This post was updated on 18 April 2019.
For more than two decades, there has been significant interest in the use of modern lighter-than-air craft and hybrid airships in a variety of military, commercial and other roles, including:
- Heavy cargo carriers serving remote and/or unimproved sites
- Persistent optionally-manned surveillance platforms
- Maritime surveillance / search and rescue
- Disaster relief, particularly in areas not easily accessible by other means
- Unmanned aerial vehicle (UAV) / unmanned air system (UAS) carrier
- Commercial flying cruise liner
One of the very significant factors driving interest in modern airships is that they offer the potential to link isolated regions with the rest of the world while doing so in a way that has lower environmental impact than other transportation alternatives for those regions. This issue is described well in a 21 February 2016 article by Jeanne Marie Laskas, “Helium Dreams – A new generation of airships is born,” which is posted on The New Yorker website, along with the following very optimistic airship concept drawing, at the following link:
In spite of the significant interest, actual military, commercial and other customers have been slow coming to the marketplace with firm orders, the airship manufacturers have been slow in developing and delivering advanced airships that meet their customer’s needs, and funding was prematurely curtailed for several ambitious projects. This uncertain business climate seems likely tochange by the early 2020s, when several different heavy-lift airships are expected to be certified by airworthiness authorities and ready for mass production and sale to interested customers.
Some of the advanced airship concepts being developed, especially for future heavy cargo carriers, will result in extremely large air vehicles on a scale we haven’t seen since the heyday of the giant zeppelins in the 1930s. Consider the following hybrid airships shown to scale with contemporary fixed-wing cargo aircraft.
Size comparison for hybrid airships required for various lift applications. Source: DoD 2012
In this post, we’ll take a look at the following advanced airship designs and concepts:
- Science Applications International Corporation (SAIC) Skybus 80K
- Aeros Aeroscraft Dragon Dream & ML866 / Aeroscraft Gen 2
- Northrop Grumman / Hybrid Air Vehicles HAV-3 & HAV-304 (LEMV)
- Hybrid Air Vehicles (HAV) Airlander 10 & 50
- Lockheed Martin P-791, SkyTug & LMH-1
- SAIC and ArcZeon International Unmanned Air Systems Carrier
- Dassault Systemes Commercial Flying Cruise Liner
- Zeppelin NT 07
The following table presents a summary of some key physical characteristics of these advanced airships.
The largest among this group of airships is the Airlander 50. As a point of reference, the gas envelope on the giant zeppelin Hindenburg was twice as large, at 200,000 cubic meters (7,062,000 cubic feet), but using hydrogen as the lift gas instead of helium as in the modern airships.
Among the airships in the above list, the following have actually flown: Skybus 80K, Dragon Dream, HAV-304, Airlander 10 prototype, P-791 and the Zeppelin NT 07. As of April 2019, the others in the list were under development or remain as concepts only. The Zeppelin NT 07 is the only advanced airship in this list that currently is flying regularly in commercial service. By the early 2020s, we likely will see several additional advanced airships on this list ready for sale to potential customers, the leading candidates being the ML866 / Aeroscraft Gen 2, Airlander 10 and LMH-1.
Now, let’s take a look at the individual advanced airships in this group.
SAIC Skybus 80K
The Skybus 80K was a proof-of-concept, non-rigid airship designed to carry a significant payload and fly autonomously on long duration missions. The goal of this program was to demonstrate greater persistence over target with a greater payload than was possible using an unmanned drone aircraft. Lindstrand USA was responsible for the Skybus 80K vehicle primary envelope and flight structure, which is similar in design and operation to a non-rigid Goodyear blimp (the version before the Zeppelin NT model LZ N007-101). All of the lift is provided by helium and the propeller is used only for propulsion.
Skybus 80K. Source: Lindstrand USA
In the Skybus 80K, the gas envelope is divided into a sealed main helium gas volume and separate gas volumes called “ballonets” that contain ambient air at atmospheric pressure. A simple airship like the Skybus 80K typically would be trimmed for neutral buoyancy.
To takeoff, fans would be used to vent some air from the ballonets, slightly reducing their internal pressure and mass, and allowing the helium gas volume to expand, with the net result of increasing buoyant lift.
