Comprising a helium airship with auxiliary wing and tail surfaces, it flies using both aerostatic and aerodynamic lift and is powered by four diesel engine-driven ducted propellers.

The modified aircraft completed design certification testing before being written off [2] when it came loose from its moorings in a high wind on 18 November 2017 at Cardington Airfield.

[8][9] The LEMV programme was intended to demonstrate a medium-altitude long-endurance unmanned aerial vehicle capable of providing Intelligence, surveillance, target acquisition, and reconnaissance (ISTAR) support for ground troops.

[10][11][12] Besides HAV, UK and US subcontractors included Warwick Mills (fabric engineering and development), ILC Dover (specialised engineering development and manufacturing services), Textron subsidiary AAI Corporation (US Army OneSystem UAV/surveillance aircraft control & information distribution station), Stafford Aero Technologies (flight control systems) and SAIC (full-motion video processing).

[13] Requirements included the capability to operate at six kilometres (20,000 ft) above mean sea level, a 3,000-kilometre (1,900 mi) 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.

[10] The developmental prototype emerged as the HAV 304, a helium-filled airship with twin conjoined hulls having a total internal capacity of 38,000 m3 (1,300,000 cu ft).

[8] The airship could serve as a steady communications relay, ensuring that groups of soldiers in mountainous areas would never lose contact with one another, even if they do not have direct line of sight to each other.

[21] The type had the potential for various civil and military applications; these include transportation purposes, conducting aerial surveillance, acting as a communications relay, supporting disaster relief operations, and various passenger services such as leisure flights and luxury VIP duties.

[6] The Airlander 10 possesses a sizeable flight deck with four large floor-to-ceiling windows, providing a high level of external visibility.

[20] While the airship had originally been envisioned to be unmanned, HAV adopted an optionally piloted approach as a result of customer interest in such operations.

In 2015, positions for a single pilot and an observer had been installed in the Airlander 10; HAV intend to adopt a twin-pilot configuration along with a greater prevalence of glass cockpit-style controls and instrumentation in the future.

Garmin-built avionics furnish the cockpit; the suite includes a closed-circuit television system that enables the pilot to view the otherwise-distant engines.

[20] The propulsion units and flying surfaces are both connected to the flight control system via fly-by-optics, using optical fibre cables to efficiently cope with the vast scale of the vehicle.

[20] The hull is internally divided by diaphragms into a total of six main compartments with additional sub-divisions; these divisions can be sealed in the event of emergencies, such as battle damage being sustained, allowing for the majority of the airship's helium, and thereby lift capacity, to be retained.

[20] According to estimates performed by Northrop, the biggest foreseen threat to the HAV 304 is adverse weather conditions, such as high winds or thunderstorms, that could buffet the craft.

[19] The skin is reportedly capable of handling small arms fire and other causes of tears due to a level of built-in redundancy and the relatively-low pressure difference between the inside and outside of the hull.

[6] The Airlander 10 is powered by a total of four Thielert Centurion 325 hp (242 kW) V8 diesel engines which drive sets of three-bladed ducted propellers to provide the thrust for both flight and manoeuvring.

[citation needed] Due to the hybrid aerostatic/aerodynamic lift approach, fuel can be expended without entering a state of positive buoyancy that would necessitate routine helium venting in order to land, a costly weakness present upon conventional airships.

[20] On 14 June 2010, the agreement for the development of the project was signed between the US Army Space and Missile Defense Command/Army Forces Strategic Command and Northrop Grumman.

[citation needed] On 7 August 2012 the LEMV, carrying US Army registration 09-009, conducted its maiden flight over Joint Base McGuire-Dix-Lakehurst, New Jersey.

[27][28] Two months after the test flight, the US Army stated that it had concerns about sending the airship abroad; these included safety, transportation to the theatre of operations, and the timeline of deployment.

[11] In October 2012, the Government Accountability Office (GAO) stated that the LEMV project was 10 months behind schedule due to a combination of factors, including issues with fabric production, foreign components being cleared through customs, and the impact of adverse weather conditions.

[30][31] In a statement made by a US Army Space and Missile Defense Command spokesperson, the cancellation was a result of technical and performance challenges that had been encountered, as well as resource constraints that had come into effect.

[39] At one point, HAV had intended for the airship to have completed reassembly and be ready for test flights by December 2014; however, delays were encountered while additional financing from commercial and government entities was being sought.

[19] Re-registered as G-PHRG, on 21 March 2016 the fully assembled Airlander 10 was publicly unveiled; at this point, HAV announced that the type would be offered for both civil and military use in the future.

[49] On 18 November 2017, the airship broke free from its moorings in a high wind, automatically pulling a safety rip panel so that it deflated and fell to the ground.