Boeing 787-9 Dreamliner cleared for on-time delivery

Boeing Co said on Monday that regulators have certified the 787-9 Dreamliner, clearing the way for the new, stretched jet's on-time arrival to its first customer, Air New Zealand, possibly later this month.

Approval by the U.S. Federal Aviation Administration and the European Aviation Safety Agency came with exemptions for problems with two components that must be addressed, even though they will not prevent the plane from going into service, Boeing and the FAA said.

The green light for the 787-9, a longer version of the flagship Dreamliner that holds 40 more passengers, signals Boeing is making progress in putting behind it the production problems that dogged the smaller version, known as the 787-8.

"Certification of the 787-9 is confirmation that the airplane meets the highest levels of safety and performance, as demonstrated through a rigorous test program, including extensive laboratory validations, flight-test activities and thorough analysis and evaluation," Boeing said in a statement.

The 787-9, which sells for $250 million at list prices, has been keenly awaited by airlines trying to cut consumption of costly jet fuel with the new carbon-composite jet, and has garnered 40 percent of the 1,031 firm 787 orders placed so far.

The original 787-8 entered service in 2011, and another variant, the still larger 787-10, is due out in 2018.

But the latest version is still undergoing tweaks, even though the regulators have certified it as safe.

Boeing said part of a backup turbine system needs to be redesigned to account for a capacitor that failed during a flight test. The system, known as the Ram Air Turbine (RAT), is used to generate electricity and hydraulic pressure to ensure pilots can control the plane even if both engines fail. As a result of the test failure, the RAT has "a possibility of failing prematurely," Boeing said.

Given the "very low likelihood" of failure, the FAA granted an exemption for a limited time, Boeing said.

Similarly, a cockpit knob that controls altitude can inadvertently be rotated when pressed. That could send the plane out of its air traffic control-approved altitude, unless the pilots notice. "The limited time to detect the error causes a large reduction in safety margins, which is classified as 'hazardous,'" Boeing said.

The same design exists on the 787-8 and Boeing said it would develop a new knob design by May to make the part compliant with safety regulations, and then retrofit planes.

Boeing said the risk of the parts is balanced by the need to avoid a hit to export sales, and by the improved fuel economy of the plane, equipped with Rolls-Royce Trent 1000 engines. Both "will serve the public interest," Boeing said. (Reporting by Alwyn Scott; Editing by Marguerita Choy)