As the airship gains altitude, external air pressure decreases, allowing the helium gas volume to expand within the gas envelope, into space previously occupied by the ballonets, which vent a portion of their air content overboard. The airship reaches its maximum altitude, known as its “pressure height,” when the helium gas volume has expanded to fill the gas envelope and the ballonets are empty. At this point, the airship’s mass is at a minimum, but the helium lifting gas can expand no further.
To descend, a fan is used to inflate the ballonets with outside air, adding mass and slightly compressing the helium into a smaller volume. This action decreases buoyant lift. As the airship continues to descend into the denser atmosphere, the helium gas volume continues to compress and the ballonets become proportionately larger. Ballonet inflation is controlled to manage buoyancy as the airship approaches the ground for a landing.
In flight, inflating only the fore or aft ballonet, and allowing the opposite ballonet to deflate, will make the bow or stern of the airship heavier and change the pitch of the airship. These operating principles are shown in the following diagrams of a blimp with two ballonets shown in blue.
Blimp with ballonets (blue). Source: zeppelinfan.de
Flying out of Loring Air Force Base in Caribou, Maine, the Skybus 80K met its program objectives for carrying 500 pounds (227 kg) to 10,000 feet (3,048 m) for 24 hours without refueling. While these may seem to be modest objectives, Skybus 80K was granted the first U.S. certificate for an unmanned experimental airship. This was an important milestone in the development of optionally manned airships.
You can see a short 2010 video of the Skybus 80K rollout and flight at the following link:
An SAIC concept for an full-scale optionally manned airship is shown in the following figure.
Optionally manned surveillance airship. Source: SAIC
Aeros Aeroscraft Dragon Dream and ML866 / Aeroscraft Gen 2
Igor Pasternak founded Worldwide Aeros Corp. (Aeros) in Montebello, with the goal of becoming a major manufacturer of lighter-than-air (LTA) craft in the U.S. Today, Aeros LTA products are used globally for military and commercial applications. They include the non-rigid Aeros 40D Sky Dragon airship and advanced tethered aerostatic systems. The firm’s website is at the following link:
In 2011, Aeros was awarded a $60 million contract from Defense Advanced Research Projects Agency (DARPA) for Project Pelican. Under this contract, Aeros developed their half-scale, proof-of-design vehicle named Dragon Dream, which embodied the following design features that also are incorporated on later Aeroscraft airships:
- Control-of-static-heaviness (COSH) system for variable buoyancy control;
- Rigid structure, with hard points for mounting the cockpit, propulsion system, aerodynamic control surfaces, and the cargo compartment;
- Ceiling suspension cargo deployment system for managing cargo with minimal requirements for ground support infrastructure. This system supports cargo containers and pallets from rails in the ceiling of the cargo compartment and adjusts cargo positioning to accommodate changes in center of gravity, such as when other cargo is loaded or unloaded;
- Air bearing landing system (ABLS) for operation on unimproved surfaces, including ice and water. Airflow in the system can be reversed to provide a suction to grip the ground and hold the airship in place;
- Vectored thrust engines;
- Low-speed control (LSC) system for managing the engines and maintaining position and orientation during vertical takeoff and landing (VTOL) and hover in low wind conditions
The aeroshell defines the boundary of the helium envelope. Within the aeroshell the COSH system manages airship buoyancy using the Helium Pressure Envelopes (HPE, the blue tanks in the following diagram) and Air Expansion Chambers (AEC, the grey bladders).
Aeroscraft cutaway showing HPE and AEC. Source: Aeros
The COSH variable buoyancy operating principle works as follows:
- To reduce buoyancy: The COSH system compresses helium from the aeroshell volume into the HPEs, which contain the compressed helium and control the helium pressure within the aeroshell. The compression of helium into the HPEs creates a negative pressure within the aeroshell, permitting the AECs to expand and fill with environmental air. The greater mass of the air within the aeroshell and the reduced helium lift make the Aeroscraft heavier when desired.
- To increase buoyancy:The COSH system releases pressurized helium from the HPEs into the aeroshell. This creates a positive pressure within the aeroshell, causing the AECs to compress and discharge air back to the environment. With reduced environmental ballast and greater helium lift, overall buoyancy of the Aeroscraft is increased when desired.
