Boeing's new 787 jetliner has completed its maiden flight, more than two years behind schedule.

The plane took off at 10 am local time on Tuesday, at Everett's Paine Field in the US state of Washington. Thousands of Boeing employees, potential buyers and airline executives, were present to watch the inaugural flight.

The tests are expected to last about nine months and will subject the planes to harsher conditions than found in normal flights. The plane was designed to produce fewer emissions and will use 20 percent less fuel than comparable aircraft.

It has a more comfortable cabin with better air quality and larger windows. But the 787 aircraft has been plagued by numerous problems and delays regarding parts and equipment. Tuesday's test flight was crucial for Boeing to allay worries from investors.

Richard Tortoriello, Aerospace Analyst, said, "Reason that it is important that Boeing get the test, the plane approved and into the air is that every day that it is not in the air and not being delivered, is another day that Boeing has to make supplier payments, they have to make payments to the airlines for late delivery. Of course they want to minimize that and get the programme rolling."