Mr. Nigel KALEY (United Kingdom) THE MODERN AIRSHIP: A REVIEW OF 40 YEARS OF AIRSHIP DEVELOPMENT. August 1962 marked the final closure of the United States Navy’s airship program. It was presumed by the majority of US Government and Navy officials, not to mention the world’s aviation press, that this marked the end of the airship in any practical capacity. The final chapter had been written, given that the last country to actually employ airships in a military role had now also decided to abandon them. The airship as an operational vehicle was now to be relegated to the pages of history; more extinct even than that other great symbol of a bygone age…the Square Rig Sailing Ship. But the airship has refused to die, and in the 4 decades since the demise of the US Naval Airship Program, there has been a dizzying number of designs put forward for myriad potential operations around the globe. Unfortunately, however, despite numerous highly detailed studies costing a great deal of money, there have been all too few airships actually built and flown since the early 1960’s. With this work I intend to examine the course of international airship development since August 1962, and scrutinize all of the important projects and designs that have been proposed in the intervening decades. I personally am guardedly optimistic concerning the potential use of the airship in the 21st Century, but I believe there is much to be learned from the experiences of recent times. Even as the US Navy’s program was being wound down, there were already several projects being formulated in America. The first of these became public knowledge in September 1962. The AEREON III, a triple-hulled rigid, was the product of the Aereon Corporation of Princeton, New Jersey, and was the work of their principal designer John Fitzpatrick. The Aereon Corporation, founded in 1959, was somewhat unique in that its original inspiration was as much spiritual as it was grounded in sound engineering methodology. The founder of the company, the Reverend Monroe Drew, had great visions as to the humanitarian value of airships, and he took his lead from the example of an eccentric American inventor of the late 19th Century. Dr. Solomen Andrews had, it was true, achieved a degree of controlled flight with his unique un-powered airship, AEREON I. The AEREON was basically a tri-lobed balloon that generated a large degree of dynamic lift. Through extremely skilful handling of the balloon into wind, and by careful release of ballast and gas, Dr. Andrews had successfully demonstrated relatively controlled flight in a long, circular

flight-path, to the astonishment of the citizens of New York below. Rev. Drew was highly impressed by the original AEREON, and wished to ultimately see a fleet of such craft able to deliver relief to areas affected by natural disaster. Through vigorous campaigning, Rev. Drew was able to raise sufficient capital to set up the Corporation, and to take on a rudimentary design staff. His chief designer, John Fitzpatrick, was fortunately able to convince Drew as to the necessity of updating the AEREON concept, as the latter had been intent on making the design an un-powered craft as in Dr. Andrews original concept. Fitzpatrick’s pragmatism held the day, and the new AEREON became a powered vehicle, although the triple-hulled configuration of the original was retained. The idea was to make a gasfilled aerofoil as efficient as was practical, and to make full use of all of the technological advances of recent years. AEREON III was comprised of 3 streamline rigid hulls 83ft (25.2m) long, and 175ft (53.3m) in diameter. The hulls were connected in parallel by a structure of airfoil section and the completed vehicle had a maximum width of 55 ft (16.7m). The hulls closely resembled Zeppelin practice, with 7 main rings with radial wire bracing and 3 intermediate rings between each main frame. There were 20 longitudinals of duralumin tubing featuring shear wire bracing. The 18 gas cells, manufactured from Tedlar plastic, were fitted with manoeuvring and automatic valves. The hybrid airship was intended to be 400lb heavy when filled at 85% helium capacity, and the helium was to be heated by propane burners under each gas cell so that it could fly without releasing gas or ballast. The 21ft (6.4m)2 bladed helicopter rotor being used as a propeller was to be powered by a 80hp Solar Gas turbine. 2 pilots would occupy the glassed-in cockpit in the nose of the central hull and operate the elevators between the hulls astern, and the 2 rudders attached to the large fins beneath the outboard hulls aft. Unfortunately the designers and builders of AEREON III had numerous problems to surmount, not the least of which was the constant financial pressure that the company was under. AEREON III never actually flew, and she was wrecked during her taxiing trials in April 1966. The Airship was caught by a sudden gust of wind during a sharp turn that flipped the fragile, lightweight vehicle over on to its back and then back on to its undercarriage. The airship was very badly damaged and, after an attempt at a re-build in a new configuration, was finally dismantled sometime in 1967. The company was now in a perilous state financially, and it was almost destroyed by a serious and protracted investigation by the Securities and Exchange Commission into possibly fraudulent stock floatation. The investigation did, however, trigger a large scale restructuring of the company that almost certainly saved it from dissolution in the long term. Rev. Drew was the most significant victim of the re-structuring that saw him removed from his position of authority and relegated to the sidelines of the company that he founded. His successor, William Miller, gradually nurtured the company, and oversaw the subsequent