Also view a YouTube video describing the operation of the Aeroscraft and its variable buoyancy system here:
Dragon Dream was first “float tested” on 3 January 2013 inside a former blimp hanger at the Marine Corps Air Station in Tustin, CA. The airship was rolled out of its hangar on 4 July 2013 and taxi tests were conducted. All work under Project Pelican was completed within budget in August 2013. The Pentagon declared that the tests of the Dragon Dream were a success, with the craft meeting its demonstration objectives.
On 5 September, Aeros announced that the Federal Aviation Administration (FAA) had granted an R&D Airworthiness Certificate for Dragon Dream, permitting flight testing in designated controlled airspace. Dragon Dream and it made its first flight on 11 September 2013.
Dragon Dream in flight. Source: AerosDragon Dream in flight. Source: Aeros
The Dragon Dream airship was damaged in October 2013 when a partial roof collapse occurred while the airship was inside the blimp hanger. The airship was not repaired.
Aeros claims that the technologies demonstrated by the Dragon Dream will “enable the Aeroscraft to fly up to 6,000 nautical miles, while achieving true vertical takeoff and landing at maximum payload, to hover over unprepared surfaces, and to offload over-sized cargo directly at the point of need.” Operational Aeroscraft airships will be designed with an internal cargo bay and a cargo suspension deployment system that permits terrestrial or marine (shipboard) delivery of cargo from a hovering Aeroscraft, without the need for local infrastructure.
Discharging cargo from a hovering Aeroscraft airship. Source: Aeros
In September 2015, Aeroscraft CEO Igor Pasternak announced, “We are excited to reveal production is underway on the 555 ft (169 m) long ML866, and (we are) committed to achieving FAA operational certification for the first deployable Aeroscraft in approximately five years.”
Concept drawing, ML866 / Aeroscraft Gen 2 delivering cargo in the Arctic. Source: Aeros
On 8 August 2018, Aeroscraft announced that “they have completed the preliminary design phase for their Aeroscraft Gen 2 Cargo Airship”……”Aeroscraft Gen 2 will have enhanced buoyancy control, flight surfaces and modular cargo systems. The aircraft will feature zero emission operations, representing the only truly green technology capable of moving cargo over long distances. Aeros is now proceeding with the build and test phase on all major systems and subsystems for Aeroscraft Gen 2.” The Aeroscraft Gen 2 is being designed with great range (3,100 nautical miles; 5,741 km), a cruise speed of 100 – 120 knots, and an altitude ceiling of 12,000 feet (3,658 m).
The basic Aeroscraft design can be scaled up to handle much heavier cargo. The approximate scaling of an Aeroscraft airship as a function of cargo weight is shown in the following graphic.
Aeroscraft airship scaling to handle larger cargo loads. Source: Aeroscraft
Northrop Grumman / Hybrid Air Vehicles HAV-304 (LEMV)
Hybrid Air Vehicles (HAV) was formed in the UK in 2007 after acquiring the rights to airship technologies developed by its predecessor, SkyCat Group Ltd., and earlier predecessors dating back to 1971. The HAV website is here:
In 2008, the firm built and flew the small, unmanned HAV-3 hybrid airship demonstrator. The 50 foot (15 meter) long HAV-3 flew from 2008 to 2010 and served to validate the design of the much larger HAV-304 that was proposed by the team of Northrop Grumman and HAV for the U.S. Army’s Long Endurance Multi-Intelligence Vehicle (LEMV) program.
HAV-3 demonstrator in flight. Source: HAV via Aviation Week & Space Technology, 5 July 2010
In 2010, the Northrop Grumman / HAV team was awarded the LEMV contract to deploy a large, optionally manned airship capable of flying surveillance missions of up to three weeks duration at 20,000 feet (6,100 m) in uncontested airspace in conflict zones; initially in Afghanistan. An illustration showing the HAV-304 configured for the LEMV mission is shown in the following diagram.
LEMV airship mission concept, serving as a surveillance and communications hub. Source: US Army / Northrop Grumman
As a hybrid airship, the HAV-304 generated only part of its lift from helium, nominally 60 – 80%. The balance of the lift is generated by vectored-thrust propellers and by aerodynamic lift from the shaped gas envelope, which acts as a lifting body when the airship has forward speed. The helium gas envelope is slightly pressurized to maintain its aerodynamic shape. For the LEMV mission, the airship would transit at a maximum speed of 80 knots, and loiter in its designated operating area at 30 knots.
