EVERETT — The Boeing Co. has completed another round of tests on its 787 Dreamliner as it prepares the new aircraft for its first flight by July 1.

Over the last week, Boeing workers put the first Dreamliner through a series of ground tests called the “intermediate gauntlet.” During the testing, pilots and engineers simulated multiple scenarios using all airplane systems as if the aircraft were in flight, including power, avionics and flight controls. In an earlier round of tests, they fired up the engines.

“The team has done an incredible job supporting an exhaustive test regimen,” said Scott Fancher, vice president and general manager of the 787 program.

Test scenarios ranged from typical flight situations to single and multiple systems failures during flights. Intermediate gauntlet testing included about a week’s worth of operations on the airplane and hundreds of discrete test conditions.

Boeing has said its delayed Dreamliner will make its first flight by the end of June. With more than 800 orders for the mostly composite jet, Boeing hopes to deliver the first 787 early next year, nearly two years behind schedule. Boeing suffered through troubles with the 787’s global supply chain as well as production problems.

The company has another set of ground tests to conduct before it puts the 787 in the air.

“We will continue to take a hard look at the results, make adjustments and finish up our testing so we can get to first flight,” Fancher said.