Organic Long Endurance Airborne Area Surveillance Airship System, and finally became the Naval Airship Program. In mid-1985, the Naval Air Development Center awarded three six-month contracts for further studies to, respectively, Goodyear Aerospace, Boeing
paired with Wren Skyships, and Westinghouse paired with AI. The Navy was reported to be "interested in up to 75 airships." On 5 June 1987, Westinghouse–Airship Industries (WAI) won the contract to build an Operational Development Model (ODM), or prototype, with the possibility of a production run of 40–50 airships if the ODM proved successful in trials. However, NASP was cut from the fiscal year 1989 defence budget. Congress later authorised funding to continue the ODM's development, and the Defense Advanced Research Projects Agency
inherited the programme from the Navy.
In the design proposed in 1989, the Sentinel 5000, designated the YEZ-2A by the Navy, would have been 143 metres (469.2 ft) long and 32 metres (105 ft) in diameter, containing 70864 cubic metre of helium. A crew of 10–15 would have been accommodated in a triple-decked, partly pressurised gondola, on top of which (within the envelope) the radar antenna was to be mounted. The ship would have been powered by two CRM diesel engines, with a supplementary General Electric T700 turboprop for "dash" situations. It would have offered an unrefuelled endurance of two to three days, which could be extended to 30 days through refuelling and replenishment from surface ships.
AI produced a smaller airship, the Sentinel 1000, as part of the development programme. The 1000 was a half-linear-scale model of the 5000, having a modified Skyship 600 gondola but a larger (10000 cubic metre) envelope and an empennage
resembling the "X" form planned for the 5000, rather than the cruciform one of the 600. Other features included fly-by-light controls, an envelope material that eliminated the need for routine hangaring and a ground-handling technique that required a comparatively small crew of eight. However, the ship, which was assembled at WAI's Weeksville facility in North Carolina, did not fly until 26 June 1991, by which time AI had collapsed and Westinghouse had taken full control of the programme.
From an early stage of the programme, AI contemplated a civil version of the 5000, variously reported as accommodating between 140 and 300 passengers, for applications including both luxury shuttle services and conventional scheduled flights. However, this project was dependent on the success of the military programme.
efforts failed, the firm sought to improve its financial position through a sale and leaseback of the Cardington facilities, an attempted sale of its U.S. operations to Lou Pearlman
's Airship International, and efforts to renegotiate the YEZ-2A contract from fixed price
to cost plus
. However, trading in AI's Isle of Man–based holding company was suspended in August 1990, and administrative receivers were appointed in September.
Slingsby acquired the marketing and intellectual property rights to the civil versions of the 500, 500HL and 600—except in North America, where Airship International was the appointed agent—as well as work in progress, plant and fixed assets and UK, U.S., and Japanese type certificate
s. Westinghouse acquired the corresponding rights to military variants of the three designs and took full control of the YEZ-2A programme. Airship International acquired the share capital of AI's U.S. operation, one complete and one incomplete 600, an incomplete 500HL and support equipment. The rights held by Airship International subsequently passed to Airship Management Services
.
Aside from the Sentinel 1000's role as a demonstrator for the 5000, Westinghouse promoted the 1000 itself for roles such as demonstrating over-the-horizon targeting
and acting as a sensor platform for drug interdiction. The UK's Ministry of Defence
reportedly sent pilots to the U.S. in early 1992 to evaluate the airship. In late 1993, the Sentinel 1000 became the first aircraft with fly-by-light controls to receive FAA
certification and possibly the first such aircraft to be certificated anywhere.
In 1993, Westinghouse was "still hopeful" that a prototype YEZ-2A would fly in 1998. The roles envisaged at this stage were "radar surveillance in support of U.S. Navy fleet operations and theatre missile-defence for the U.S. Army." The prototype would have been constructed at Moffett Field, California.