Hybrid airship sources of lift. Source: DoD 2012
This hybrid airship is negatively buoyant and cannot hover or make a vertical takeoff or landing. The HAV-304 takes off and lands on inflatable skids and requires a takeoff run of less than 1,000 feet (305 m). Airship trim is controlled much like in a conventional blimp, using multiple ballonets located fore and aft in each of the hulls.
The HAV-304 first flew on 7 August 2012 from Joint Base McGuire-Dix-Lakehurst in New Jersey, about 16 months behind its original schedule. Operations were terminated when the $517 million LEMV contract was cancelled in February 2013: “Due to technical and performance challenges, and the limitations imposed by constrained resources, the Army has determined to discontinue the LEMV development effort.”
Hybrid Air Vehicles bought the airship back from the Army in October 2013 for $301,000 and agreed to give the Army access to data from future civilian flights. After removing LEMV mission-related hardware, HAV returned the HAV-304 airship to the UK to continue developing this airship as the Airlander 10 prototype.
HAV-304 in flight. Source: Northrop Grumman
Hybrid Air Vehicles (HAV) Airlander 10 & 50
The Airlander 10 airship is the commercial reincarnation of the HAV-304 LEMV airship. Airlander 10 currently is the world’s largest aircraft, measuring 302 feet (92 m) long and 143 feet (43.5 m) wide. HAV describes the airship’s construction as follows:
“There is no internal structure in the Airlander – it maintains its shape due to the pressure stabilization of the helium inside the hull, and the smart and strong Vectran material it is made of. Carbon composites are used throughout the aircraft for strength and weight savings.”
A rigid structure running under the gas envelope supports the optionally-manned cockpit, flight control and mission systems, cargo and fuel. Weight from this rigid module is distributed across every frame of the airship via cables running across and into the hull as well as internal diaphragms.
Maximum payload capacity is 22,050 pounds (10,000 kg), which must be suspended externally from a centerline payload beam. Maximum speed is 80 kts (148 kph), maximum altitude is 16,000 feet (4,880 m), and manned mission duration is up to 5 days. Unmanned missions can be significantly longer.
Airlander 10 made its first two flights on 25 August 2016 from Cardington Airfield in Bedfordshire, UK. While the first flight went well, the second ended with an inauspicious soft crash landing with some damage to the airship, but no injuries to the crew.
Airlander 10 first flight. Source: CNNMoney.Closeup view of Airlander 10 in 2016 showing the side-mounted vectorable-thrust propellers and one of the landing skids. Source: Philbobagshot / WikipediaAirlander 10 soft crash landing after second flight. Source: Sky News
On 13 January 2019, the British Broadcasting Corporation (BBC) reported that HAV had retired the £32 million ($42 m USD) Airlander 10 prototype following successful final testing and achievement of key certification milestones with European civil aviation authorities.
- Design Organization Approval from the European Aviation Safety Agency (EASA) was received in October 2018
- Production Organization Approval from the Civil Aviation Authority (CAA) also has been received
HAV reported that, “the prototype served its purpose as the world’s first full-sized hybrid aircraft, providing us with the data we needed to move forward from prototype to production standard…… The full commercial model is expected to take to the skies with its first paying passengers in the early 2020s.”
You’ll find a Royal Aeronautical Society report on the first half of the Airlander 10 testing program, “Expanding the Envelope,” at the following link:
This report indicates that the all-weather capability of the Airlander 10, including anti-icing, would be tested in the second half of the test program. The report also suggests that the commercial Airlander 10 may have an enhanced thrust vectoring system that enables a (limited) VTOL capability.
A larger version known as Airlander 50 also is being designed with internal cargo bays capable of carrying up to 132,300 pound (60,000 kg) payloads. A concept drawing for Airlander 50 is shown below.
Airlander 50. Source: hybridairvehicles.com
More information on Airlander airships is available on the Hybrid Air Vehicles website at the following link:
Lockheed Martin P-791
The Lockheed Martin P-791 was one of the competitors in the U.S. Army’s LEMV program, which was won by the Northrop Grumman / HAV team with the HAV-304 hybrid airship.
Like the HAV-304, the P-791 tri-lobe hybrid airship flies under the combined influence of thebuoyant lift from helium, vectored thrust from propellers during takeoff and landing, and aerodynamic lift from the shaped gas envelope when the airship is in forward flight. The gas envelope is slightlypressurized to maintain its aerodynamic shape. The P-791 is not designed for vertical takeoff and landing or hover, since it depends on some aerodynamic lift being generated by the hull.
