Beset by everything from strikes to engineering difficulties, Boeing has again delayed its new 787 “Dreamliner” airplane.

Not long after it was officially announced in 2005, the Boeing 787 Dreamliner quickly became the fastest-selling airplane in history, with more than 600 planes sold in the first few years.

Originally scheduled to begin service in 2008, the plane is now already running at least two years behind schedule and Boeing won’t even be announcing a revised delivery date for several weeks as testing continues.

The reason for the delays is reported to be a need for reinforcement on the side of the aircraft’s body.

The plane uses new composite materials to make it lighter and more fuel-efficient, making it an attractive option for cost-conscious modern airlines.

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The non-rusting composite materials also allow a higher degree of humidity in the cabin. Cabins can be pressurized at 6,000 feet, compared to most other commercial aircraft which are pressurized at about 8,000 feet.

Meanwhile, Boeing’s archrival Airbus is looking to siphon off some the 787 customers with its new A350, a similarly sized plane offering similar fuel economy to airlines.

And already, many Dreamliner customers have been vocal with their concerns about delivery dates.

By Matthew Calcara for PeterGreenberg.com.

Previously: Boeing Strike Nears End, 787 Production Resumes

Related links: BusinessWeek, DailyFinance.com, Aviation Week