development of the original AEREON III design, but it was to be sometime before these renewed plans were to be made public.

However, another US project had already received a great deal of publicity by the mid 1960’s, namely the nuclear-powered rigid airship design of Professor Francis Morse of Boston University. Prof. Morse had long been fascinated in rigid airship design and technology, and had some experience as an engineer with the Goodyear Aircraft

Corporation. Indeed, Morse’s interest can be traced back to his student days, when he wrote his thesis “The Rigid Airship Andromeda “ back in the 1940’s.

The nuclear-powered rigid airship had been introduced to the American public in a series of articles featured in the magazine “Popular Mechanics” by Frank Tinsley, and the writings of Edwin J. Kirschner, author of “The Zeppelin in the Atomic Age”. Prof. Morse’s detailed design was first publicised at the 1963 World’s Fair. The airship was to be 980ft (298.7m) long and 172ft (52.4m) in diameter, with a volume of some 12,500,000cu ft (353,960cu m) of helium. It was designed to carry up to 400 passengers in absolute luxury at a top speed of 103mph (89.5kts). Morse planned to have 5 cargo holds, each of 80,000cu ft (2,265cu m) volume, space for an 18 passenger aeroplane ferry and finally, some 40,000sq ft (3,716sq m) of passenger accommodations spread out over 3 decks. The structure of the Morse design was essentially conventional, and the airship strongly resembled the British R101 in its outward appearance. Indeed, Morse seemed to borrow various features from both R100 and R101. The use of only 16 main longitudinal girders, with “reefing girders” between them to stretch out the outer cover was very reminiscent of R101, whereas the employment of a bow-to-stern axial corridor was more characteristic of R100. The structural weight of the Morse Nuclear Rigid was worked out at a precise 76.2tns (168,000lbs) with gross lift at 95% inflation given as 344.7tns (760,000lbs). The useful lift was given as some 136tns (300,000lbs) with an actual available payload of 81.6tns (180,000lbs). The nuclear powerplant was to drive 3 engines at the stern of the airship: a 4,000hp gas-turbine for the 60ft (18.2m) long dual rotation propellers, and two 1,000hp turbofans for the boundary layer control ducts installed aft. The reactor was to have been some 630ft (192m) back from the nose of the airship in an expansion of the axial corridor. The entire installation with shielding was to be enclosed in a pressurised steel sphere, 13ft (3.9m) in diameter, with a total weight of 50tns (110,231lbs). This would still have come in under the weight of conventional fuel needed for long flights in a comparable airship with internal combustion engines. The Morse proposal did attract considerable interest for sometime, and it was extensively featured in the popular press of both Europe and the US. It gained a degree of public acceptance with the enthusiasm and vogue for all things “atomic” I the 1960’s, but no practical steps were ever taken to make the design a reality. Indeed, no company was set up to actually build the Morse design, despite it appearing to be technically feasible. America wasn’t the only country proposing to re-evaluate the airship in the 1960’s, far from it. By the middle of the decade another nuclear proposal had appeared in the national press of the country that was, and always will be synonymous with the giant rigid airship and indeed the land of its birth; Germany. The proposal of Erich von Veress (actually an Austrian engineer based in Graz) was incredibly ambitious, combining nuclear propulsion

with other radical innovations. The ALV-1 (standing for Atom Luftschiff Veress) was to be of conventional airship shape, with 4 stabilizing fins and control surfaces at the stern. The airship was to be 1,062ft (324 m) in length, with a diameter of 177ft (54m) and a maximum gas volume of 14,400,000cu ft (408,000cu m). Veress reckoned on a gross helium lift of some 455 tonnes (1,003,103lbs), so that 500 passengers and 100 crew, plus 100 tonnes (220,462lbs) of freight, could be carried at a maximum speed of 187mph (162kts).

