Taking a leap of technology, the Indian Air Force is now looking for hydrogen-powered autonomous plane that will have the ability to fly for longer periods of time and provide continuous surveillance.The IAF has invited bids from Indian companies to indigenously design, develop and manufacture a plane that can fly at an altitude of some 30,000 feet and carry a load up to 5,000 kg.  It will have multiple people participating and the best among those will be picked up as the final partner to produce the plane.   The Indian company can have a foreign supplier but a minimum indigenous content of 50 per cent  needs to be maintained.  Indian vendors can send their proposals by April 30.The IAF has named it ‘Medium Altitude Heavy Lift Airship’, which will be pilot-less.  The IAF intends to partner with indigenous defence production industry to undertake the project.The IAF has specified that the airship platform, preferably needs to be operating on hydrogen. The platform would be utilisedtop towards carrying out persistent intelligence gathering and reconnaissance, and provide communication akin to airborne radars and electronic warfare planes.The ‘airship’ needs to have a capability to operate special payloads and act as a launch base and platform for missiles and drones while in flight.Hydrogen is preferred as it is lighter than air, cheap, non-toxic, abundantly available, has high energy density and is a clean combustion product (only water vapour), the IAF has explained.The IAF is looking at future technology and seeks a hybrid propulsion,  preferably hydrogen fuel-based and supported by solar power, battery or fuel cell and having the endurance of a  minimum of 10 days, besides having the capability to ‘auto launch’ and recover from prepared and unprepared surfaces.The airship needs to have line of sight communication of at least 250 km or operate through satellites. The IAF has not given the numbers it seeks.Requirements from the industry include a strong financial and technical base to undertake the project.The bidders need to have manufacturing infrastructure, along with in-house design capability, production capability or project management.