On 2 August 1995, a fire, apparently started accidentally during welding work, destroyed the Weeksville hangar and its contents, including the sole Sentinel 1000 and the mock-up of the 5000's gondola. Despite the setback, work on the 5000 project continued, and the firm projected an airship somewhat larger than the 1000, the Sentinel 1240, which would have been capable of accommodating 40 passengers. Changes to the 5000's design were also proposed, including a simpler, single-deck, gondola and the replacement of the two gondola-mounted diesel engines and one turboprop with three Zoche diesels, two mounted on a beam spanning across the envelope and one at the tail. Both Moffett Field and Lakehurst were under consideration as construction locations. However, further plans were stymied by the sale of Westinghouse's defence-electronics business to Northrop Grumman
in early 1996. Westinghouse Airships did not form part of this deal; its designs, patents, and other assets were subsequently acquired by British investor group London Wall, in a deal led by Roger Munk.
, the SkyCat
.
After ATG went into administration, its assets were acquired in 2006 by an Italian–British consortium and the new business named SkyCat Group. However, SkyCat Group itself went into administration about a year later, and its assets were acquired by a new firm, Hybrid Air Vehicles (HAV), set up by British investors. , HAV continues to develop the SkyCat. HAV and partner Northrop Grumman won a $517 million LEMV contract to build 3 HAV 304's for the US Army in Afghanistan. The first one will fly later this year and will be the biggest aircraft in the world.
Non-rigid airship
A blimp, or non-rigid airship, is a floating airship without an internal supporting framework or keel. A non-rigid airship differs from a semi-rigid airship and a rigid airship in that it does not have any rigid structure, neither a complete framework nor a partial keel, to help the airbag...
s (blimps) active under that name from 1980 to 1990 and controlled for part of that time by Alan Bond
Alan Bond (businessman)
Alan Bond is an Australian businessman noted for his criminal convictions and high-profile business dealings, including what was at the time the biggest corporate collapse in Australian history. Bond was born in the Hammersmith district of London, England, and emigrated to Australia with his...
. A predecessor company, Aerospace Developments, had been founded in 1971, and a successor, Hybrid Air Vehicles, remains active . In addition to its activities in non-rigid airships, the firm briefly proposed, but did not build, a number of rigid
Rigid airship
A rigid airship is a type of airship in which the envelope retained its shape by the use of an internal structural framework rather than by being forced into shape by the pressure of the lifting gas within the envelope as used in blimps and semi-rigid airships.Rigid airships were produced and...
designs; a large non-rigid for the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
was also unrealised. The historic airship facilities at Cardington, Bedfordshire
Cardington, Bedfordshire
Cardington is a village and civil parish in the Borough of Bedford in Bedfordshire, EnglandPart of the ancient hundred of Wixamtree, the settlement is best known in connection with the Cardington airship works founded by Short Brothers during World War I, which later became an RAF training station...
(the former Royal Airship Works), were used as a base for the firm's test flying and an assembly site for some of its airships.
Beginnings and the Shell International Gas project
Aerospace Developments (AD) was founded in 1971 by John Wood and Roger Munk. Its first major project appears to have been the design of a very large—549 metres (1,801.2 ft) long with 2750000 cubic metres (97,115,332.1 cu ft) of gas capacity, compared to 245 metres (803.8 ft) and 200000 cubic metres (7,062,933.2 cu ft), respectively, for the HindenburgLZ 129 Hindenburg
LZ 129 Hindenburg was a large German commercial passenger-carrying rigid airship, the lead ship of the Hindenburg class, the longest class of flying machine and the largest airship by envelope volume...
—rigid airship for Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...
International Gas.
The Shell project had evidently been in progress since well before AD's formation; in 1975, Munk stated that the idea had emerged "about seven years ago." Shell planned to use the airship to transport natural gas in gaseous form, eliminating the costly equipment associated with shipping liquefied natural gas
Liquefied natural gas
Liquefied natural gas or LNG is natural gas that has been converted temporarily to liquid form for ease of storage or transport....
by sea and, in particular, the need for large amounts of fixed plant in politically unstable countries. Barnes Wallis
Barnes Wallis
Sir Barnes Neville Wallis, CBE FRS, RDI, FRAeS , was an English scientist, engineer and inventor. He is best known for inventing the bouncing bomb used by the RAF in Operation Chastise to attack the dams of the Ruhr Valley during World War II...
had been involved in the airship project in its early stages but withdrew due to problems with his design for a very large non-rigid.