Rear quarter view of the P-791 in its hanger. Source: Al Sieb / Los Angeles Times / TNS
The first flight of the P-791 took place on 31 January 2006 at a Lockheed’s facility in Palmdale, CA. You can see a short video on the P-791 at the following link:
P-791. Source: Lockheed MartinP-791. Source: Lockheed Martin
When the P-791 is on the ground, it is heavier-than-air. To move the airship on the ground, its air cushion landing system (ACLS) operates in lift mode. The four air cushion pads on the bottom of the airship allow it to float on cushions of air and use the propulsion system to move the airship over almost any type of surface (pavement, unimproved natural surface like dirt, sand, snow or ice or water). The ACLS fans can be reversed and operated in suction mode, which enables the airship to “grip” a solid surface and remain stationary during ground cargo handling without the need for ground-based mooring / docking hardware.
You can see a short video on the operation of the ACLS here:
Lockheed Martin SkyTug and LMH-1
In March 2011, Lockheed Martin announced that it planned to develop a larger commercial version of the P-971, to be called SkyTug, which would be scaled up to carry at least 20 tons of cargo for the Canadian firm Aviation Capital Enterprises of Calgary. The first commercial airship was expected to be delivered in 2012, and future versions were expected to have larger cargo carrying capacity. According to Aviation Capital, “the fully vertical-takeoff-and-landing (VTOL) capable SkyTug will provide ‘greater payload and range at a fraction of the cost of a helicopter’. The larger ships that will follow apparently won’t be fully VTOL – they’ll require something of a run-up on the ground to generate dynamic lift and get airborne, rather as an airplane does.” Evidently, the VTOL version was to have powerful turboshaft engines to provide the needed lift, while the larger versions would have been more conventional hybrid airships.
Lockheed Martin SkyTug hybrid airship concept drawing. Source: Lockheed Martin
By 2015, reference to SkyTug seems to have disappeared and Lockheed Martin was promoting the LMH-1 as their next large commercial hybrid airship based on the P-791 design. As it currently is described by Lockheed Martin, the LMH-1 is designed to carry a crew of 2, up to 19 passengers or 21 tonnes (21,000 kg / 46,300 lb) of cargo at a maximum speed of 60 kts (111 kph) over a range of 2,593 km (1,400 nautical miles). The 18 m x 3.2 m x 3 m (59 ft x 10.5 ft x 9.8 ft) cargo compartment is a little bigger than the cargo box of the widely used Lockheed Martin C-130 Hercules fixed-wing cargo aircraft. The LMH-1 design can be scaled up to carry much heavier cargo.
LMH-1. Source: Lockheed MartinLMH-1 general arrangement. Source: Lockheed Martin
In November 2015, the U.S. Federal Aviation Administration (FAA) approved Lockheed’s certification plan for the LMH-1. Lockheed Martin also is working with Transport Canada on plans to a get the airship certified for use in Canada.
Lockheed Martin has engaged the sales firm Hybrid Enterprises to market the LMH-1. In September 2017, Lockheed Martin claimed it had Letters of Intent for 24 LMH-1 airships. First flight of the production airship is expected in 2019.
You can view a short video on the LMH-1 hybrid airship here:
An LMH-1 hybrid airship flying in the Arctic – concept drawing. Source: Lockheed Martin
SAIC and ArcZeon International Unmanned Air Systems (UAS) Carrier
Small, unmanned air vehicles (UAV), now commonly called unmanned air systems (UAS), can carry advanced sensors and weapons, but generally have short range. In spite of their range limitations, UASs can provide valuable and cost-effective capabilities for military planners and war fighters. At a recent conference is Washington D.C., DARPA Deputy Director Steve Walker asked the following question: “With the ranges we are looking at in the Pacific Theater, how do we get our small UAS to the fight?” Actually, he already knew the answer.
In March 2016, DARPA awarded the first contracts in support of its Gremlins program, which DARPA describes as:
“Gremlins (program)…… seeks to develop innovative technologies and systems enabling aircraft to launch volleys of low-cost, reusable unmanned air systems (UASs) and safely and reliably retrieve them in mid-air. Such systems, or “gremlins,” would be deployed with a mixture of mission payloads capable of generating a variety of effects in a distributed and coordinated manner, providing U.S. forces with improved operational flexibility at a lower cost than is possible with conventional, monolithic platforms.”
