Hybrid Air Vehicles HAV 304 Airlander 10

HAV 304 / Airlander 10
The Airlander 10 in Cardington Hangar on 21 March 2016
Role	Hybrid airship
National origin	United Kingdom
Manufacturer	Hybrid Air Vehicles
First flight	7 August 2012 (as HAV 304)
Status	Prototype
Number built	1
Unit cost	£25m[1]

The Hybrid Air Vehicles HAV 304 / Airlander 10 is a hybrid airship designed and manufactured by the UK company Hybrid Air Vehicles (HAV). Comprising an airship with auxiliary wing and tail surfaces, it flies using both aerostatic and aerodynamic lift. Powered by four diesel-engine driven ducted propellers, it is the largest aircraft flying today.

In its original form as the HAV 304, it was built for the United States Army's Long Endurance Multi-intelligence Vehicle (LEMV) programme. The requirement was for a medium-altitude long-endurance unmanned aerial vehicle able to provide Intelligence, surveillance, target acquisition, and reconnaissance (ISTAR) support for ground troops.^[2][3][4] The first flight took place in 2012 at Lakehurst, New Jersey, US. The LEMV project was cancelled in February 2013.^[5]

HAV reacquired the craft following the project cancellation and brought it back to RAF Cardington in England. It was reassembled and modified for civilian use, and in this form was redesignated the Airlander 10, returning to the air in August 2016.^[6][7] On 24 August, on its second test flight, the aircraft made a hard landing at Cardington Airfield, damaging its cockpit.

Development and design

Airlander 10 in January 2016

HAV 304 and the LEMV requirement

Following the successful demonstration of the HAV-3 small-scale demonstrator, and with Northrop Grumman as the prime bidder, the hybrid airship concept was accepted for the US Long Endurance Multi-intelligence Vehicle (LEMV) project, in preference to the Lockheed Martin P-791 also submitted.

Requirements included the capability to operate at 6 km (20,000 feet) above mean sea level, a 3000 km (2,000 mile) radius of action, and a 21-day on-station availability, provide up to 16 kilowatts of electrical power for payload, be runway independent and carry several different sensors at the same time. According to the U.S. Army, the LEMV was to have been a recoverable and reusable multi-mission platform. It could be forward located to support extended geostationary operations from austere locations and capable of beyond-line-of-sight command and control.^[2]

The developmental prototype emerged as the HAV 304, a helium-filled airship with twin conjoined hulls having a total internal capacity of 38,000 cubic metres.^[8] At 91 metres (299 ft) long, it is the longest aircraft in the world today;^[7] mid-20th century airships were longer, for example the German Hindenburg-class airships were 245 metres (804 ft) long.

The envelope is shaped as a lifting body to provide some aerodynamic lift when moving forwards under power. Additional aerodynamic surfaces comprise twin tail fins and rear winglets.

Thrust for flight and manoeuvring is provided by four ducted propellers, each driven by a V8 Diesel engine. Two units are located at the rear, while the remaining two sit alongside the forward fuselage.

In order to provide easy access for maintenance, the hybrid craft is able to land on an inflated pad. It uses aerodynamic lift like a conventional aeroplane in addition to aerostatic lift due to lighter-than-air gas helium in its envelope to take off. Once it is airborne, it may rely on the aerostatic lift only or add the aerodynamic lift created on the aerodynamic shape of its envelope due to forward motion through the air. Engines on board are used to propel it forward.

Northrop estimated that the biggest threat to the craft was weather, where high winds or thunderstorms could buffet the craft.^[9]

The craft was shipped to the US for final equipment fit and flight preparation.