The natural gas would have functioned as the primary lifting gas
Lifting gas
Because of the Archimedes' principle, a lifting gas is required for aerostats to create buoyancy. Its density is lower than that of air . Only certain lighter than air gases are suitable as lifting gases.- Hot Air :...
on the loaded voyage, with a small amount of helium, plus hot air from the airship's (gas-fuelled) engines, supporting it on the empty return leg. The ship's structure would have been "of a semi-monocoque type of stressed metal/skin honeycomb sandwich
Sandwich structured composite
A sandwich-structured composite is a special class of composite materials that is fabricated by attaching two thin but stiff skins to a lightweight but thick core...
construction."
The project was "terminated before a detailed study of the concept could be crystallised." AD's work "showed that the concept was impracticable" but "[brought] Aerospace Developments into contact with the latest materials and ideas."
Smaller airships and the Aerovision contract
A paper delivered by Munk to a Royal Aeronautical SocietyRoyal Aeronautical Society
The Royal Aeronautical Society, also known as the RAeS, is a multidisciplinary professional institution dedicated to the global aerospace community.-Function:...
symposium in 1975, dealing primarily with the Shell project, also makes reference to AD's "pursuing the development potential for relatively small non-rigid, advanced technology airships in the half to ten ton payload range for general freight, surveying and airborne jeep applications." These airships were to embody many of the innovative features eventually seen in the AD500 and Skyship 500/600, including vectored thrust and the use of modern materials such as Kevlar. Negotiations were stated to be in process with the governments of Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Ecuador and Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
concerning sales of such airships.
In a May 1976 Flight International
Flight International
Flight International is a global aerospace weekly publication produced in the UK. Founded in 1909, it is the world's oldest continuously published aviation news magazine...
article, Multi-Modal Transport Analysis, an associate of AD (the two firms shared offices in London, with "perhaps a dozen people working full-time" on the project), said contracts had been signed with Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
n company Aerovision for the construction and delivery in 1977 of an initial airship, with a further 21 (which would be "of similar design to the first ship, but...vary in payload and therefore size") to be delivered over the following 10 years. The first airships would be assembled and tested in Britain, with production being "transferred gradually to Venezuela." A family of five airship types was proposed:
- Type A: 0.51 tonne (0.501943801978249 LT) payload
- Type B: 1 tonne (0.984203533290685 LT) payload
- Type C: 5.1 tonnes (5 LT) payload
- Type D: 10 tonnes (9.8 LT) payload
- Type E: 20 – payload
The first airship (later to be designated the AD500) was to be of Type B. It would be used experimentally to supply isolated communities in Venezuela's interior and for night-time advertising flights to recoup the ship's cost.
The AD500
The rollout of the first ship was delayed, mainly by certification problems (certification required the Civil Aviation Authority to write a set of airworthinessAirworthiness
Airworthiness is a term used to describe whether an aircraft has been certified as suitable for safe flight. Certification is initially conferred by a Certificate of Airworthiness from a National Airworthiness Authority, and is maintained by performing required maintenance actions by a licensed...
requirements for airships, something that took six months) but also by factors including a change of envelope supplier and revision of the engine and propeller design. The AD500, as it was by then known, first flew from Cardington on 3 February 1979.
The AD500 was "a new-generation airship making use of advanced materials and technology." It was 164 feet (50 m) long and contained 181200 ft3 of helium. Materials used in the ship included thin single-ply polyester
Polyester
Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate...
, coated with titanium dioxide
Titanium dioxide
Titanium dioxide, also known as titanium oxide or titania, is the naturally occurring oxide of titanium, chemical formula . When used as a pigment, it is called titanium white, Pigment White 6, or CI 77891. Generally it comes in two different forms, rutile and anatase. It has a wide range of...
-polyurethane
Polyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
, for the envelope; Kevlar
Kevlar
Kevlar is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires...
for the cables suspending the gondola from the top of the envelope; a Kevlar nosecone moulded in the same manner as glass-reinforced plastic
Glass-reinforced plastic
Fiberglass , is a fiber reinforced polymer made of a plastic matrix reinforced by fine fibers of glass. It is also known as GFK ....
; and a gondola moulded by Vickers–Slingsby
Slingsby Aviation
Slingsby Aviation is a British aircraft company based in Kirkbymoorside, North Yorkshire, England. The Slingsby business was founded on the building and design of gliders and sailplanes. From the early 1930s to about 1970 it built over 50% of all British club gliders and had success at national and...
from Kevlar-reinforced plastic. Other innovations featured in the AD500 included simplified controls and thrust vectoring
Thrust vectoring
Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine or motor in order to control the attitude or angular velocity of the vehicle....
— an old airship idea revived — via inboard-mounted Porsche
Porsche PFM 3200
Porsche's PFM 3200 was a six-cylinder horizontally opposed air-cooled aircraft engine developed from their air-cooled line of automobile engines from the famous Porsche 911 sports car...
engines driving vectoring ducted fan
Ducted fan
A ducted fan is a propulsion arrangement whereby a fan, which is a type of propeller, is mounted within a cylindrical shroud or duct. The duct reduces losses in thrust from the tip vortices of the fan, and varying the cross-section of the duct allows the designer to advantageously affect the...
s.
Unfortunately, on 8 March 1979, the month-old AD500 was seriously damaged when the nosecone failed while the ship was moored in high winds. Aerovision subsequently withdrew its financial support, and AD was liquidated
Liquidation
In law, liquidation is the process by which a company is brought to an end, and the assets and property of the company redistributed. Liquidation is also sometimes referred to as winding-up or dissolution, although dissolution technically refers to the last stage of liquidation...
on 8 June.
The Airship Developments interlude
Following the loss of the AD500 prototype, the Aerospace Developments design team was reconstituted in September 1979 under the name Airship Developments Limited. During its short period under this name, the firm projected the following non-rigid airship designs (several of which echoed the earlier AD proposals):- AD15: a remotely piloted surveillance vehicleUnmanned aerial vehicleAn unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...
with a gas capacity of 150 cubic metres (5,297.2 cu ft) - AD100: a "runabout blimp" with 1000 cubic metres (35,314.7 cu ft) of gas
- AD500: a rebuilt version of the prototype
- AD600: an enlarged AD500 with a gas capacity of 6000 cubic metres (211,888 cu ft) (i.e. around 10% less than the eventual Skyship 600Skyship 600The Skyship 600 is a modern airship, originally designed by British company Airship Industries, and now owned and operated by Airship Management Services and Skycruise Switzerland AG.The first Skyship 600 made its maiden flight on 6 March 1984....
) - AD5000: an extremely large (by non-rigid standards) craft with 50000 cubic metres (1,765,733.3 cu ft) of gas and a payload of over 20 metric tons (19.7 LT), foreshadowing the later Sentinel 5000/YEZ-2A programme
Thermo-Skyships takeover
In May 1980, Airship Developments was acquired by Thermo-Skyships Ltd., a firm that had been working on lenticular airship designs (dubbed "flying saucers") that would have used heating of the lifting gas to control buoyancy. The resulting firm was known as Airship Industries Ltd.(AI). During the approximately two-and-a-half years the Thermo-Skyships team spent at AI, it proposed several abortive designs, discussed below, for (non-lenticular) rigid airships.Skyship 500
The AD500 was succeeded by the Skyship 500 model. The first flight of a Skyship 500 proper (i.e. excluding the AD500) took place from Cardington on 28 September 1981. The ship incorporated "many detail improvements" relative to the AD500, including a new envelope material, improved actuators, and an overall weight saving of around 140 kilograms (308.6 lb).Five more 500s were subsequently built — one at Cardington, two in Toronto, one in Tokyo, and one in the United States. The ships were mainly used in advertising and filming. However, other notable uses of the craft included sightseeing flights over London, a trial shuttle service between Paris's Orly and Charles de Gaulle airports, and trials with NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
and the United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
, United States Navy and United States Coast Guard
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the military branches for having a maritime law enforcement mission and a federal regulatory agency...
. Four 500s were later upgraded to 500HL standards by replacing the 500 envelope with a 600 one to increase lift for heavy payloads or hot and high
Hot and high
In aviation, hot and high is a condition of low air density due to high ambient temperature and high airport elevation. Air density decreases with increasing temperature and altitude. Lower air density reduces the amount of lift generated by the wings or the rotors of an aircraft, which may hamper...
applications. Additionally, two more 500 gondolas were commenced but never completed.