One of the most controversial aspects of the Veress design concerned the proposed method of propulsion. Basically, the airship was to use a new and unique system of boundary layer control that would energise and maintain an attached turbulent boundary layer over the entire after part of the hull. At the bow, Veress proposed an axial tunnel, 21.3ft (6.5m) in diameter, and a large multibladed propeller that was to be electrically driven. The slipstream of this propeller was to cling to the nose contour of the airship’s hull back to its point of maximum diameter, where it would tend to separate forward of this area. However, a ring of nozzles was to discharge into the boundary layer the air that has been drawn in through the tunnel in

the nose by a propeller driven by a gas-turbine that was to use reactor-heated helium as its working fuel.The airship’s nuclear reactor was to be fuelled with highly enriched uranium, moderated with beryllium and reflected by graphite. It was to be 6.6ft (2m) high, and 3.93ft (1.2m) in diameter and contained in a domed-head cylindrical pressure vessel of steel, (10cm) thick and lined with 3cm of boron-steel. Veress produced a whole series of beautifully drafted diagrams to illustrate his design, but it soon came under the intense scrutiny of critics. The weights for the airship simply did not add up, one critic calculating that the total empty weight for the airship, excluding fittings and the propulsion system, came to some 275 tonnes (220,462lbs) out of a gross lift of 455 tonnes (1,003,103.lbs). This left only 180 tonnes (396,832.lbs) of lift for the propulsion system (minus the reactor, shield and gas turbine), gas cells, controls and instruments, compartments and passenger accommodations to hotel standard, plus 100 crew, 500 actual passengers and the promised 100 tonnes (396,832.lbs) of additional freight. Clearly the numbers just did not make sense. Most critics had serious reservations concerning Veress’ boundary layer propulsion system, and it was never really taken seriously by the small band of professional engineers engaged in airship research in Germany. There were several disadvantages with both the Morse and Veress nuclear proposals, and in particular, the loading of the 2 designs would appear to be suspect. The weights for both of these nuclear powered airships were to have been concentrated in the bow and tail which may well have proved problematic. Airship loading is a very exact science, and the spreading of the total load over the airship is of crucial importance. This would appear to have been somewhat neglected in both the Morse and Veress proposals. Veress, however, was not so easily dissuaded, and he continued to make refinements to his design right up until his death in the mid-1970’s. He would make periodic appearances at various airship conferences, but was never able to silence the critics of his design. He was certainly unable to raise any serious financial support for his proposal, and it rather inevitably remained an unbuilt dream at the time of his death. However, airships of a more conventional design were being formulated on a select few German drawing boards at the close of the 1960’s, largely at the behest of engineer enthusiasts who wanted to see a revival of the airship industry in Germany. Karl-Heinz Albrecht, an engineer who had links with the airship designer Gustav Unger and had worked with Albert Simon on his revived “Wasserluftschiff” (Waterairship) project of the 1950’s, was behind much of this activity. He had formed the Verein für Luftschiffahrt e.V. in 1963 with a group of fellow engineers with the express purpose of furthering the airship cause in Germany. Although the original group collapsed within a year due to a serious difference of opinion, Herr Albrecht would make periodic calls for a new “Zeppelin Spende” to fund a renewed program of airship construction in Germany. He was hoping that the German people’s natural fascination and enthusiasm for airships would lead to a willingness to contribute to a National Airship Fund, such as had saved the Zeppelin Company in1908. Unfortunately, however, the German people’s enthusiasm for airships did not, in the 1960’s, stretch so far as volunteering large-scale cash donations to finance their construction, and Herr Albrecht’s patriotic call for funding largely went unanswered. All the same, Karl-Heinz Albrecht produced a variety of different airship designs for a number of varying operational roles throughout the 1960’s and through to almost the close of the century. On the whole, his designs tended to fall into 2 different categories; either a rigid, centrally-spined airship based on the designs of Gustav Unger, or large semi-rigids