While the primary launch / recovery vehicle for this phase of the Gremlins program is a C-130 Hercules turboprop transport aircraft, the UAS launch and recovery techniques developed by the Gremlins program may be adaptable to other types of air vehicles, such as airships. Read more on the DARPA Gremlins program at the following link:
SAIC and ArcZeon International, LLC proposed a UAS carrier airship for this type of mission. A concept drawing for such an airship is shown below. No contract was awarded for development of this airship concept.
Airship deploying UAS. Source: SAIC / ArcZeon
Dassault Systems Commercial Flying Cruise Liner
The French firm Dassault Systemesposted an evocative advertisement in the a July 2016 issue of Aviation Week & Space Technologymagazine, with the following tag line:
“If we go on a cruise, does it have to be at sea level?”
Source: Dassault Systemes / Raybrennancreative.com
The image of a lighter-than-air cruise ship flying over snow-capped mountains looks like an airship builders dream from the mid-1930s, but with a distinctly modern airship design. The print ad concluded with the question:
“How long before the sky becomes the destination?”
While Dassault Systemes is not in the business of building airships, they have developed an integrated system called the 3DExperience platform to assist clients in developing “compelling consumer experiences.” I hope one of their clients likes the idea of a flying cruise liner. Let’s take a closer look at the airship.
Source: Dassault Systemes / Raybrennancreative.com
The closest you can come to an airship cruise today is a short commercial flight aboard a 12 – 14 passenger Zeppelin NT 07 airship, which is very similar in design to the new Goodyear airships. Friedrichshafen, Germany, home of the original Zeppelin factory, is the home base for Zeppelin NT.
The Zeppelin NT is longer than a Boeing 747-400 airliner. The airship’s primary structure weighs only about 1,000 kg (2,200 lbs) and the empty weight of a Zeppelin NT is about 6,622 kg (5,181 lb). In comparison, the empty weight of a Boeing 747-400 is 184,567 kg (406,900 lb).
Zeppelin NT & Boeing 747-400 size comparison. Source: Zeppelin NT
In normal operation, the Zeppelin NT operates with a slight negative buoyancy (i.e., the gas cells do not create enough buoyancy to make the Zeppelin NT lighter-than-air). At takeoff and landing, negative buoyancy is overcome with the application of engine power to three propellers (two flank, one stern) that have been vectored to generate the needed lift and some forward momentum. As forward speed increases, some aerodynamic lift is generated by the aeroshell and the propellers are rotated to deliver only propulsive thrust.
You’ll find detailed descriptions of the Zeppelin NT here:
In 2011 Goodyear replaced its aging fleet of GZ-20A non-rigid airships (blimps) with Zeppelin NT model LZ N007-101 semi-rigid airships. However, the name “Goodyear blimp” is still being used. You’ll find a very good illustrated history of the Goodyear blimp at the following link
Goodyear’s new “blimp” – the semi-rigid Zeppelin LZ N007-101. Source: Goodyear
My wife and I took a flight on the Zeppelin NT in early June 2017, on a clear blue sky day, one day after a modest wind and rain storm had passed through the Friedrickshafen area and temporarily grounded zeppelin flight operations. Clearly, weather is much more of an issue for flying zeppelins than it is for winged heavier-than-air craft. Nonetheless, in suitable weather conditions, flight in a zeppelin is a remarkable experience. Our short tourist flight in the Zeppelin NT was hardly an adequate basis for a zeppelin commercial business model. However, based on this flight, it’s much easier for me to visualize the utility of a large commercial airship for delivering cargo, passengers and emergency services to remote areas that are harder to reach with other modes of transportation.
One of the Zeppelin NT airships at the airfield in Friedrichshafen. Source: Author’s photoPreparing to land and change passengers. Source: Author’s photoTakeoff with flank thrusters in the vertical position for lift. Source: Author’s photoView of the German countryside from Zeppelin-NT. Source: Author’s photoView of Lindau on Lake Constance (the Bodensee) from Zeppelin-NT. Source: Author’s photoView of German countryside from Zeppelin-NT. Source: zeppelin-nt.de
You can book your flight on a Zeppelin NT at the following link: