Boeing's 787 fleet is a step closer to getting back in the air after a test flight that went "according to plan".
The plane maker yesterday used a Dreamliner it built for Poland's LOT airline on the 2hr 9min flight from its manufacturing base near Seattle in Washington state.
"Today's flight was a normal Boeing production check flight intended to validate that all systems function as designed," a Boeing spokesman said. "The crew reports that the flight went according to plan."
The plane took off about an hour later than planned from Paine Field, flew out over the Pacific and down the coast to Oregon reaching an altitude of 11,800m before returning to the airfield.
During the flight crews cycled the landing gear and operated all the backup systems, in addition to performing electrical system checks.
After analysing the results, Boeing plans a certification demonstration flight that will be used to show that the "new battery system performs as intended during flight conditions".
Boeing's fleet of 50 Dreamliners was grounded across the world in January after batteries overheated.
A short circuit started a fire on a 787 parked at Boston's Logan Airport and smoke from a battery forced an emergency landing in Japan.
The company is under pressure to resume deliveries and production of the Dreamliner for which it has a backlog of 800 aircraft, including Air New Zealand which has 10 of the next model of the plane on order. The carrier has said it remains confident it will get the first of its 787s by the end of next year.
The Dreamliner's extensive use of electrical power, which helps boost fuel efficiency, led Boeing to choose lithium-ion batteries, which also power mobile phones.
The US safety regulator, the Federal Aviation Administration, on March 12 approved Boeing's plan for testing the batteries which it said was the first step in the process to evaluate the 787's return to flight.
Boeing has said its fix includes the addition of new insulation materials, stepped-up production and testing processes and a containment system.
Its chief project engineer Mike Sinnett said earlier this month it had come up with a comprehensive set of solutions.
"We have found a number of ways to improve the battery system and we don't let safety improvements go once they are identified. We incorporate them into our processes and products."
The company is teaming up with the battery's supplier in Japan to better monitor the manufacturing process .
The batteries will not be charged as highly and the charger will also be adapted to soften the charging cycle to put less stress on the battery.
Airlines including Air India and Japan's ANA have said they will seek compensation in cash from Boeing for having their aircraft grounded.
Boeing has already offered discounts and other deals to airlines after deliveries were delayed three years because of research and manufacturing delays.
Ground staff on guard for ramp rash
Airport ground staff are being trained to identify and report damage to new-generation carbon composite planes that is harder to spot than on aluminium-body aircraft.
Damage caused by loading vehicles is known as "ramp rash" and costs the industry about US$4 billion ($4.8 billion) a year, the International Air Transport Association (Iata) was told.
Dings and dents to traditional aluminium-body aircraft are relatively easy to spot but difficult to see in composite materials - used in new generation aircraft such as the Boeing 787 Dreamliner and the yet-to-fly Airbus A350.
Iata's senior vice-president of safety operations and infrastructure, Gunther Matschnigg, said clear guidelines had been set between aircraft makers and ground handling and servicing workers on ramps or aprons where aircraft park.
A Boeing spokeswoman said composite materials had been used in commercial aircraft for decades and were tougher than aluminium.
The 787 had been designed with an adequate strength margin to retain certification load capacity even with non-visible damage present, she said.
Depending on the findings of a visual inspection, additional techniques, such as an ultrasonic inspection, may be required.