that were highly reminiscent of the earlier “Wasserluftschiff” proposals. Unfortunately, Albrecht never produced any detailed plans or calculations in support of these designs, and they were subsequently dismissed as being the work of an enthusiastic amateur which was perhaps rather unfair to Herr Albrecht. He was to re-appear in the middle 1970’s with another project, of which we shall hear more in due course. The 1960’s also saw a groundswell of support growing for the airship’s revival in Soviet Russia. Actual work on airship designs had begun in 1955 in response to a 5 year plan directive to improve transportation in remote areas. A design had been presented to the Committee on Inventions and it was actually approved in 1961. Technical details of this design are unfortunately not readily available. However, a Commission on Lighter-than-Air Navigation had been set up by the Leningrad branch of the Geographic Society of the Academy of Sciences of the USSR in 1957. Branch offices followed in several other cities. In 1961 the All-Union Geographic Society created a Volunteer Dirigible Design Bureau (OKB) in Leningrad. The impetus for the airship revival was so popular by 1965 that an AllUnion Conference for the Future of Dirigible Construction was held in Novosibirsk. The Conference was quite the success, and snippets of information even reached the Western media in both Europe and the US. This marked the first international confirmation, of sorts, that airships were once again on the agenda in the Soviet Union. From the point of an overview of modern airship development, we must concentrate our attention on the work of the Ukrainian Volunteer Dirigible Design Bureau, the Kiev Design Group, and their remarkable designs; the D-1 and D-4. The Kiev group were a particularly talented assembly of engineers, with a keen understanding of the possibilities, and limitations, of the modern airship. Some details of their D-1 design were first made available in 1967. I will not presume to go into too great a technical description of the D-1 and D-4, given that I am now writing at the behest of those very same highly talented individuals who conceived of them in the first place. I would instead refer the reader to the excellent article written by our esteemed editor, Mr. Alexander Polyanker, in the first edition of the Montgolfier Journal, entitled “Is Aerostation Able to Favour State Prosperity and Defence or Briefly about Project of Aerostatic Atmosphere Opening -Up System”. This article contains a most clear and concise description of the D-1 and D-4 development, and the technical capabilities of the 2 designs. However, I feel it would not be amiss to examine some of the D-1’s unique features (applicable to the whole series of airships that derive from the D-1 template), and consider their place in airship development. One of the most immediately arresting features of the D-1/D-4 concept in comparison with other modern airship proposals is the degree to which the designers have tried to think through a fully integrated system. A highly original method of mooring the airships is proposed that is beautifully economical and tidy. The system as a whole is designed for simplicity of operation, and to allow the maximum of airships (12) to operate from the minimum area of land. The traditional airship shed is seen as a construction and overhaul facility, and the airships are to spend most of their operational life at the mooring facility. The whole system could be compared with commercial bus and coach operations in that the airships are designed to operate on a day to day basis from terminals, or stations, and only periodically be returned to their shed for repair and servicing. This is most important as it should encourage greater flexibility of operations. It is envisaged that the airship terminals will be far more economical to construct than large-scale airship sheds. Each terminal would allow for up to 12 airships to operate, all of which are to be serviced by a single shed to be