Proposed rigid airships—R40/R130 and R150
The former Thermo-Skyships design team proposed two rigid designs during their time with AI. In July 1980, AI announced "ambitious plans" to begin construction of a freight-carrying rigid, designated the Skyship R40, in early 1982. The airship (which appears also to have been referred to as the R130), was to be 183 metres (600.4 ft) long, contain 120000 cubic metre of gas and have a hull form resembling that of the 1920s British rigid R100R100
HM Airship R100 was a privately designed and built rigid airship made as part of a two-ship competition to develop new techniques for a projected larger commercial airship for use on British empire routes...
, with four Pratt & Whitney Canada PT6
Pratt & Whitney Canada PT6
The Pratt & Whitney Canada PT6 is one of the most popular turboprop aircraft engines in history, and is produced by Pratt & Whitney Canada. The PT6 family is particularly well known for its extremely high reliability, with MTBO's on the order of 9000 hours in some models. In US military use, they...
engines. It would have been capable of carrying payloads of up to 58 tonnes (57.1 LT).
Redcoat Air Cargo
Redcoat Air Cargo
Redcoat Air Cargo was a British cargo airline between 1977 and 1982 with headquarters at Horley in Sussex and an operating base at Luton Airport.-History:...
proposed acquiring four R40s by 1984 and "opt[ing] out permanently from conventional aircraft."
A second design, the R150, followed. The R150 was to have been 174 metres (570.9 ft) long, with 152000 cubic metre of gas and a payload of 75 tonnes (73.8 LT), and propelled by four Garrett AiResearch
Garrett AiResearch
Garrett AiResearch was a manufacturer of turboprop engines and turbochargers, and a pioneer in numerous aerospace technologies. It was previously known as Aircraft Tool and Supply Company, Garrett Supply Company, AiResearch Manufacturing Company, or simply AiResearch...
turboprops, with an additional Allison
Allison Engine Company
The Allison Engine Company was a U.S. aircraft engine manufacturer. In 1929, shortly after the death of James Allison, the company was purchased by the Fisher brothers. Fisher sold the company to General Motors, who owned it for most of its history...
turboshaft providing air to nose- and tail-mounted thrusters for purposes of low-speed control. The use of natural gas, or a combination of natural gas and LPG, as fuel was considered. Unlike the R40/R130, which was to have had a traditional rigid structure, the R150 was intended to be a metal-clad airship
Metal-clad airship
Metal-clad airships are airships which utilize a very thin, airtight metal envelope, rather than the usual rubber-coated fabric envelope. The shell may be either internally braced as with the designs of David Schwarz, or monocoque as in the ZMC-2...
, with a thin metal shell stabilised by an internal pressure of around 2 kilopascal (0.290075475467502 psi).
Federal Express (FedEx) was reportedly "negotiating the possible purchase of a non-rigid training airship" in early 1981, with the possibility of an order for "75-tonne payload R.150 cargo airships" to follow, and Redcoat—through which FedEx had approached AI—switched its order to the R150, ordering four airships with options
Option (aircraft purchasing)
An option, when purchasing aircraft, allows an airline to purchase additional aircraft in the future at an agreed price and date.When placing orders for new aircraft, airlines commonly obtain options from the aircraft manufacturer, for example Airbus or Boeing...
on another 10. FedEx was motivated by fuel-efficiency concerns and considered airships suitable for lower-priority 48-hour package deliveries.
However, FedEx stated in late 1981 that its airship plans had been "put aside for the time being" and Redcoat went into voluntary liquidation in mid-1982.
The R150 design was inherited by Wren Skyships when AI's rigid division was split off (see below), and Wren went on to propose new metal-clads of varying sizes.
Demerger of Wren Skyships
In late 1982, the former Thermo-Skyships was demerged from Airship Industries, becoming Wren Skyships (after founder Major Malcolm Wren) and relocating to Jurby airfieldRAF Jurby
Royal Air Force Station Jurby was a former RAF station built in the north west of the Isle of Man. It was opened in 1939 on of land acquired by the Air Ministry in 1937, under the control of No. 29 Group, RAF...
on the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
. The firm continued metal-clad development and began work on a non-rigid design, the Advanced Non-Rigid (ANR). Wren Skyships became the Advanced Airship Corporation (AAC) in 1988. Construction of the prototype ANR was commenced, but envelope problems delayed its completion, and AAC went into liquidation during the early 1990s recession.
