A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. The world's largest aircraft has been unveiled for the first time since being fully assembled in the UK. The 302ft (92m) long Airlander 10 – part plane, part airship – was floated in a First World War hangar in Bedfordshire. The ship was first developed for the US government as a long-endurance surveillance aircraft but it fell foul of defence cutbacks. British firm Hybrid Air Vehicles (HAV) launched a campaign to return the Airlander 10 to the skies in May 2015 and it will now carry out ground testing before 200 hours of test flights begin later this year. The vessel was filled with 1.3 million cubic feet of helium – enough to fill 15 Olympic-sized swimming pools – in a test run last October. The date of the test flight has not been announced but the craft will be restricted to a 70-mile (112km) radius. If successful, an aircraft based on this prototype will go into production. (Photo by Darren Staples/Reuters)





A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. (Photo by Darren Staples/Reuters)





A worker walks alongside the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. (Photo by Darren Staples/Reuters)





Members of the media film the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. (Photo by Darren Staples/Reuters)





Test pilot David Burns sits in the cockpit of the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. (Photo by Darren Staples/Reuters)





The Airlander 10 airship, the world's largest aircraft, is unveiled for the first time since being fully assembled at Cardington hanger in Bedfordshire on Monday March 21, 2016. The 302ft (92m) long part plane, part airship was first developed for the US government as a long-endurance surveillance aircraft. (Photo by Chris Radburn/PA Wire)





The Airlander 10 airship is pictured airborne in its hangar during its media launch at Cardington Airfield in Shortstown near Bedford on March 21, 2016. The Airlander, which was originally developed for the US military, is 300 feet (91 metres) long, according its British maker Hybrid Air Vehicles. The Airlander is essentially three streamlined airship-type bodies merged into one with wings and rotary engines. (Photo by Adrian Dennis/AFP Photo)





A worker stands under the Airlander 10 hybrid airship during its unveiling in Cardington, Britain March 21, 2016. (Photo by Darren Staples/Reuters)