built on the periphery of the site. The economic benefits and possibilities are readily apparent. But what of the actual design of the D-1 and its derivatives, and how does it compare with the more traditional of airship schemes? The D-1 utilises a rigid semi-monocoque hull to be made of polymer (glass, carbon etc) composite materials in a honeycomb sandwich. From the very outset of the construction process, the D-1 has a definite advantage over the old Zeppelin type of rigid airship in that the manufacture of the rigid shell is far more mechanised (although utilising essentially simple machinery) than the highly complex and labour intensive process of building a traditional rigid airship. From the viewpoint of construction costs alone, the D-1 makes for a far more attractive proposition than building a modernised Zeppelin type. The D-1 type of hull construction also makes for certain key advantages during service in that it allows for the possibility of affecting lift control via a number of internal gas compartments featuring electric valves, and an air ballast system that is set between these compartments and the rigid shell of the airship. There is also the promise of the airship being able to operate at favourably high altitude, without a decrease in operational payload, due to a special soft “supershell” that will allow for expansion of the gas without having to valve any away to the atmosphere. Such features give the D-1 an incalculable operational advantage over traditional airships, and the rigid shell is also superior from a care and maintenance point of view. It allows for the possibility of increasing mechanisation to be employed in cleaning and maintaining the hull, with favourable operational savings to be made accordingly. However, perhaps the most important point with the D-1 design is the inherent flexibility that it provides for scaling up the size of airship. Many of the modern-era airship projects, including the recent CargoLifter debacle, have been seriously hampered by their scale. Whilst it is certainly true that airships become more efficient the bigger they are, it is nevertheless an unfortunate truism that potential investors are put off by the sheer size and scale of potential airship developments. The costs involved, and consequent risks to the investor, are simply vast. Indeed, the CargoLifter project was well funded, but the costs of traditional airship facilities were so great as to sink the venture before construction had even begun on the airship itself. The D-1 is essentially a scaled down prototype of the D-4, designed to illustrate the potential operational performance of the type. At a gas volume of some 971,153cu ft (27,500cu m), and useful lift of some 14 tonnes (30,864.7lbs), the D-1 is the smallest effective unit of the type capable of serviceable operation. It is designed to be both an effective proving ground for the technology of the type, and a profitable working vehicle capable of undertaking specific missions. In this light it was hoped that the D-1 would make for a convincing demonstrator for the feasibility of a full-scale Soviet Airship Industry. Unfortunately, to date the D-1 must remain relegated with those many other airship designs that exist solely on paper. The reasons for the failure of the project back in Soviet Russia are both complex and obscure, although some facts are known. The Soviet Ministry of Aviation Industry (MAP) appeared to control most of the Resource and Development funding in the USSR. Furthermore, the Ministry tended to reject such radical changes in technology, particularly if such changes were initiated from the outside. In the case of airship design, the Ministry would appear to have resisted what it apparently considered to be an intrusion from the outside. However, it is a great testament to the engineers and designers behind the D-1 and its derivatives that their faith and belief in their design has

never wavered. Indeed, the design was systematically re-submitted for approval throughout the 1970’s and is, even as I write, still actively being promoted by the members of Aeroplast today. It is hoped, by this writer at least, that their faith and tenacity is finally rewarded with the construction of a D-1 demonstrator. Around the same time that details of the D-1 were first being made available by the Kiev Design Group in 1967, airship activity was again being mooted in the US. The restructured Aereon Corporation, now securely led by the aforementioned William Miller Jr., presented its new vision of a dynamic lift airship, the AEREON 340, sometimes referred to as the “Dynairship”. Although John Fitzpatrick was still closely involved in the design process of the AEREON 340, the company had by now a new chief engineer in the form of Juergen Bock. Formerly with Focke-Wulf in Germany, and latterly a physicist with the American Space Program, Bock was a formidable engineering talent with a genuine interest and belief in airships. Indeed, as we shall see later, the airship was in fact to become his life’s work. Following the accident to AEREON III in mid-1966, the initial repairs of the triple-hull design had soon become instead a reconstruction into the proposed AEREON IIIB. The IIIB would have been substantially larger being 100ft (30.4m) long and 75ft (22.8m) in span than the original configuration with a metalclad, partially delta shape. However, it soon became apparent that Bock and his engineers were rapidly outdistan cing the reconstru ction with new design potential. The research and computation were pushing the design in 1 consistent direction that resulted in the AEREON 340 configuration. The “340” referred to a lifting-body airship of 340ft (100m) length, with a wing span of 256ft (77m). It was to have been a commercial freight transport vehicle, specifically designed to handle modern standard size inter-modal containers. The cargo area was to contain built-in lifting and handling equipment to