Combined with an array of payloads—including ground moving target indication radar, electro-optical/infra-red sensors, communications relay, blue force tracking, signals intelligence, and electronic countermeasures—the LEMV would have augmented existing ISR (Intelligence, surveillance and reconnaissance) platforms to provide additional capabilities.^[3] The LEMV was intended to provide a possible solution to communications beyond the line-of-sight to the user, signals intelligence collection and almost any other type of payload configuration that meets the power, weight and size requirements.^[3] By providing this all-source sensor data to existing ground stations, the data would be available to multiple users and analysts.^[3] This interoperability with existing tasking, processing exploitation, and dissemination had the potential to improve information-poor situations, mitigating warfighter gaps and existing shortfalls through multi-intelligence sensor integration.^[3]

The LEMV would have enabled the American DoD to fly the most technologically advanced payloads in the near term as they became available.^[3] Northrop Grumman designed their system to integrate into the Army's existing common ground station command centers, and equipment used by ground troops in forward operating bases.^[10]

Airlander 10

Following cancellation of the LEMV project, the deflated HAV 304 was repurchased by HAV, returned to the UK and hangared at RAF Cardington.^[11] There it was reassembled, refurbished and modified for a more general role. No longer an example of the 304 design, it became the Airlander 10 prototype.

History

Origins of the LEMV concept

The costs involved in reconnaissance by fixed-wing aircraft flight were estimated in 2010 to be $10,000–20,000 per flight hour, plus an additional $10,000 in recapitalization costs.^[10] Helicopters are more affordable than their fighter equivalent, and can intervene like fighters if weapons are needed, but they are noisy and vulnerable, have very low endurance, and are still not cheap to operate.^[10] Hybrid airships can operate, like a helicopter, from any small forward base. Their operating cost is likely to be better than any other surveillance option, as is their endurance, which can be measured in weeks.^[10] The LEMV required at least 300 m (1,000 ft) of runway (violating the runway-independent requirement), and a tether point with a 100 m (300 ft) clear flat area around on which to park, which prevented them from operating at most large bases and all small bases.

They could serve as steady communications relays, for instance, ensuring that groups of soldiers in mountainous areas never lose contact with one another, even if they do not have direct line of sight to each other.^[10] LEMVs could have tracked important convoys, key roadways, or other key infrastructure as semi-permanent overwatch escorts, monitor an urban area of interest to prepare for major battles or enforce security, or focus on shutting down border chokepoints.^[10]

According to Alan Metzger, director for airship programmes at Northrop Grumman, the airship's ability to stay in the air for long periods made it perfect for surveillance missions. Speaking to The Engineer magazine, Metzger said that the LEMV was "going to be the longest endurance UAV in the world. There will be no gaps in the data that gets put down to the war-fighter."^[12] Northrop also said the LEMV could be used as a cargo aircraft, claiming that it had enough buoyancy to haul seven tons of cargo 3,900 km (2,400 mi) at 50 km/h (30 mph).^[13]

The LEMV project and the HAV 304

Test flight in 2012

The agreement to develop the project was signed on 14 June 2010, between the US Army Space and Missile Defense Command/Army Forces Strategic Command and Northrop Grumman.^[2] The agreement also included options for procuring two additional airships.^[2]

Northrop Grumman's subcontractors included:

• Hybrid Air Vehicles Ltd. in Cranfield, UK (HAV304 platform)
• Warwick Mills in New Ipswich, New Hampshire, US (fabrics engineering)
• ILC Dover in Frederica, Delaware, US (special engineering development and manufacturing company)
• Textron subsidiary AAI Corp. in Hunt Valley, Maryland, US (makes the US Army's OneSystem UAV/surveillance aircraft control & information distribution stations); and
• SAIC in McLean, Virginia, US.^[10]

The timeline for LEMV was an 18-month schedule starting in June 2010 that included vehicle inflation at about month 10.^[2] Additional operational characterization would have occurred at Yuma Proving Ground, Arizona, in month 16.^[2]

The US Army planned to demonstrate the first LEMV in Afghanistan 18 months after June 2010, with proposed plans to build five others following mission completion.^[3]

