THE largest plane ever built - the mighty Stratolaunch - is scheduled to take to the skies within the next few months.

The colossal aircraft, backed by Microsoft co-founder Paul Allen, is so big it requires two cockpits and six jet engines just to get it off the ground.

Paul told Wired: "When you see that giant plane, it's a little nutty."

He added: "You don't build it unless you're very serious, not only about wanting to see the plane fly but to see it fulfill its purpose. Which is getting vehicles in orbit."

He said he wanted to see it take flight "this fall".

With a wingspan which is longer than a football field at 385 feet it will eventually be used to transport rockets carrying satellites and astronauts into Earth’s upper atmosphere.

Matt Stinemetze, Scaled's chief engineer, said the plane is so large it is treated as a building.

He said: "The way California treats it, it is a building. It has to meet codes for sprinklers and electrical power."

It has already gone through two taxi tests in the past few months, with top speeds if 28mph and 46mph.

Three more tests are planned to see if can reach the required take off speed of 138mph.

Last summer, billionaire Allen revealed the visionary firm's ambitious plans for the giant record-breaking aircraft.

He told the Washington Post "I would love to see us have a full reusable system and have weekly, if not more often, airport-style, repeatable operations going."

When asked about the possibility of manned missions, Allen added: "If you caught the bug back in the Mercury era, of course it’s in the back of your mind.

"But I think you’re seeing right now, other than [space station] resupply missions, most spaceflights are about launching satellites. That’s the reality."

As well as sending cargo to space, the plane could be used to launch a secretive Shuttle-sized rocket codenamed 'Black Ice'.

Company officials at the conference confirmed that the 'Black Ice' concept is still under study but offered few details about it.

Stratolaunch plans to release more details about that “spectrum of services” in the next several months leading up to the plane’s first flight.

In the latest low-speed taxi test, conducted on February 25, 2018, all six of its 8,940lbs (4,000kg) engines were fired.

The main purpose of that test, which took place at California's Mojave Air and Space Port, was to put the aircraft’s ability to steer and stop through its paces.