accommodate up to 6 fully loaded trailers or containers of the same size. The total lift of the design was worked out at approximately 181.4tns (400,000lbs) (compared to the 31.75tns/70,000lbs nominal lift of the 340ft/103.6m long US Navy’s ZPG-2 non-rigid airship). The hybrid was to be powered with four 5,500hp Rolls Royce Tyne Turbo-Prop engines (seemingly the engine of choice for airship and hybrid airship projects of the time), mounted along the rear wing edge of the delta shaped aerobody. The helium lifting gas would be carried internally in large individual cells, and the design was intended to operate just slightly heavier-than-air. Aereon expected that 5 men would be sufficient to crew these semi-buoyant aircraft. Aereon were, perhaps wisely, rather publicity shy following the accident to the AEREON II, and the company maintained a low profile as they further developed their concepts. A flying model, the AEREON 7, was built to test the lifting-body design, and progress was gradually made. In the new design, helium would be largely ineffective to all intents and purposes until a certain scale was reached, and so it was not included in either the model AEREON 7 or the later piloted tests of the AEREON 26. AEREON 7 was tested in flight some 14 times, finally to destruction, but she proved an invaluable learning aid to the ongoing program. Of course the culmination of Aereon’s work came in 1970 with the manned flights of the AEREON 26; a 27ft (8m) long scaled down model of the lifting-body airship intended to prove the design’s inherent viability and investigate the particular flight characteristics of this unique new type of aircraft. The initial flights did provide much in the way of valuable information, but were also somewhat disappointing in that the vehicle was unable to get out of ground effect. However, following stringent measures to reduce weight, including the removal of the parachute, the radio, and fire extinguisher, as well as half of the fuel load, the 26 made its first real flight on September 28th. A series of successful test flights were made in Spring 1971 that provided the Aereon team with a wealth of data. Unfortunately the long hoped for development funding was not forthcoming, and the Aereon 340 was destined to be another paper-only concept that to date remains unbuilt. The Aereon Corporation, however, is still in business today, and is currently advocating a new and updated “Dynairship” for the 21st Century. The significance of the design must also be recognised, and it proved to be both influential and rather prophetic of the trend towards hybrid airship designs that became prevalent in the 1970’s. It should be mentioned here that the Goodyear Aircraft Corporation were also still involved in airship activity. They of course continued to operate their small fleet of

commercial, promotional blimps, and did maintain a consistent, albeit reduced program of airship development. GAC produced several important studies into un-manned, high-altitude airships at this time, and were also involved in the “Silent Joe” project, about which relatively little is known still. “Silent Joe” was a US Navy project under the auspices of the Advanced Projects and Research Agency (DARPA) to assess the practicality of developing a stealth-airship, with stern-mounted propellers. The Navy was looking for a silent and virtually undetectable aircraft capable of use in the Vietnam theatre of war, and specifically to operate over the Ho Chi Minh Trail at night attacking truck convoys. Goodyear provided the program with 1 of their commercial non-rigids, the Mayflower, and fitted it with a gimballed stern propeller for a series of tests. The results of these tests have never been made public, but it is widely held in airship circles that they did show promise, but also indicated the scale of innovation that would be required to meet the Navy’s stated requirements. “Silent Joe” was wound down in 1969 after the completion of the test-flights with the Mayflower and initial reports had been submitted. Goodyear also produced several noteworthy new concepts for passenger carrying designs, and the most visible of these was probably the Dynastat in the late 1960’s. The Dynastat was envisaged as the core component of a potentially new system of transportation to serve the North American mainland for the 1970’s and beyond. The fundamental idea involved short-haul intercity operations, and GAC studies found that a new concept of modified airship/aeroplane hybrid (shades of Aereon here) could readily satisfy short haul requirements. Vertical take-off and landing (VTOL) was deemed essential to eliminate the need for an airport, and silent operation was also seen as a necessity if operations were to be proximate to populated ares. The resulting vehicle was named the VTOL Dynastat: a lighter-than-air dynamic lift aircraft with vertical take-off and landing capability.

(To be continue)