Skyship 600
Elizabeth City, North Carolina
Elizabeth City is a city in Pasquotank County and Camden County in the State of North Carolina. With a population of 18,683 at the 2010 census, Elizabeth City is the county seat of Pasquotank County....
; one at Sydney; two in Japan; and one at Lakehurst, New Jersey
Lakehurst, New Jersey
Lakehurst is a Borough in Ocean County, New Jersey, United States. As of the United States 2010 Census, the borough population was 2,654.Lakehurst was incorporated as a borough by an Act of the New Jersey Legislature on April 7, 1921, from portions of Manchester Township, based on the results of a...
. As was the case with the 500, two additional gondolas were commenced but never completed.
Like the 500, the 600 was employed in the traditional blimp role as an advertising and camera platform and tested in a variety of other civil and military roles. The sightseeing operations begun with the 500 were expanded to take in a number of additional cities worldwide, including Paris, Toronto, Montreal
Montreal
Montreal is a city in Canada. It is the largest city in the province of Quebec, the second-largest city in Canada and the seventh largest in North America...
, Sydney, Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...
, Melbourne, San Francisco and Zurich
Zürich
Zurich is the largest city in Switzerland and the capital of the canton of Zurich. It is located in central Switzerland at the northwestern tip of Lake Zurich...
, as well as London.
Financial issues
At the time when the first 600 flew, AI was seeking to raise capital for continued operations. A £5.5 million rights issueRights issue
A rights issue is an issue of additional shares by a company to raise capital under a seasoned equity offering. The rights issue is a special form of shelf offering or shelf registration. With the issued rights, existing shareholders have the privilege to buy a specified number of new shares from...
in 1983 was followed by a second for £7 million, this time underwritten by Alan Bond
Alan Bond (businessman)
Alan Bond is an Australian businessman noted for his criminal convictions and high-profile business dealings, including what was at the time the biggest corporate collapse in Australian history. Bond was born in the Hammersmith district of London, England, and emigrated to Australia with his...
's Bond Corporation, the following year. The firm had posted a £2.3 million loss for the six months to 30 September 1983, as a result of delays in the 500's testing and certification, difficulties in setting up a Canadian subsidiary and revenue lost due to the certification delays. It had lost almost £10 million between June 1978 and September 1983, and its share price fell from a 1983 high of 147p to 56p in March 1984. However, AI reported its first profit, some £50,000, in the 15 months to 30 June 1985.
The Sentinel 5000/YEZ-2A programme
In February 1985, the United States Navy (USN) issued a request for proposalRequest for Proposal
A request for proposal is issued at an early stage in a procurement process, where an invitation is presented for suppliers, often through a bidding process, to submit a proposal on a specific commodity or service. The RFP process brings structure to the procurement decision and is meant to...
for a radar-carrying Battle Surveillance Airship System (BSAS). AI responded with the Skyship 5000, "a concept airship of about 70000 cubic metre" The BSAS programme was subsequently renamed the Naval Airship Surveillance Program (NASP), then the Organic Long Endurance Airborne Area Surveillance Airship System, and finally became the Naval Airship Program. In mid-1985, the Naval Air Development Center awarded three six-month contracts for further studies to, respectively, Goodyear Aerospace, Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
paired with Wren Skyships, and Westinghouse paired with AI. The Navy was reported to be "interested in up to 75 airships." On 5 June 1987, Westinghouse–Airship Industries (WAI) won the contract to build an Operational Development Model (ODM), or prototype, with the possibility of a production run of 40–50 airships if the ODM proved successful in trials. However, NASP was cut from the fiscal year 1989 defence budget. Congress later authorised funding to continue the ODM's development, and the Defense Advanced Research Projects Agency
Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency is an agency of the United States Department of Defense responsible for the development of new technology for use by the military...
inherited the programme from the Navy.
