SEATTLE – It looks like a bloated 747, one that tried to eat another airplane. Or maybe a flying green whale.

The huge airborne freighter built to ferry pieces of the Boeing Co.’s new 787 jetliner around the globe floated out of Saturday’s chilly morning sky and hit the runway. The aircraft dwarfed nearby 737s as it taxied at Seattle’s Boeing Field after its first long flight from Taiwan.

But the arrival of the 747-400 Large Cargo Freighter signals that the 787 is a step closer to coming together, with parts scheduled to be delivered early next year.

For that reason, Boeing employees – some of whom gathered to watch its arrival here – could get past its looks.

“It’s incredible. I’m so happy, I’m going to kiss it,” said Cynthia Dee of Mukilteo, who works in Boeing’s Global Partners department and helped track down parts for the freighter. She stood next to the runway and smiled widely as it landed.

She was joined in that expression by Mike Bair, general manager of the 787 program, and Scott Strode, vice president of development and production for the model.

“This is truly a significant milestone for us on the 787 and at Boeing.

“These planes will be a cornerstone,” Strode said. “It’s one of our most visible milestones this year for the 787 because we have to have it certified and ready to ship hardware by early next year.”

When 787 production is in full swing, three of the modified 747s will haul fuselage sections, wings and other large parts of the 787 between points in the U.S., Japan and Italy. Boeing has estimated that flying the large parts will save 20 percent to 40 percent on shipping costs and be faster.

“These planes are a sizable investment,” Strode said. “But when you compare the costs of delivery by sea and the cost of delivery by this airplane, it makes very good business sense.”

The second of the three 747s that Boeing is having modified by Taiwan’s Evergreen Aviation Technologies Group should be completed by the year’s end.

The third will come sometime after that. Once they’re all tested, the small fleet will be run by Evergreen for Boeing.

The 747s that Boeing bought from commercial airlines all date back to the early 1990s. Besides the radical changes to the airplane’s body that allow it to hold three times the volume of an unaltered 747 freighter, it has some things in common with the passenger version of the jetliner. The engines are the same, and it carries about the same amount of fuel.

“When you’re sitting in the pilot seat, you can’t tell the difference between this and any other 747,” said Joe MacDonald, Boeing’s chief 747 pilot and captain of the Taipei-to-Seattle flight. “Taking off and landing are virtually identical. I couldn’t detect a difference.”

In this freighter, however, the passenger space is limited to the flight deck, which holds three crew members piloting the plane. That part is also the only pressurized portion of the plane.

Also, the entire back section is connected to the rest of the plane by only two stainless steel hinges. That allows the back to swing open for easy loading and unloading of giant airplane parts.

The interior of the long cargo space, with a 26-foot-high curved ceiling, resembles a small cathedral when empty. Kurt Kraft, chief project engineer for the Large Cargo Freighter, pointed out daylight seeping through the point where the swinging aft section and the rest of the plane meet. There’s no tight seal necessary because the carrying space is not pressurized during flight, he explained.

Angel Rodriguez, flight test manager for Boeing, stood inside the freighter shortly after it landed and took it all in.

“When I looked at it and read it, I said it’d never fly. Now here it is,” he said. “It is a wonderful piece of engineering.”

MacDonald said the freighter took three test flights around Taiwan before the 13-hour haul across the ocean. The plane took Saturday’s flight slower than usual because it hasn’t been fully tested. But the flight itself was uneventful. One of three units that air conditions and pressurizes the flight deck failed, a minor glitch, he said.

The aircraft will be put through more rigorous paces in the months to come, completing a 250-hour flight test regimen in Seattle and California. At Everett’s Paine Field, the swinging cargo door will be opened and tested for the first time in the weeks to come. Boeing hopes the aircraft gains Federal Aviation Administration certification by late December.

MacDonald didn’t comment on whether he’s come up with a nickname for the aircraft. Strode admitted there are “a lot of unofficial” names, adding Boeing is working on a catchier name for the plane than Large Cargo Freighter.

“I’ll admit it’s not the prettiest airplane in the world,” MacDonald said, referencing the plane’s unfinished-exterior look, consisting mostly of primer at present. “But it’s such an important part of the company’s business plan going forward that you have to look beyond the green paint.”