• The dream of building world’s largest aircraft is a step closer to reality with the private spaceflight company Stratolaunch, which is spearheading the project, having successfully hit a milestone last week by completing the first phase of engine testing.
• Stratolaunch was founded by Paul G. Allen, the man who funded first private spacecraft SpaceShipOne to carry a civilian into suborbital space and safely home again. 
• It aims at providing convenient, reliable, and routine access to low Earth orbit (LEO) that will help researchers collect data in science, research, and technology from space.
• The team has completed fuel testing that includes testing all six fuel tanks to ensure proper operations and each of the six fuel tanks were filled independently to ensure proper operations of fuel mechanisms and to validate the tanks were properly sealed.
• The company said that they have also begun testing the flight control system and have so far exercised the full limits of motion and rate of deflection of control surfaces on the wing and stabilisers.
• The engine testing was conducted with a build-up approach consisting of three phases – dry motor, wet motor and then each engine was started one at a time and allowed to idle. 
• Each of the engines operated as expected.
• The company would “continue to test the aircraft’s engines at higher power levels and varying configurations, culminating to the start of taxi tests.”

World’s Largest Aircraft “Stratolaunch”

• It is the world’s largest aircraft by wingspan and is the largest all-composite plane ever built, according to Stratolaunch website.
• It uses “Boeing 747 engines for a payload capacity of over 500,000 lbs
• It has an operational range of approximately 2,000 nautical miles.
• Stratolaunch is expected to be fully operational by the end of this decade.
• It is currently under construction at the Mojave Air & Space Port in Mojave, California.