In the design proposed in 1989, the Sentinel 5000, designated the YEZ-2A by the Navy, would have been 143 metres (469.2 ft) long and 32 metres (105 ft) in diameter, containing 70864 cubic metre of helium. A crew of 10–15 would have been accommodated in a triple-decked, partly pressurised gondola, on top of which (within the envelope) the radar antenna was to be mounted. The ship would have been powered by two CRM diesel engines, with a supplementary General Electric T700 turboprop for "dash" situations. It would have offered an unrefuelled endurance of two to three days, which could be extended to 30 days through refuelling and replenishment from surface ships.
AI produced a smaller airship, the Sentinel 1000, as part of the development programme. The 1000 was a half-linear-scale model of the 5000, having a modified Skyship 600 gondola but a larger (10000 cubic metre) envelope and an empennage
Empennage
The empennage , also known as the tail or tail assembly, of most aircraft gives stability to the aircraft, in a similar way to the feathers on an arrow...
resembling the "X" form planned for the 5000, rather than the cruciform one of the 600. Other features included fly-by-light controls, an envelope material that eliminated the need for routine hangaring and a ground-handling technique that required a comparatively small crew of eight. However, the ship, which was assembled at WAI's Weeksville facility in North Carolina, did not fly until 26 June 1991, by which time AI had collapsed and Westinghouse had taken full control of the programme.
From an early stage of the programme, AI contemplated a civil version of the 5000, variously reported as accommodating between 140 and 300 passengers, for applications including both luxury shuttle services and conventional scheduled flights. However, this project was dependent on the success of the military programme.
The end of Airship Industries
AI made a loss of £15 million in the year to 30 June 1989, compared to £3.7 million in the preceding year and £5.1 million the year before that. In early 1990, after refinancingRefinancing
Refinancing may refer to the replacement of an existing debt obligation with a debt obligation under different terms. The terms and conditions of refinancing may vary widely by country, province, or state, based on several economic factors such as, inherent risk, projected risk, political...
efforts failed, the firm sought to improve its financial position through a sale and leaseback of the Cardington facilities, an attempted sale of its U.S. operations to Lou Pearlman
Lou Pearlman
Louis Jay "Lou" Pearlman is a former impresario of the successful 1990s boy bands such as The Backstreet Boys, *NSYNC, Take 5, O-Town and US5. In 2006, it was discovered that Pearlman had perpetrated one of the largest and longest-running Ponzi schemes in American history, leaving more than $300...
's Airship International, and efforts to renegotiate the YEZ-2A contract from fixed price
Fixed price
The term "fixed price" is a phrase used in the English language to mean that no bargaining is allowed over the price of a good or, less commonly, a service...
to cost plus
Cost-plus contract
A cost-plus contract, also termed a Cost Reimbursement Contract, is a contract where a contractor is paid for all of its allowed expenses to a set limit plus additional payment to allow for a profit. Cost-reimbursement contracts contrast with fixed-price contract, in which the contractor is paid a...
. However, trading in AI's Isle of Man–based holding company was suspended in August 1990, and administrative receivers were appointed in September.
Slingsby acquired the marketing and intellectual property rights to the civil versions of the 500, 500HL and 600—except in North America, where Airship International was the appointed agent—as well as work in progress, plant and fixed assets and UK, U.S., and Japanese type certificate
Type certificate
A Type Certificate, is awarded by aviation regulating bodies to aerospace manufacturers after it has been established that the particular design of a civil aircraft, engine, or propeller has fulfilled the regulating bodies' current prevailing airworthiness requirements for the safe conduct of...
s. Westinghouse acquired the corresponding rights to military variants of the three designs and took full control of the YEZ-2A programme. Airship International acquired the share capital of AI's U.S. operation, one complete and one incomplete 600, an incomplete 500HL and support equipment. The rights held by Airship International subsequently passed to Airship Management Services
Airship Management Services
Airship Management Services, Inc. builds, owns and operates Airship Industries Skyship and Sentinel type airships. AMS, run by George Spyrou, and through associated companies in the U.S., Europe and Japan, provides technical and operational support to airships worldwide...
.
