The giant Stratolaunch aircraft has successfully conducted its fourth test flight, flying over the southern California desert for nearly two hours, and billed as the largest aircraft in the world due to its 383-foot wingspan, taking off from Mojave Air and Space Airport in California at 15:23 EDT (18:23 GMT).
According to the British newspaper, "Daily Mail", the H-shaped plane stayed aloft for one hour and 43 minutes, reaching a maximum altitude of 15,000 feet (4,572 meters) and top speeds of 178 miles per hour, although it can reach 530 miles per hour.
The purpose of the test flight was to pull all the landing gear onto the plane for the first time, but the flight was interrupted due to a vibration problem and a warning light that went on an hour after the flight.
However, the plane returned to Mojave Airport and made four flights to ensure it was still operating as expected and to burn extra fuel before landing safely. Three people were on board the huge plane - two pilots and a flight engineer.
With a wingspan of 383 feet, it is wider than the length of a football field from goal to goal, which is approximately 345 feet.
It was also developed by the namesake company founded in 2011 by the late Microsoft co-founder Paul Allen, which is said to be aiming to have full operational capability by mid to late 2023, and once in operation, it will launch its top speed flight research vehicles. The speed of sound is reusable for paying customers.