The overall concept struggled with constant time delays and technological challenges. In October 2011 Flight International reported that the LEMV was scheduled to make its first flight in November 2011.^[14] According to media reports the LEMV was then set up for its first flight in early June 2012^[15] but unspecified problems delayed the flight until August 7, 2012 over Joint Base McGuire-Dix-Lakehurst, New Jersey. The flight lasted 90 minutes and was performed with a crew on board. The first flight primary objective was to perform a safe launch and recovery with a secondary objective to verify the flight control system operation. Additional first flight objectives included airworthiness testing and demonstration, and system level performance verification. That put the combat deployment of the LEMV to Afghanistan in early 2013.^[16] Two months after the test flight, the US Army said it had concerns about sending the airship abroad. These included safety, transportation to the theatre of operations, and the timeline of deployment.^[17]

The project cost between $154 million and $517 million, dependent on all options.^[2] The cost included the design, development, and testing of the airship system within an 18-month time period, followed by transport to Afghanistan for military assessment.^[2]

On 14 February 2013, the Army confirmed that it had cancelled the LEMV development effort, citing technical and performance challenges, as well as the limitations imposed by lack of funds.^[18] Practical and theoretical knowledge gained was redirected from the LMEV to the JLENS program.^[19]

Reacquisition and the Airlander 10

The prototype Airlander 10, Martha Gwyn.

The US Army believed that the project's technical data and computer software could be useful for future projects but that selling it would save money.^[20] Hybrid Air Vehicles expressed an interest in purchasing the airship, saying they wanted to use it for cold-weather flights and other testing for the development of their proposed "Airlander 50" 50-ton cargo airship.^[21]

The HAV offer included the basic avionics, mooring masts and spare engines but not the specialist equipment or helium. With this the only offer on the table, in September 2013 the Pentagon sold the LEMV airship back to HAV for $301,000.^[6][20]

The deflated airship was returned to the UK, where it underwent reassembly and modification as the Airlander 10 prototype at RAF Cardington.^[7][22][23] The project received both UK and EU funding.^[24][25]

HAV announced the new type in March 2016, offering it for both civil and military use.^[26]

Named the Martha Gwyn after the company chairman's wife,^[27] the craft became popularly known as "the flying bum" for "the resemblance its plump front end shares with a human's back end."^[28]

Test flights and crash

The first test flight took place at the aircraft's home base, Cardington Airfield in Bedfordshire, England, on 17 August 2016, and lasted 30 minutes.^[29][30]

At the completion of its otherwise-successful, 100-minute second test flight, on 24 August 2016, the Airlander had an accident while landing at Cardington, meeting the ground nose-first and suffering extensive damage to the cockpit. The crew were reported to be "safe and well". The Air Accidents Investigation Branch opened an investigation.^[1][31]

Technical specifications

HAV 304

Source:^[32]

• Length: 91 m (298 ft 7 in)
• Width: 34 m (111 ft 7 in)
• Height: 26 m (85 ft 4 in)
• Envelope: 38,000 cubic metres
• Engines: four × 350 hp, 4 litre supercharged V8 diesel

Airlander 10

Data from hybridairvehicles.com^[33]

General characteristics

• Capacity: 10,000 kg (22,050 lb)
• Length: 92 m (301 ft 10 in)
• Wingspan: 43.5 m (142 ft 9 in)
• Height: 26 m (85 ft 4 in)
• Volume: 38,000 m³ (1,300,000 cu ft)
• Gross weight: 20,000 kg (44,092 lb)
• Powerplant: 4 × 4 litre V8 turbocharged diesel engines, 242 kW (325 hp) each

Performance

• Cruising speed: 148 km/h (92 mph; 80 kn)
• Endurance: 5 days manned
• Service ceiling: 6,100 m (20,013 ft)
  Loiter speed 20 knots (37 km/h)

See also

• Cargolifter heavy lift airship proposals
• JLENS airborne threat detector
• Lockheed Martin P-791 experimental hybrid airship
• TCOM Blue Devil US Air Force project for a reconnaissance airship
• Walrus HULA DARPA transport project
• Worldwide Aeros Corp Dragon Dream experimental rigid airship
• Zeppelin NT semi-rigid airship

References

External links

Wikimedia Commons has media related to Airlander.

• Official website
• "The new vehicle set to revolutionise the skies", BBC News, 4 January 2011
• "Airlander 10: is this the dawning of a new age of the airship?", The Guardian, 17 August 2016