Westinghouse Airships and the fate of the Sentinel programme
As discussed above, Westinghouse took full control of the Sentinel programme after the failure of Airship Industries, and the first flight of the Sentinel 1000 took place under Westinghouse's management in 1991. The type certificates for the 500HL and 600 designs, which had initially passed to Slingsby, were acquired by Westinghouse in 1993.Aside from the Sentinel 1000's role as a demonstrator for the 5000, Westinghouse promoted the 1000 itself for roles such as demonstrating over-the-horizon targeting
Over-the-horizon radar
Over-the-horizon radar, or OTH , is a design concept for radar systems to allow them to detect targets at very long ranges, typically up to thousands of kilometers...
and acting as a sensor platform for drug interdiction. The UK's Ministry of Defence
Ministry of Defence (United Kingdom)
The Ministry of Defence is the United Kingdom government department responsible for implementation of government defence policy and is the headquarters of the British Armed Forces....
reportedly sent pilots to the U.S. in early 1992 to evaluate the airship. In late 1993, the Sentinel 1000 became the first aircraft with fly-by-light controls to receive FAA
Federal Aviation Administration
The Federal Aviation Administration is the national aviation authority of the United States. An agency of the United States Department of Transportation, it has authority to regulate and oversee all aspects of civil aviation in the U.S...
certification and possibly the first such aircraft to be certificated anywhere.
In 1993, Westinghouse was "still hopeful" that a prototype YEZ-2A would fly in 1998. The roles envisaged at this stage were "radar surveillance in support of U.S. Navy fleet operations and theatre missile-defence for the U.S. Army." The prototype would have been constructed at Moffett Field, California.
On 2 August 1995, a fire, apparently started accidentally during welding work, destroyed the Weeksville hangar and its contents, including the sole Sentinel 1000 and the mock-up of the 5000's gondola. Despite the setback, work on the 5000 project continued, and the firm projected an airship somewhat larger than the 1000, the Sentinel 1240, which would have been capable of accommodating 40 passengers. Changes to the 5000's design were also proposed, including a simpler, single-deck, gondola and the replacement of the two gondola-mounted diesel engines and one turboprop with three Zoche diesels, two mounted on a beam spanning across the envelope and one at the tail. Both Moffett Field and Lakehurst were under consideration as construction locations. However, further plans were stymied by the sale of Westinghouse's defence-electronics business to Northrop Grumman
Northrop Grumman
Northrop Grumman Corporation is an American global aerospace and defense technology company formed by the 1994 purchase of Grumman by Northrop. The company was the fourth-largest defense contractor in the world as of 2010, and the largest builder of naval vessels. Northrop Grumman employs over...
in early 1996. Westinghouse Airships did not form part of this deal; its designs, patents, and other assets were subsequently acquired by British investor group London Wall, in a deal led by Roger Munk.
ATG and its successors
The successor company became known as Airship Technologies, later becoming Advanced Technologies Group (ATG). Although ATG received two orders for the Skyship 600B, a higher-performance version of the 600, in its early years, it sold the type certificate for the 600 to Julian Benscher of Global Skyship and concentrated instead on a new product line. The firm constructed a solitary example of its AT-10 airship, a small non-rigid 40.3 metres (132.2 ft) long with a gas volume of 2306 cubic metre, i.e. somewhat less than half the Skyship 500's volume. It also projected unrealised non-rigids, such as the 50-seat AT-04, and undertook development work on a hybrid airshipHybrid airship
"A hybrid airship is an aircraft that combines characteristics of heavier-than-air technology, fixed-wing aircraft or helicopter, and lighter-than-air , aerostat technology."[1]Examples include helicopter/airship hybrids intended for heavy lift applications and dynamic lift airships intended for...
, the SkyCat
SkyCat
SkyCat is a class of proposed heavy-lift and ultra-heavy-lift hybrid aircraft which derive more than half of their lift by helium buoyancy and the balance via aerodynamic lift produced by aerodynamic shaping. Such vehicles are not "payload specific"...
.
After ATG went into administration, its assets were acquired in 2006 by an Italian–British consortium and the new business named SkyCat Group. However, SkyCat Group itself went into administration about a year later, and its assets were acquired by a new firm, Hybrid Air Vehicles (HAV), set up by British investors. , HAV continues to develop the SkyCat. HAV and partner Northrop Grumman won a $517 million LEMV contract to build 3 HAV 304's for the US Army in Afghanistan. The first one will fly later this year and will be the biggest aircraft in the world.